PART 2: TECHNICAL NOTES · Type 1 nutrient deficiencies result in specific deficiency dis-eases, do not always affect growth, but will affect metabolism and immune competence before

PART 2: TECHNICAL NOTES

The technical notes are part two of four parts contained in this module. They provide an introduction to micronutrient malnu-trition. The technical notes are intended for people involved in nutrition programme planning and implementation. They providetechnical details, highlight challenging areas and provide clear guidance on accepted current practice. Words in italics areexplained in the glossary.

SummaryThis module provides an overview of micronutrient malnutrition and the methods used for its assessment. The commonmicronutrient deficiency diseases (MDD) are reviewed and their clinical signs are illustrated. Direct and indirect assessmentmethods for detecting micronutrient malnutrition are described and the continuing public health significance of micro-nutrient malnutrition is emphasised.

1HTP, Version 2, 2011

Micronutrient malnutritionMODULE 4

Key messages

1. Micronutrient malnutrition continues to affect populations in many parts of the world. It is often exacerbatedin emergencies and is a significant cause of morbidity, mortality, and reduced human capital.

2. The main cause of micronutrient malnutrition is usually an inadequate dietary intake of vitamins or minerals.

3. Food aid rations have often failed to meet Sphere standards for micronutrient adequacy. A low diversity dietwith the absence of micronutrient-fortified foods is a strong predictor of MDD.

4. Infections are an additional and important cause of micronutrient malnutrition and can negatively affectnutritional status by increasing nutrient requirements and reducing nutrient absorption.

5. Globally, iron deficiency anaemia is the most common micronutrient disorder. Large numbers are also affectedby iodine and vitamin A deficiencies. These endemic deficiencies often affect populations in emergencies.

6. In addition, epidemics of MDD such as pellagra, scurvy, beriberi, and ariboflavinosis occur in populations affectedby severe poverty or experiencing crisis.

7. Assessment of micronutrient deficiencies can be conducted using either direct or indirect approaches.

8. Appropriate ration planning and monitoring of food assistance programmes can greatly reduce the risk ofmicronutrient malnutrition. Software tools such as NutVal are available to assist in this task.

9. Ensuring that micronutrient deficiency diseases are monitored as part of the health information system isan important part of effective surveillance.

10. Major challenges exist in conducting investigations of MDD outbreaks. Specialist approaches may be requiredto accurately identify and quantify the extent of MDD.

TECHNICAL NOTES

2 HTP, Version 2, 2011

MODULE 4 Micronutrient malnutrition

Food Security and Nutrition Assessment Standard 2: NutritionWhere people are at increased risk of undernutrition, assessments are conducted using internationally accepted methodsto understand the type, degree and extent of undernutrition and identify those most affected, those most at risk, andthe appropriate response.

Food Security, Food Transfers Standard 1: General nutrition requirementsEnsure the nutritional needs of the disaster-affected population including those most at risk are met.

Key indicators

• There is adequate access to a range of foods, including a staple (cereal or tuber), pulses (or animal products)and fat sources, that together meet nutritional requirements

• There is adequate access to iodised salt for the majority (> 90%) of households

• There is adequate access to additional sources of niacin (e.g. pulses, nuts, dried fish) if the staple is maizeor sorghum

• There is adequate access to additional sources of thiamine (e.g. pulses, nuts, eggs) if the staple is polished rice

• There is adequate access to adequate sources of riboflavin where people are dependent on a very limited diet

• There are no cases of scurvy, pellagra, beriberi or riboflavin deficiency

• The prevalence of vitamin A deficiency, iron deficiency anaemia and iodine deficiency disorders are not of publichealth significance

Source: The Sphere Project (2011). Humanitarian Charter and Minimum Standards in Humanitarian Response. Geneva: The Sphere Project.

These technical notes are based on the technical references given in the resource list for the module and the Sphere standardsshown in the box below:

Sphere standard

1 WHO (2009) Global prevalence of vitamin A deficiency in populations at risk, 1995-2005 World Health Organisation: Geneva2 WHO (2004) Iodine Status Worldwide World Health Organisation: Geneva

IntroductionMicronutrient deficiencies are widespread in developingcountries with more than two billion people affected. For ex-ample, children continue to go blind due to vitamin A defi-ciency and about 33 per cent of preschool children in develop-ing countries have sub-clinical deficiency.1 Globally, about 16per cent of people in the general population are affected bygoitre, mainly due to insufficient consumption of iodine.2 Iodinedeficiency causes not only widespread endemic goitre but alsoretards growth and physical development; in its extreme form,this retarded growth is known as cretinism. Iron deficiency ana-emia – characterised by breathlessness and fatigue – is highlyprevalent worldwide with about 1.6 billion affected people.Unlike deficiencies in vitamin A and iodine, anaemia occurswidely in both industrialized and developing countries.

Micronutrient deficiencies occur more frequently in individualson a monotonous or restricted diet or in those with infections.Both these problems are characteristic of most emergency sit-

uations. Micronutrient deficiencies have been reported foryears in emergency settings and especially in refugee camps,where they have been most frequently assessed (see table 2).Some deficiency diseases, such as anaemia and vitamin Adeficiency, primarily affect children and women, while others,such as pellagra, are found more frequently in adult femalesand males. Micronutrient deficiencies have also been docu-mented in adolescents in African refugee camps.

Micronutrient deficiencies have many detrimental effects suchas an increase in morbidity (illness) and mortality (death) riskas well as impaired growth and mental development. Eradica-ting micronutrient deficiencies is a fundamental componentof any public health intervention.

This module covers the recognition and assessment of micro-nutrient malnutrition and micronutrient deficiency diseases.Approaches to treatment and prevention strategies for micro-nutrient deficiencies are covered in module 14.

TECHNICAL NOTES


MODULE 4Micronutrient malnutrition

Table 1: Definitions

Definitions Concepts

Micronutrient malnutrition: Micronutrient malnutrition can exist even when theThe existence of sub-optimal nutritional status due to a lack energy and macronutrient needs of an individual areof intake, absorption, or utilisation of one or more vitamins met. For that reason it is often referred to as ‘hiddenor minerals. Excessive intake of some micronutrients may hunger’. People may appear well fed but still bealso result in adverse effects. suffering from debilitating and life threatening

malnutrition.

Micronutrient deficiency disease (MDD): When certain micronutrients are severely deficientA clinical disease that arises due to a lack of intake, specific clinical signs and symptoms may develop.absorption, or utilisation of one or more vitamins The classic nutritional diseases such as scurvy,or minerals. beriberi and pellagra are good examples of these

sorts of disease.

Note: The term micronutrient deficiency disorder is also used when referring to micronutrient malnutrition and MDD.

Table 2: Examples of micronutrient deficiencies reported in emergency situations

Location Years

Vitamin C deficiency Somalia* 1982, 1985Sudan* 1984, 1991Ethiopia* 1989Kenya* 1994, 1996Afghanistan 2001, 2002

Vitamin A deficiency Sudan* 1985, 1987Kenya* 1998, 2001Nepal* 1999Ethiopia* 2001Uganda* 2001

Niacin deficiency Malawi* 1989, 1990, 1991, 1996Angola (internally displaced persons) 1999, 2000Angola 2002

Anaemia Kenya* 1998, 2001Nepal* 1999Uganda* 2001Ethiopia* 2001Algeria* 2002Thailand* 2001-2002Jordan* 1990Lebanon* 1990Syria* 1990Gaza* 1990West Bank* 1990

Thiamine deficiency Thailand* 1992Nepal* 1994-1995Kenya (internally displaced persons) 2000

Source: NICS (2007) Assessing micronutrient deficiencies in emergencies: Current practice and future directions Geneva: SCN

* In refugee camps

TECHNICAL NOTES



The main micronutrients and associateddeficiency diseasesMicronutrients include all vitamins and the minerals that areessential for human health. They are required in only small am-ounts but, nonetheless, are essential for life and needed for awide range of normal body functions and processes. Vitaminsare either water-soluble (e.g. the B vitamins and vitamin C) orfat-soluble (e.g. vitamins A, D, E and K). Essential mineralsinclude iron, iodine, zinc, calcium, and a large number of others.

Micronutrients are found in different amounts in differentfoods. Some micronutrients are widely available in a range offoods. Others, such as vitamin C, may be found only in certaintypes of food. A deficiency of a particular micronutrient is morecommon when it is only found in a limited range of foods andthese are not available to the whole population.

Micronutrients can be categorized as either Type 1 or Type 2nutrients.

Type 1 nutrient deficiencies result in specific deficiency dis-eases, do not always affect growth, but will affect metabolismand immune competence before signs are apparent. Thiscategory of nutrients includes vitamins A, B1, B2, B3, B6, B12,C, D, and folic acid, as well as iron, calcium, copper, iodine, andselenium.

Type 2 nutrient deficiencies do not show specific clinical signs.They affect metabolic processes and result in growth failure,wasting, increased risk of oedema, and lowered immune res-ponse. This category of nutrients includes sulphur, potassium,sodium, magnesium, zinc, phosphorus, water, essential aminoacids, and nitrogen deficiencies.

Table 3 lists nine of the most important micronutrients, theirfunctions, sources, and signs of deficiencies. Bear in mind thatthere are also other micronutrients (e.g. selenium and theothers listed above) that are extremely important for humannutrition, but these nine are considered to be of particularimportance in an emergency context.

The micronutrient requirements of an individual depend onage and sex. Nutrient requirements may also increase duringcritical period of rapid growth and development (pregnancy,lactation, infancy and early childhood) as well as during certainillnesses and diseases (such as malaria, diarrhoea, tuberculosis).

Annex 1 contains tables of vitamin and mineral requirementsrecommended by the World Health Organisation (WHO) andthe Food and Agricultural Organisation (FAO) for populations.

While we are usually concerned about people not receivingan adequate amount of micronutrients in their diet, it shouldnot be forgotten that there is a risk of toxicity with excessiveintakes of some micronutrients. For example, a high intake ofvitamin A is especially dangerous for pregnant women as dam-

age to the growing baby can occur. For this reason, high dosesupplements of vitamin A are not usually given to pregnantwomen unless they are exhibiting clinical sign of deficiency(see module 14).

Approaches to the assessment ofmicronutrient deficienciesThere are two main approaches to assessing micronutrient de-ficiencies in emergencies, indirect and direct assessment.

• Indirect assessment involves the estimation of nutrientintakes at a population level and extrapolating from thisthe risk of deficiency and the likely prevalence (rate) andpublic health seriousness of MDD.

• Direct assessment involves the measurement of actualclinical or sub-clinical deficiency in individuals and thenusing that information to give a population estimate ofthe prevalence of the MDD.

Indirect Assessment

The indirect assessment approach involves two stages. Firstly,the dietary intake of the population of concern needs to bemeasured or estimated and, secondly, this intake has to becompared with the nutrient requirements of the population.

Nutrient intake values (NIV) provide guidance about the nutri-ent intakes that healthy individuals require. Countries maypublish different NIV and there may be large differences intheir values.

The NIVs that are currently recommended by WHO and FAOare called Reference Nutrient Intakes (RNI). These RNI werepublished in 2004 and are given in the table in Annex 1. It isimportant to note that older WHO recommendations foremergency affected populations, called Safe Levels of Intake(SLI), are still sometimes used for calculating nutrient require-ments. Using these will give you somewhat different require-ment figures so it is important that this is borne in mind.

To obtain population nutrient requirements, assumptions haveto be made about the demographic profile of the population,the bioavailability of nutrients within the diet, the energy re-quirement of the population, and allowances made for pop-ulation health status.

Assessing these factors in emergencies is not easy and usuallyimpossible in the early stages of the emergency. The use ofthe population planning figures in indirect assessment of therisk of micronutrient deficiencies is therefore usually essential.Table 4 gives the planning figures for a general food rationthat are designed to meet the needs of a population accordingto Sphere. This planning figure should be revised as necessarybased on an assessment of the demographic structure, activitylevel, ambient temperature, and health status of the pop-ulation (see module 11 for details).

TECHNICAL NOTES



Func

tion

Form

s an

d m

easu

rem

ent u

nits

Sour

ces

Effe

cts

of s

tora

ge a

nd p

repa

ratio

n

Vita

min

A is

a fa

t-so

lubl

e vi

tam

inVi

tam

in A

is p

rese

nt in

food

inRe

tinol

is c

hief

ly fo

und

in d

airy

Both

retin

ol a

nd c

arot

ene

are

stab

le to

requ

ired

for t

he n

orm

al fu

nctio

ning

two

form

s:pr

oduc

ts, l

iver

and

som

e fa

tty

fish.

ordi

nary

coo

king

met

hods

thou

ghof

the

visu

al sy

stem

, gro

wth

and

–Pr

efor

med

vita

min

A (r

etin

ol)

Caro

tene

s are

foun

d in

yel

low

and

som

e lo

sses

may

occ

ur a

tde

velo

pmen

t, m

aint

enan

ce o

fco

ntai

ned

in fo

ods o

f ani

mal

orig

inre

d fru

its a

nd v

eget

able

s, an

d in

tem

pera

ture

s abo

ve 1

00°C

as w

hen

epith

elia

l cel

l int

egrit

y, im

mun

e–

Prov

itam

in A

car

oten

oids

gree

n le

afy

vege

tabl

es, e

spec

ially

butt

er o

r pal

m o

il is

used

for f

ryin

g.fu

nctio

n, a

nd re

prod

uctio

n.(e

.g. b

eta-

caro

tene

) con

tain

ed in

the

gree

n ou

ter l

eave

s. Vi

tam

in A

isVi

tam

in A

is se

nsiti

ve to

oxi

datio

n, so

plan

t foo

dsab

sent

in v

eget

able

oils

with

the

food

s tha

t are

drie

d in

the

sun

lose

Hum

an n

utrit

iona

l req

uire

men

ts a

reex

cept

ion

of fo

rtifi

ed m

arga

rines

muc

h of

thei

r vita

min

A p

oten

cy.

usua

lly e

xpre

ssed

as µ

g of

retin

olan

d re

d pa

lm o

il w

hich

con

tain

Vita

min

A-r

ich

food

s sho

uld

be st

ored

equi

vale

nts (

RE).

Vita

min

A in

prov

itam

in A

.ou

t of d

irect

sunl

ight

.su

pple

men

t cap

sule

s is m

easu

red

inin

tern

atio

nal u

nits

(IU

).1.

0µg

RE =

3.3

IU

Sign

s of

def

icie

ncy

At r

isk

grou

psEf

fect

s of

hig

h in

take

s/to

xici

ty

Vita

min

A d

efic

ienc

y re

sults

in x

erop

htha

lmia

, whi

ch a

ff ect

s the

eye

s.Vi

tam

in A

def

icie

ncy

occu

rs w

idel

yVi

tam

in A

toxi

city

can

be

clas

sifie

dTh

e m

ain

signs

in o

rder

of s

ever

ity a

re:

in d

evel

opin

g co

untr

ies w

ith th

ein

to a

cute

, chr

onic

or t

erat

ogen

ic:

•N

ight

blin

dnes

s (XN

)hi

ghes

t pre

vale

nce

rate

s in

the

–Ac

ute

toxi

city

resu

lts fr

om o

ne o

r•

Bito

t’s sp

ots (

X1B)

Foa

my

accu

mul

atio

ns o

n th

e co

njun

c tiv

a (in

ner e

yelid

s),

regi

ons o

f Sou

th E

ast A

sia a

nd A

frica

.se

vera

l ver

y la

rge

dose

s of

that

ofte

n ap

pear

nea

r the

out

er e

dge

of th

e iri

s.Ch

ildre

n su

fferin

g fro

m m

easle

s,vi

tam

in A

. The

sign

s (vo

miti

ng,

•Co

rnea

l xer

osis

(X2)

Dry

ness

, dul

lnes

s or c

loud

ing

(milk

y ap

pear

ance

) of

diar

rhoe

a, re

spira

tory

infe

ctio

ns,

diar

rhoe

a, b

ulgi

ng fo

ntan

el in

the

corn

ea.

chic

kenp

ox a

nd o

ther

seve

rech

ildre

n, h

eada

ches

) usu

ally

•Ke

rato

mal

acia

(X3)

Sof

teni

ng a

nd u

lcer

atio

n of

the

cor n

ea. T

his i

sin

fect

ions

are

at i

ncre

ased

risk

of

disa

ppea

r afte

r a fe

w d

ays.

som

etim

es fo

llow

ed b

y pe

rfora

tion

of th

e co

rnea

, whi

ch le

ads t

o th

e lo

ssvi

tam

in A

def

icie

ncy.

–Ch

roni

c to

xici

ty o

ccur

s with

of e

ye c

onte

nts a

nd p

erm

anen

t blin

dnes

s. U

lcer

atio

n an

d pe

r fora

tion

may

recu

rrent

exc

essiv

e in

take

s ove

roc

cur a

larm

ingl

y fa

st (w

ithin

a m

att e

r of h

ours

).a

perio

d of

mon

ths t

o ye

ars o

fTh

e le

tter

s and

num

bers

in b

rack

ets,

e.g.

X1B

, are

the

code

s for

the

diffe

rent

exce

ssiv

e do

ses o

f vita

min

A.

form

s of x

erop

htha

lmia

.–

Tera

toge

nic

toxi

city

in p

regn

ant

wom

en m

ay le

ad to

foet

al lo

ss, a

ndVi

tam

in A

def

icie

ncy

in c

hild

ren

is al

so a

ssoc

iate

d w

ith a

n in

crea

sed

risk

and

birt

h de

fect

s. W

omen

who

are

or

seve

rity

of m

orbi

dity

and

incr

ease

d ris

k of

mor

talit

y.m

ay b

ecom

e pr

egna

nt sh

ould

not

cons

ume

mor

e th

an 3

,000

µg R

Epe

r day

.

Tabl

e 3:

Func

tions

, sou

rces

, and

sig

ns o

f def

icie

ncy

for s

elec

ted

mic

ronu

trie

nts

Vitamin A

TECHNICAL NOTES



Func

tion

Form

s an

d m

easu

rem

ent u

nits

Sour

ces

Effe

cts

of s

tora

ge a

nd p

repa

ratio

n

Thia

min

e is

wat

er-s

olub

le v

itam

inTh

iam

ine

(can

also

be

spel

t Thi

amin

)Th

iam

ine

is w

idel

y di

strib

uted

inLa

rge

loss

es o

f thi

amin

e oc

cur d

urin

gth

at fu

nctio

ns a

s a c

oenz

yme

inex

ists i

n on

e m

ain

form

and

hum

anan

imal

and

pla

nt ti

ssue

s. Th

e on

lym

illin

g or

pou

ndin

g w

hen

the

oute

rth

e m

etab

olism

of c

arbo

hydr

ates

nutr

ition

al re

quire

men

ts a

re u

sual

lyric

h so

urce

s, ho

wev

er, a

re li

ver,

laye

r of c

erea

ls is

lost

. Par

boili

ng ri

cean

d br

anch

ed-c

hain

am

ino

acid

s.m

easu

red

in m

illig

ram

s (m

g)ye

ast a

nd le

gum

es.

prio

r to

mill

ing

redu

ces l

osse

s as

thia

min

e is

driv

en in

to th

e in

terio

r of

the

grai

n. T

here

are

loss

es w

hen

cook

ing

wat

er is

disc

arde

d.

Sign

s of

def

icie

ncy

At r

isk

grou

psEf

fect

s of

hig

h in

take

s/to

xici

ty

Thia

min

e de

ficie

ncy

resu

lts in

ber

iber

i. Fo

ur fo

rms o

f ber

iber

i tha

t are

Popu

latio

ns w

ho c

onsu

me

Thia

min

e ha

s a lo

w to

xici

ty a

ndco

mm

only

due

to lo

w in

take

of v

itam

in B

1 in

dev

elop

ing

coun

trie

sno

n-pa

rboi

led

polis

hed

rice

asth

ere

are

no e

stab

lishe

d up

per l

imits

are

desc

ribed

:a

stap

le a

re a

t risk

. Thi

s in

clud

esfo

r int

ake.

1W

et b

erib

eri:

brea

stfe

d ba

bies

who

se m

othe

rs–

Anor

exia

(los

s of a

ppet

ite) a

nd il

l-def

ined

mal

aise

are

eatin

g a

defic

ient

die

t.–

Tend

erne

ss in

the

calf

mus

cles

and

‘pin

s and

nee

dles

’–

Oed

ema

spre

adin

g fro

m le

gs to

the

face

and

trun

kTh

ose

at ri

sk a

lso in

clud

e th

ose

who

–Re

stle

ssne

ss a

nd b

r eat

hles

snes

s with

rapi

d pu

lse a

nd p

alpi

tatio

nsco

nsum

e di

ets r

ich

in a

nti-t

hiam

ine

2D

ry b

erib

eri:

fact

ors,

such

as s

ulph

ites (

adde

d in

–Po

lyne

urop

athy

(gen

eral

dys

func

tion

of th

e ne

rvou

s sys

tem

)fo

od p

roce

ssin

g), r

aw fi

sh a

ndw

ith lo

ss o

f fee

ling

in th

e fe

et a

nd d

imin

ished

t ouc

h se

nsat

ion

shel

lfish

, and

bet

el n

uts.

–M

uscl

es b

ecom

e pr

ogre

ssiv

ely

was

ted

and

wea

k, a

nd w

alki

ngbe

com

es d

iffic

ult

3In

fant

ile a

cute

car

diac

ber

iber

i:–

Peak

pre

vale

nce

in b

reas

t-fe

d ba

bies

of 1

-3 m

onth

s of a

ge.

–Co

lic-li

ke sy

mpt

oms w

ith sc

ream

ing

bout

s, re

stle

ssne

ss,

anor

exia

and

vom

iting

–O

edem

a–

Brea

thle

ssne

ss w

ith si

g ns o

f hea

rt fa

ilure

and

incr

ease

d pu

lse ra

te–

Hea

rt fa

ilure

eve

ntua

lly le

ads t

o de

ath

4Ap

honi

c be

riber

i:–

Peak

pre

vale

nce

in 4

-6 m

onth

old

chi

ldr e

n. V

oice

cha

nges

with

a c

r yth

at b

ecom

es m

ore

and

mor

e ho

arse

unt

il no

soun

d at

all

is pr

oduc

ed.

Rest

less

ness

and

br e

athl

essn

ess,

Oed

ema

Thia

min

e de

ficie

ncy

also

resu

lts in

Wer

nick

e-Ko

rsak

off s

yndr

ome,

a c

ondi

tion

frequ

ently

ass

ocia

ted

with

chr

onic

alc

ohol

ism

Tabl

e 3:

Func

tions

, sou

rces

, and

sig

ns o

f def

icie

ncy

for s

elec

ted

mic

ronu

trie

nts

(con

tinue

d)

Vitamin B1 (Thiamine)

TECHNICAL NOTES



Func

tion

Form

s an

d m

easu

rem

ent u

nits

Sour

ces

Effe

cts

of s

tora

ge a

nd p

repa

ratio

n

Ribo

flavi

n is

a w

ater

-sol

uble

vita

min

Ribo

flavi

n ex

ists i

n on

e m

ain

form

and

Ribo

flavi

n is

wid

ely

dist

ribut

ed in

Ribo

flavi

n is

heat

stab

le b

ut c

an b

ere

quire

d fo

r the

nor

mal

func

tioni

nghu

man

nut

ritio

nal r

equi

rem

ents

are

food

but

is in

low

leve

ls in

mos

t foo

dsle

ache

d ou

t of f

ood

durin

g co

okin

gof

man

y en

zym

es a

s wel

l as t

heus

ually

mea

sure

d in

mill

igra

ms (

mg)

that

are

not

of a

nim

al o

rigin

. Ric

han

d is

sens

itive

to li

ght a

nd a

lkal

ine

deve

lopm

ent a

nd m

aint

enan

ce o

fso

urce

s inc

lude

dai

ry p

rodu

cts,

eggs

,so

lutio

ns.

epith

elia

l cel

l int

egrit

y.le

an m

eats

, and

legu

mes

.

Sign

s of

def

icie

ncy

At r

isk

grou

psEf

fect

s of

hig

h in

take

s/to

xici

ty

Ribo

flavi

n de

ficie

ncy

lead

s to

arib

ofla

vino

sis, a

def

icie

ncy

dise

ase

Popu

latio

ns d

epen

dent

on

rice

as a

Ribo

flavi

n is

wel

l tol

erat

ed a

nd h

asch

arac

teris

ed b

y an

gula

r sto

mat

itis.

stap

le. A

ribof

lavi

nosis

is fo

und

a ve

ry lo

w to

xici

ty.

exte

nsiv

ely

in so

uth

Asia

as w

ell a

s in

Angu

lar s

tom

atiti

s affe

cts t

he c

orne

rs o

f the

mou

th w

hich

can

bec

ome

split

or

part

s of A

frica

. Tho

se w

ho a

re a

t risk

crac

ked.

The

lesio

ns m

ay b

ecom

e in

fect

ed w

ith p

atho

gens

such

as c

andi

daha

ve a

lim

ited

avai

labi

lity

of fo

od in

albi

cans

and

hav

e a

whi

tish

appe

aran

ce.

gene

ral a

nd a

low

con

sum

ptio

n of

dairy

pro

duct

s.Ch

eilo

sis, s

calin

g an

d cr

ack i

ng o

f the

surfa

ce o

f the

lips

ma y

be

seen

.

Glo

ssiti

s, in

flam

mat

ion

or sw

ellin

g of

the

tong

ue is

also

som

etim

es r e

port

ed.

Tabl

e 3:

Func

tions

, sou

rces

, and

sig

ns o

f def

icie

ncy

for s

elec

ted

mic

ronu

trie

nts

(con

tinue

d)Vitamin B2 (Riboflavin)

TECHNICAL NOTES



Func

tion

Form

s an

d m

easu

rem

ent u

nits

Sour

ces

Effe

cts

of s

tora

ge a

nd p

repa

ratio

n

Nia

cin

is w

ater

-sol

uble

and

pla

ysN

iaci

n ex

ists i

n th

e fo

rms o

f nic

otin

icN

iaci

n is

wid

ely

dist

ribut

ed in

pla

ntCo

okin

g ca

uses

litt

le a

ctua

la

cent

ral r

ole

in th

e ut

iliza

tion

ofac

id a

nd n

icot

inam

ide.

It c

an b

ean

d an

imal

food

s, bu

t onl

y in

smal

lde

stru

ctio

n of

nia

cin

but c

onsid

erab

lefo

od e

nerg

y.sy

nthe

sized

from

the

amin

o ac

idam

ount

s, ex

cept

in m

eat (

espe

cial

lyam

ount

s may

be

lost

in th

e co

okin

gtr

ypto

phan

. On

aver

age,

1 m

g of

offa

l), fi

sh, w

hole

mea

l cer

eals

wat

er a

nd ‘d

rippi

ngs’

from

coo

ked

It is

also

kno

wn

as v

itam

in P

Pni

acin

is d

eriv

ed fr

om 6

0 m

g of

die

tary

and

pulse

s.m

eat i

f the

se a

re d

iscar

ded.

(pel

lagr

a pr

even

tativ

e fa

ctor

).tr

ypto

phan

. Nia

cin

is us

ually

mea

sure

das

mill

igra

ms (

mg)

of p

refo

rmed

nia

cin,

or a

s mg

Nia

cin

Equi

vale

nts (

NE)

,w

hich

incl

udes

the

niac

in th

at c

an b

em

ade

by th

e bo

dy fr

om tr

ypto

phan

.AN

E ar

e Av

aila

ble

Nia

cin

Equi

vale

nts

whi

ch a

llow

s for

the

fact

that

nia

cin

from

cer

eal g

rain

s suc

h as

mai

ze h

asa

low

bio

logi

cal a

vaila

bilit

y.

Sign

s of

def

icie

ncy

At r

isk

grou

psEf

fect

s of

hig

h in

take

s/to

xici

ty

Nia

cin

defic

ienc

y re

sults

in p

ella

gra,

whi

ch a

ffect

s the

skin

, gas

tro-

inte

stin

alPo

pula

tions

, who

con

sum

e m

aiz e

as

Hig

h do

ses o

f nic

otin

ic a

cid

can

caus

etr

act a

nd n

ervo

us sy

stem

s. Fo

r thi

s rea

son,

it is

som

etim

es c

alle

d th

e di

seas

eth

eir s

tapl

e w

ithou

t pr o

cess

ing

the

vaso

dila

tatio

n an

d flu

shin

g an

dof

the

3Ds:

derm

atiti

s, di

arrh

oea

and

dem

entia

:m

aize

with

alk

ali t

o re

leas

e ni

acin

,ga

stro

inte

stin

al e

ffect

s suc

h as

–D

erm

atiti

s dev

elop

s as r

edne

ss a

nd it

chin

g on

are

as o

f the

skin

exp

osed

are

at ri

sk o

f dev

elop

ing

pella

gra.

dysp

epsia

, dia

rrho

ea a

ndto

sun

light

cons

tipat

ion.

–Th

e re

dnes

s dev

elop

s int

o a

dist

inct

ive

‘craz

y pa

vem

ent’

patt

ern

and

isPr

oces

sing

mai

ze w

ith a

lkal

i is

sym

met

rical

and

bila

tera

l.co

mm

only

pra

ctic

ed in

Sou

thLo

ng te

rm, v

ery

high

dos

es–

Whe

re d

erm

atiti

s affe

cts t

he n

eck,

it is

som

etim

es te

rmed

‘Cas

al’s

neck

lace

’Am

eric

a bu

t is r

arel

y do

ne in

Afri

ca,

(3-9

g pe

r day

), m

ay re

sult

in–

A di

stin

ctiv

e ‘b

utte

rfly

sign’

arou

nd th

e no

se a

nd e

yes i

s som

etim

es se

enw

here

pel

lagr

a is

ende

mic

.he

pato

toxi

city

.–

Com

plai

nts o

f the

dig

estiv

e sy

stem

incl

uded

dia

rrho

ea, n

ause

a an

dso

met

imes

con

stip

atio

nW

here

nia

cin

rich

food

s, su

ch a

s–

Dist

urba

nces

of t

he n

ervo

us sy

stem

incl

ude

inso

mni

a, a

nxie

t y w

eakn

ess,

pean

uts,

have

not

bee

n pr

ovid

ed in

trem

or, d

epre

ssio

n an

d irr

itabi

lity

emer

genc

y fo

od ra

tions

pel

lagr

a ha

s–

Dem

entia

or d

eliri

um is

som

etim

es se

enoc

curre

d. A

dults

are

at h

ighe

r risk

than

chi

ldre

n an

d w

omen

mor

ePe

llagr

a m

ay b

e fa

tal i

f not

trea

ted,

the

4th

D b

eing

dea

th.

than

men

.

Tabl

e 3:

Func

tions

, sou

rces

, and

sig

ns o

f def

icie

ncy

for s

elec

ted

mic

ronu

trie

nts

(con

tinue

d)

Vitamin B3 (Niacin)

TECHNICAL NOTES



Func

tion

Form

s an

d m

easu

rem

ent u

nits

Sour

ces

Effe

cts

of s

tora

ge a

nd p

repa

ratio

n

Vita

min

C is

wat

er-s

olub

le a

ndVi

tam

in C

is o

ften

calle

d as

corb

ic a

cid.

Vita

min

C is

wid

ely

dist

ribut

ed in

Vita

min

C is

not

ver

y st

able

and

may

play

s a c

ruci

al ro

le in

the

How

ever

, vita

min

C h

as tw

o ch

emic

alpl

ant a

nd a

nim

al fo

ods a

nd is

foun

dbe

oxi

dise

d du

ring

food

stor

age,

mai

nten

ance

of c

onne

ctiv

e tis

sue,

form

s; as

corb

ic a

cid

and

in h

igh

conc

entr

atio

ns in

frui

ts a

ndpr

epar

atio

n, a

nd c

ooki

ng.

supp

orts

imm

une

func

tion,

and

dehy

droa

scor

bic

acid

.ve

geta

bles

, e.g

. gua

va a

nd c

itrus

frui

t.pr

omot

es w

ound

hea

ling.

It a

lsoen

hanc

es th

e ab

sorp

tion

of ir

onH

uman

nut

ritio

nal r

equi

rem

ents

are

in th

e gu

t.us

ually

exp

ress

ed a

s mg

per p

erso

npe

r day

.

Sign

s of

def

icie

ncy

At r

isk

grou

psEf

fect

s of

hig

h in

take

s/to

xici

ty

Clin

ical

vita

min

C d

efic

ienc

y re

sults

in sc

urvy

. Cla

ssic

sign

s inc

lude

:Po

pula

tions

with

a lo

w in

take

of f

resh

Very

hig

h do

ses (

over

200

0mg

in•

Lack

of e

nerg

y, w

eakn

ess,

irrita

bilit

y, an

d w

eigh

t los

sfru

it an

d ve

geta

bles

. In

food

aid

adul

ts) m

ay re

sult

in n

ause

a an

d•

Swol

len

and

blee

ding

gum

sde

pend

ent p

opul

atio

ns fo

rtifi

eddi

arrh

oea,

inte

rfere

with

the

•Pe

rifol

licul

ar h

aem

orrh

ages

blen

ded

food

s may

be

the

only

antio

xida

nt-p

roox

idan

t bal

ance

in th

e•

Brui

sing

sour

ce o

f vita

min

C.

body

, and

, in

patie

nts w

ith•

Skel

etal

cha

nges

in c

hild

ren

thal

asse

mia

or h

emoc

hrom

atos

is,pr

omot

e iro

n ov

erlo

ad.

If le

ft un

treat

ed, S

curv

y ca

n be

fata

l.

Tabl

e 3:

Func

tions

, sou

rces

, and

sig

ns o

f def

icie

ncy

for s

elec

ted

mic

ronu

trie

nts

(con

tinue

d)Vitamin C

TECHNICAL NOTES



Func

tion

Form

s an

d m

easu

rem

ent u

nits

Sour

ces

Effe

cts

of s

tora

ge a

nd p

repa

ratio

n

Vita

min

D is

fat-

solu

ble

and

itsVi

tam

in D

is fo

und

in tw

o fo

rms:

Vita

min

D is

mai

nly

synt

hesiz

ed in

Stor

age,

pro

cess

ing

and

prep

arat

ion

activ

e fo

rm is

invo

lved

in c

alci

um•

Ergo

calc

ifero

l (vi

tam

in D

2)th

e bo

dy w

hen

the

skin

is e

xpos

edha

ve n

o ad

vers

e ef

fect

s on

hom

eost

asis

and

bone

•Ch

olec

alci

fero

l (vi

tam

in D

3)to

sunl

ight

. Oth

er n

atur

al d

ieta

ryvi

tam

in D

con

tent

.m

iner

alisa

tion.

Chol

ecal

cife

rol i

s the

form

nat

ural

lyso

urce

s tha

t may

be

impo

rtan

tm

ade

in th

e hu

man

bod

y.in

clud

e sa

lmon

, sar

dine

s, Tu

na, e

gg,

Requ

irem

ents

for V

itam

in D

are

usu

ally

fish

liver

oil,

mus

hroo

m a

ndex

pres

sed

as µ

g pe

r per

son

per d

ay.

dairy

pro

duct

s.

Sign

s of

def

icie

ncy

At r

isk

grou

psEf

fect

s of

hig

h in

take

s/to

xici

ty

Vita

min

D d

efic

ienc

y re

sults

in ri

cket

s, a

defic

ienc

y di

seas

e th

at a

ffect

s you

ngRi

cket

s is e

ndem

ic in

mos

t Mid

dle

Infa

nts a

re m

ost a

t risk

of d

evel

opin

gch

ildre

n. T

ypic

al si

gns i

nclu

de:

East

ern

coun

trie

s in

a ba

nd g

oing

hype

rvita

min

osis

D. H

yper

calc

aem

ia is

•D

elay

ed c

losu

re o

f fon

tane

lles

from

Mor

occo

to P

akist

an a

nd c

anth

e m

ain

adve

rse

affe

ct a

nd m

ay•

Swol

len

wris

ts a

nd a

nkle

soc

cur a

s far

sout

h as

Eth

iopi

a. It

isre

sult

from

dos

es a

bove

45µ

g pe

r day

.•

Squa

red

head

cau

sed

by b

ossin

g of

fron

tal b

one

stru

ctur

eal

so c

omm

on in

par

ts o

f eas

tern

•Sw

ellin

g of

the

ends

of t

he r i

bs (‘

rach

itic

rosa

ry’)

Euro

pe. L

ack

of e

xpos

ure

to th

e su

n•

Dec

reas

ed m

uscl

e to

nein

com

bina

tion

with

a d

iet l

o w in

•Sp

inal

def

orm

itypr

efor

med

vita

min

D a

nd h

igh

inSe

vere

sign

s inc

lude

:ph

ytic

aci

d (e

.g. b

read

) can

cau

se•

Spon

tane

ous f

ract

ures

ricke

ts. P

opul

atio

ns li

ving

in d

eser

t•

Bow

ing

of le

gsar

eas w

here

atm

osph

eric

dus

t act

s•

Teta

ny (t

witc

hing

in fe

et a

nd h

ands

) and

con

vulsi

ons

as a

filte

r for

ultr

a-vi

olet

ligh

t are

Rach

itic

child

ren

show

redu

ced

bone

gro

wth

, are

ana

emic

, and

pro

ne to

susc

eptib

le, p

artic

ular

ly w

hen

peop

lere

spira

tory

infe

ctio

ns. R

icke

ts m

ay a

lso b

e ca

used

by

calc

ium

def

icie

ncy.

stay

insid

e to

avo

id th

e he

at o

f the

day

and

wea

r ext

ensiv

e cl

othi

ng.

Popu

latio

ns w

ho a

r e fo

rced

to re

mai

nin

side

due

to sh

ellin

g or

figh

ting

are

also

at r

isk.

Tabl

e 3:

Func

tions

, sou

rces

, and

sig

ns o

f def

icie

ncy

for s

elec

ted

mic

ronu

trie

nts

(con

tinue

d)

Vitamin D

TECHNICAL NOTES



Func

tion

Form

s an

d m

easu

rem

ent u

nits

Sour

ces

Effe

cts

of s

tora

ge a

nd p

repa

ratio

n

Iron

has t

hree

maj

or ro

les i

n th

eIro

n is

a ch

emic

al e

lem

ent a

nd is

Mea

t, ce

real

s, ve

geta

bles

and

frui

t all

Iron

is st

able

dur

ing

food

pre

para

tion.

body

. Firs

tly, i

t is n

eces

sary

for t

hefo

und

in tw

o fo

rms i

n fo

od:

cont

ain

iron,

but

hae

m ir

on is

muc

hsy

nthe

sis o

f hae

mog

lobi

n (H

b),

(i)H

eam

iron

: Fou

nd in

ani

mal

sour

cem

ore

easil

y ab

sorb

ed th

an n

on-h

aem

whi

ch c

arrie

s oxy

gen

to th

e bo

dy’s

food

s bou

nd to

hae

m p

rote

in in

iron.

Con

sum

ing

vita

min

C a

t the

cells

and

tran

spor

ts c

arbo

n di

oxid

ebl

ood

and

mus

cle.

sam

e tim

e w

ill in

crea

se a

bsor

ptio

n of

from

the

tissu

es to

the

lung

s.(ii

)Non

-hea

m ir

on: F

ound

mai

nly

iniro

n. E

atin

g ph

ytat

e ric

h fo

ods s

uch

Seco

ndly

, it i

s a c

ompo

nent

of

plan

t foo

ds.

as c

hapa

ttis,

or d

rinki

ng te

a w

hich

myo

glob

in (a

mus

cle

prot

ein)

,H

uman

nut

ritio

nal r

equi

rem

ents

are

cont

ains

pol

y-ph

enol

s, w

ill d

ecre

ase

and

third

ly it

is re

quire

d fo

r the

usua

lly e

xpre

ssed

as m

illig

ram

s (m

g)ab

sorp

tion.

func

tioni

ng o

f man

y en

zym

es.

per d

ay. T

he c

hem

ical

sym

bol f

or ir

onis

Fe a

nd it

exi

sts i

n tw

o io

nic

form

s,as

ferro

us (F

e2+

) and

ferr

ic (F

e3+

) ion

s.

Sign

s of

def

icie

ncy

At r

isk

grou

psEf

fect

s of

hig

h in

take

s/to

xici

ty

Lack

of i

ron

even

tual

ly re

sults

in ir

on-d

efic

ienc

y an

aem

ia. T

ypic

al si

gns a

re:

At ri

sk g

roup

s are

:Th

e ac

ute

toxi

c do

se in

infa

nts i

s•

Pale

con

junc

tivae

(inn

er e

yelid

), na

il be

ds, g

ums,

tong

ue, l

ips a

nd sk

in•

Wom

en o

f chi

ld-b

earin

g ag

eap

prox

imat

ely

20m

g pe

r kg

body

•Ti

redn

ess

(bec

ause

of b

lood

loss

thr o

ugh

wei

ght a

nd th

e le

thal

dos

e is

abou

t•

Hea

dach

esm

enst

ruat

ion)

200-

300m

g pe

r kg.

In a

dults

, a 1

00g

•Br

eath

less

ness

•Pr

egna

nt a

nd b

reas

tfeed

ing

dose

of i

ron

is le

thal

.W

omen

with

seve

re a

naem

ia c

arry

a h

igh

risk

of c

ompl

icat

ions

dur

ing

wom

en (b

ecau

se o

f inc

r eas

ed ir

onch

ildbi

rth.

requ

irem

ents

)•

Babi

es e

xclu

sivel

y br

east

fed

Iron

defic

ienc

y du

ring

infa

ncy

and

early

chi

ldho

od a

lso le

ads t

o im

paire

dbe

yond

the

age

of 6

mon

ths

cogn

itive

dev

elop

men

t. Ec

onom

ic p

rodu

ctiv

ity a

nd e

duca

tiona

l ach

ieve

men

t(b

ecau

se ir

on in

bre

ast m

ilk is

in p

opul

atio

ns is

r edu

ced

by ir

on d

efic

ienc

y an

aem

ia.

inad

equa

te)

•Ba

bies

giv

en c

ow’s

milk

(bec

ause

of in

test

inal

blo

od lo

sses

)•

Wea

ning

-age

chi

ldre

n (b

ecau

seof

inap

prop

riate

wea

ning

die

ts)

•Re

gion

s whe

re m

alar

ia a

ndin

test

inal

par

asiti

c in

f est

atio

n ar

epr

eval

ent a

re a

t risk

.

Tabl

e 3:

Func

tions

, sou

rces

, and

sig

ns o

f def

icie

ncy

for s

elec

ted

mic

ronu

trie

nts

(con

tinue

d)Iron

TECHNICAL NOTES



Func

tion

Form

s an

d m

easu

rem

ent u

nits

Sour

ces

Effe

cts

of s

tora

ge a

nd p

repa

ratio

n

Iodi

ne is

an

esse

ntia

l con

stitu

ent o

fIo

dine

is a

che

mic

al e

lem

ent.

The

leve

l in

the

soil

dete

rmin

es th

eCo

okin

g re

duce

s the

iodi

ne c

onte

nt,

horm

ones

pro

duce

d by

the

thyr

oid

In fo

rtifi

ed sa

lt it

is fo

und

as P

otas

sium

iodi

ne c

onte

nt o

f pla

nts a

nd a

nim

als.

with

abo

ut h

alf b

eing

lost

dur

ing

glan

d in

the

neck

. In

the

foet

us,

Ioda

te o

r Pot

assiu

m Io

dide

.Ar

eas w

here

freq

uent

floo

ding

or

boili

ng b

ut o

nly

abou

t 20%

bei

ng lo

stio

dine

is n

eces

sary

for t

hedr

aina

ge h

as le

ache

d io

dine

from

the

durin

g fry

ing

or g

rillin

g. Io

dise

d sa

ltde

velo

pmen

t of t

he n

ervo

usH

uman

nut

ritio

nal r

equi

rem

ents

are

envi

ronm

ent a

re p

rone

to io

dine

will

lose

its i

odin

e if

left

unco

vere

d or

syst

em.

usua

lly e

xpre

ssed

as µ

g pe

r per

son

defic

ienc

y. Th

e ric

hest

nat

ural

sour

ceex

pose

d to

hea

t.pe

r day

.of

iodi

ne is

seaf

ood.

The

chem

ical

sym

bol f

or io

dine

is I.

Sign

s of

def

icie

ncy

At r

isk

grou

psEf

fect

s of

hig

h in

take

s/to

xici

ty

Iodi

ne d

efic

ienc

y ca

uses

a ra

nge

of a

bnor

mal

ities

incl

udin

g go

itre

(sw

ellin

g of

Goi

tre is

end

emic

in m

any

Hig

h io

dine

inta

kes c

an c

ause

toxi

cth

e th

yroi

d gl

and

in th

e ne

ck) a

nd c

retin

ism, w

hich

occ

urs i

n th

e of

fspr

ing

ofm

ount

aino

us a

reas

of E

urop

e, A

sia,

mod

ular

goi

tre

and

hype

rthy

roid

ism.

wom

en w

ith se

vere

def

icie

ncy.

the

Amer

icas

and

Afri

ca w

here

ther

eIo

dine

indu

ced

hype

rthy

roid

ism (I

IH)

is lim

ited

acce

ss to

seaf

ood

or io

dise

dm

ay b

e a

part

icul

ar p

robl

em in

aG

oitre

:sa

lt. G

oitre

is a

lso a

ssoc

iate

d w

ith th

epo

pula

tion

that

has

bee

n pr

evio

usly

Gra

de 0

No

palp

able

( can

’t fe

el) o

r visi

bly

enla

r ged

thyr

oid

cons

umpt

ion

of g

oitr o

geni

c fo

ods

defic

ient

and

has

hig

h le

vels

of io

dine

Gra

de 1

A p

alpa

ble

but n

ot v

isibl

y en

lar g

ed th

yroi

d w

ith th

e ne

ck in

such

as c

assa

va. T

he p

reva

lenc

e of

intro

duce

d in

to th

eir d

iet.

a no

rmal

pos

ition

goitr

e in

crea

ses w

ith a

ge a

nd r e

ache

sG

rade

2 A

pal

pabl

e an

d vi

sibly

enl

arge

d th

yroi

d w

ith th

e ne

ck in

a n

orm

ala

peak

dur

ing

adol

esce

nce.

Goi

trea

Posit

ion

tend

s to

affe

ct g

irls m

ore

than

boy

san

d w

omen

mor

e th

an m

en b

ecau

seCr

etin

ism:

of in

crea

sed

activ

ity o

f the

thyr

oid

Ther

e ar

e 2

type

s of c

retin

ismgl

and

durin

g pr

egna

ncy.

Neu

rolo

gica

l cre

tinism

:•

Men

tal d

efic

ienc

y•

Dea

f mut

ism•

Spas

ticity

•At

axia

(lac

k of

mus

cula

r coo

r din

atio

n)

Hyp

othy

roid

or m

yxoe

dem

atou

s cre

tinism

:–

Dw

arfis

m–

Hyp

othy

roid

ism (s

mal

l thy

roid

gla

nd)

Tabl

e 3:

Func

tions

, sou

rces

, and

sig

ns o

f def

icie

ncy

for s

elec

ted

mic

ronu

trie

nts

(con

tinue

d)

Iodine

TECHNICAL NOTES



Func

tion

Form

s an

d m

easu

rem

ent u

nits

Sour

ces

Effe

cts

of s

tora

ge a

nd p

repa

ratio

n

Zinc

is a

n es

sent

ial m

iner

al th

at is

Zinc

is a

n el

emen

t tha

t is f

ound

inZi

nc is

foun

d in

a w

ide

varie

ty o

fAs

zin

c is

not a

labi

le a

n el

emen

t and

impo

rtan

t in

imm

unity

and

gro

wth

vario

us c

ompo

unds

.fo

ods w

ith ri

ch so

urce

s inc

ludi

ng re

dis

reta

ined

dur

ing

mos

t for

ms o

f foo

dm

eat,

who

le g

rain

s, eg

gs a

nd n

uts.

stor

age,

pro

cess

ing

and

cook

ing.

Hum

an n

utrit

iona

l req

uire

men

ts a

reus

ually

exp

ress

ed a

s mg

per p

erso

npe

r day

.

The

chem

ical

sym

bol f

or z

inc

is Zn

and

it oc

curs

as

a di

vale

nt io

n, Z

n2+.

Sign

s of

def

icie

ncy

At r

isk

grou

psEf

fect

s of

hig

h in

take

s/to

xici

ty

Zinc

def

icie

ncy

is as

soci

ated

with

no-

spec

ific

signs

such

as g

row

th fa

ilure

,Po

pula

tions

with

low

die

t div

ersit

yH

igh

dose

s of e

lem

enta

l zin

c ra

ngin

gdi

arrh

oea,

and

skin

lesio

ns. D

war

fism

and

hyp

ogon

adism

hav

e be

en sh

own

and

diet

s hig

h in

fibr

e an

d/or

phy

tate

from

100

to 1

50m

g/da

y fo

r pro

long

edto

resu

lt fro

m d

efic

ienc

y.(e

.g. v

eget

aria

ns) a

re a

t risk

of

perio

ds in

terfe

res w

ith c

oppe

rde

ficie

ncy.

Sub-

grou

ps a

t par

ticul

arm

etab

olism

and

cau

ses l

o w b

lood

Asse

ssm

ent o

f zin

c st

atus

in p

opul

atio

ns a

nd in

divi

dual

s rem

ains

ver

y di

fficu

lt.ris

k ar

e in

fant

s, ad

oles

cent

s and

copp

er le

vels,

red

bloo

d ce

llIn

dica

tors

of z

inc

defic

ienc

y re

com

men

ded

by th

e In

tern

atio

nal Z

inc

Nut

r itio

npr

egna

nt w

omen

.m

icro

cyto

sis, n

eutro

peni

a, a

ndCo

nsul

tativ

e G

roup

incl

ude:

the

prev

alen

ce o

f ser

um z

inc

conc

entr

atio

n le

ssim

paire

d im

mun

ity. I

nges

ting

larg

erth

an th

e ag

e/se

x/tim

e of

da y

-spe

cific

cut

-offs

; the

pre

vale

nce

(or p

roba

bilit

y)Pa

tient

s with

gen

etic

dise

ases

such

amou

nts (

200

to 8

00m

g/da

y), e

.g. b

yof

zin

c in

take

s bel

ow th

e ap

prop

riate

est

imat

ed a

vera

ge re

quire

men

t (EA

R);

as a

crod

erm

atiti

s ent

erop

athi

ca a

ndco

nsum

ing

acid

ic f o

od o

r drin

k fro

man

d th

e pr

esen

ce o

f a l

ow h

eigh

t-fo

r-ag

e in

20%

or m

ore

of th

e po

pula

tion.

sickl

e ce

ll an

aem

ia a

re a

t spe

cial

risk

a ga

lvan

ized

(zin

c-co

ated

) con

tain

er,

of z

inc

defic

ienc

y.ca

n ca

use

anor

exia

, vom

iting

,an

d di

arrh

oea.

Tabl

e 3:

Func

tions

, sou

rces

, and

sig

ns o

f def

icie

ncy

for s

elec

ted

mic

ronu

trie

nts

(con

tinue

d)Zinc

TECHNICAL NOTES



The micronutrient content of food aid rations

The micronutrient content of general rations distributed inmany food aid operations has been the subject of criticism fora number of years. Recommended rations generally include acereal, pulses, oil, salt and multi-micronutrient fortified blendedfood.

Fortified blended food has been added to general rations sincethe mid-nineties to improve its micronutrient content. It is alsorecommended by the United Nations High Commissioner forRefugees (UNHCR) and other technical agencies that salt isfortified with iodine, oil with vitamin A and D and wheat andmaize flour with multi-micronutrients. However, analysis of themicronutrient content of standard rations still reveals thepresence of deficiencies in micronutrients.

This problem persists for a number of reasons. Fortification ofthe staple cereal in food aid rations is still uncommon and,where food fortification does happen, the micronutrient mixthat is added is often not appropriately designed to fill thenutrient gaps that exist. Where fortified blended food is in-cluded in general rations it is often included either in low quan-tity or quality and may be inadequate to bring the ration upto standard. Lastly, rations are often supplied in the absenceof any complementary food items such as fresh vegetables orfruit.

A memorandum of understanding (MOU) exists between theWorld Food Programme (WFP) and UNHCR that guides foodaid policy in refugee operations This MOU requires UNHCR tosupply complementary food items where needed. The MOUwas agreed in 2002 and is likely to be revised during 2011.

A MOU (1996) also exists between WFP and UNICEF whichincludes the objectives to “prevent famine-related deaths andmalnutrition including micronutrient deficiencies” and ensure “the provision of a food basket that meets the assessed requirementand is nutritionally balanced and culturally acceptable”.

Despite these agreements between the lead UN agencies,logistic and financial challenges mean that basic rations arelimited, complementary food items are often not supplied, andrations may remain nutritionally inadequate. To illustrate theproblem two rations, recommended in the WFP Food andNutrition Handbook (2005), are analysed in table 5. Both showsevere deficiencies of calcium and riboflavin. The maize basedration is also deficient in vitamin C.

3 Expressed as reference nutrient intakes (RNI) for all nutrients except energy and copper.4 Note that NutVal 2006 and other software tools currently use different population requirement values but future versions are likely to incorporate the values given

in table 4.

Table 4: Current standards for population nutritionalrequirements – to be used for planning purposes in theinitial stage of an emergency

Minimum PopulationNutrient Requirements3, 4

Energy 2,100 kcal

Protein 53g (10% of total energy)

Fat 40g (17% of total energy)

Vitamin A 550µg RAE

Vitamin D 6.1µg

Vitamin E 8.0mg alpha-TE

Vitamin K 48.2µg

Vitamin B1 (Thiamin) 1.1mg

Vitamin B2 (Riboflavin) 1.1mg

Vitamin B3 (Niacin) 13.8mg NE

Vitamin B6 (Pyidoxine) 1.2mg

Vitamin B12 (Cobalamin) 2.2µg

Folate 363µg DFE

Pantothenate 4.6mg

Vitamin C 41.6mg

Iron 32mg

Iodine 138µg

Zinc 12.4mg

Copper 1.1mg

Selenium 27.6µg

Calcium 989mg

Magnesium 201mg

Source: The Sphere Project (2011). Humanitarian Charter and MinimumStandards in Humanitarian Response. Geneva: The Sphere Project.1Alpha-TE – alpha-tocopherol equivalents

RAE – retinol activity equivalents

NE – niacin equivalents

DFE – dietary folate equivalents

TECHNICAL NOTES



Table 5: Examples of typical general rations and micronutrient deficiencies

Maize-based Rice-based

MAIZE GRAIN, WHITE 400g RICE, POLISHED 350g

BEANS, DRIED 60g LENTILS 100g

VEGETABLE OIL 25g VEGETABLE OIL 25g

CORN SOY BLEND 50g CORN SOY BLEND 50g

SUGAR 15g SUGAR 20g

IODISED SALT 5g IODISED SALT 5g

Ration composition is taken from the WFP (2005) Food and Nutrition Handbook. Rome: WFP

The nutrient adequacy was calculated using the NutVal 2006 spreadsheet calculator.

Vitamin Thia- Ribo- VitaminEnergy Protein Fat Calcium Iron Iodine A mine flavin Niacin C

Ration type Kcal g g mg mg µg µg RE mg mg mg mg

Maize-based 99 116 112 45 101 201 95 229 92 126 88

Rice-based 100 117 77 38 97 201 97 116 50 226 110

Nutrient Adequacy (%)

Monitoring ration contents anddietary intakesEven if a general food ration is correctly designed to meet nutri-ent requirements, the ration that is actually received and con-sumed by the population may differ for several reasons:

• The ration actually distributed on a particulardistribution cycle might differ from the planned one forlogistical reasons. For example, some items might bemissing and be replaced (or not) by others.

• At the distribution point, problems in distributionprocedures might mean that people do not receive theintended quantities of the planned ration.

• Food rations are often not entirely used for consumptionbut may be sold or exchanged for different purposessuch as milling cereals, buying fresh foods andcondiments to diversify the diet, buying essentialnon food items. This might be difficult to quantifywith precision.

• The population might consume other foods in additionto the general ration.

• The size and structure of the beneficiary population maychange due to in or out migration, births, or mortality,making the planning figures obsolete.

Good data on the functioning of a food aid system is essentialfor monitoring the risk of MDD. See figure 1. Assuming thatthe ration has been planned and assessed to be adequate,the three components of a good food aid monitoring systemwill usually include:

1 monitoring of the food aid logistics chain anddistribution process

2 on-site distribution monitoring (OSDM) also sometimescalled food basket monitoring and

3 post-distribution monitoring (PDM) at the householdand market level.

All of these stages are necessary for adequate indirect assess-ment of the risk of micronutrient malnutrition.

The aim of OSDM is to compare the food actually received byfamilies with the planned ration and to follow-up on anyshortfall reported. Protocols for OSDM are laid out in MedecinSans Frontieres (MSF) and UNHCR Guidelines. It is good prac-tice for the agency doing the OSDM to be organisationallyseparate from that involved in food distribution to avoid anyconflict of interest that might arise. Criteria for the interpreta-tion of OSDM data have been laid down by UNHCR. Accordingto the UNHCR guidelines, the cut-offs for acceptable distribu-tions are < 90 per cent or >110 per cent of the planned kcal/person/day. While this is a useful criterion, it takes no accountof differences that may be found in the distribution of differentcommodities and the impact on the micronutrient sufficiencyof the ration.

TECHNICAL NOTES



Report on Nutrition Survey and an Investigation of the Underlying Causes Of Malnutrition. Camps for Myanmar Refugees from Northern Rakhine State Cox’s Bazar, Bangladesh,August 2003. UNHCR

Since 1978, refugees from Northern Rakhine State, Myanmar, have been living in camps in the Cox’s Bazar area of Bang-ladesh. Nutrition survey data was compiled in 2003 and showed that angular stomatitis, a clinical sign of ariboflavinosis,had been prevalent in children (6-59 months) since at least 1997. In 5 surveys conducted between 1997 and 2003 theprevalence of angular stomatitis varied from 7.0 to 12.6%, indicating chronic riboflavin deficiency.

Analysis of the on-site distribution survey (also called food basket monitoring) data showed that the general rationreceived during 2002 and the first half of 2003 contained an average of only 33% of the population requirement forriboflavin.

Despite the availability of this data no measures were taken at that time to improve the nutrient adequacy of the generalration. However, more recently micronutrient powders and other specialised food supplementation products have beenpiloted in these camps. See module 14 for more information on interventions for micronutrient malnutrition.

Case example 1: Inadequate general rations associated with persistent angular stomatitis in refugees in Bangladesh: 2003

5 NutVal can be downloaded free of charge from http://www.ucl.ac.uk/cihd/6 See INFOODS for a list of software products http://www.fao.org/infoods/software_en.stm

In these methods the survey subjects are asked whether theyhave consumed a specific food item or food group, typicallywithin the last 24 hours or seven days. While it is not possibleto calculate the actual quantities consumed, the diet diversityscore or food variety score approach may be useful for under-standing the sources of micronutrient-rich foods in the dietand for monitoring access to different foods over time.

When food aid is not intended to cover the full needs of thepopulation, a significant amount of micronutrients mightcome from other sources of food. In this case, it might be diffi-cult to find out what these other sources are and in what quan-tities they are being consumed.

When using indirect assessment for population subgroups,certain practical problems may occur. For example, althoughthe RNI are given for different age and gender groups thesemay not always correspond to the groups that are beingassessed.

A variety of software tools have been designed for calculatingthe nutrient content of food aid rations. The most well knowninclude NutCalc, which was developed by EpiCentre for ActionContre le Faim, and NutVal, which was developed for UNHCRand WFP by the University College London Centre for Inter-national Health and Development.5 Many other software pro-ducts for the calculation of nutrient content exist but thesetend not to be specialised for food aid operations.6

NutVal 2006 is currently recommended by WFP and UNHCRfor use in planning and monitoring food aid rations.

Exercises included in part 3 of this module demonstrate theuse of manual calculation and NutVal software for workingout the micronutrient composition of food aid rations.

Post Distribution Monitoring (PDM) should usually be conduct-ed some time after the distribution (roughly 10-20 days afterthe distribution if the distributions are done on a monthlybasis). The PDM looks at the use of the ration and the adequacyof the distribution system. In general, the scope of PDM is quitebroad and includes other relevant food security information.

In many food aid operations the recipient populations are onlypartially dependent on food aid and may have access to a widerange of other commodities. While determining what thesefoods are may be relatively straightforward, gaining an accurateassessment of the quantities available and consumed oftenproves extremely difficult. The various food security methodsthat exist are very valuable for gaining in depth insight intohousehold economies but are somewhat cumbersome to useto try and quantify the risk of micronutrient deficiencies.

Intra household distribution of food is another critical factorthat may affect the risk of certain population groups develop-ing deficiencies. Food distribution practices are often deeplyentrenched in cultural norms and traditions.

RThe accurate measurement of dietary nutrient intake usingweighed intakes, portion sizes or other methods is a challen-ging undertaking in any setting. Such approaches are usuallyinappropriate in refugee or emergency assessments althoughthey have been used in research studies. The measurement ofa diet diversity score or food variety score using food frequencyquestionnaires is, in contrast, a much simpler and more robusttechnique. The resulting scores have been shown to correlatewith anthropometric status and haemoglobin concentration.

TECHNICAL NOTES



Assessment ofAdequacy

Figure 1: Monitoring points in a food aid system

Commodity sourcing/transport/storage

Utilisation bybeneficiariesRation Planning Distribution

LogisticMonitoring

Food BasketMonitoring

Post-DistributionMonitoring

Anecdotal reports indicate that ration monitoring by itself is arather blunt tool for predicting the risk of MDD outbreaks, part-ly because a population’s access to alternative diets may beunderestimated.

In contrast, examples of the chronic persistence of seriouslydeficient diets together with direct evidence of clinical defi-ciency are also found. For example, in refugee camps in Bangla-desh, food aid rations have been deficient in riboflavin for yearsand there is an associated high prevalence of angular stomatitis– a clear clinical indicator of riboflavin deficiency. Clearly, theevidence from the indirect assessment of the risk of micro-nutrient deficiencies may not always be effective in producingthe necessary changes in food aid programmes.

Direct assessment: Measurement ofmicronutrient deficiencies in individualsand populationsThere are two main approaches that can be used in direct as-sessment of micronutrient deficiencies:

1. Clinical signs and symptoms

2. Biochemical testing

Each approach has potential advantages and disadvantageswhen considered for use in an emergency context.

Clinical signs and symptoms

Observation of clinical signs or the use of questionnaires toidentify symptoms has the advantage of being non-invasive,usually low cost, and is often the most logistically feasible op-tion in remote areas. Clinical signs continue to be used in nutri-tion surveys to try and obtain a prevalence measure of clinicaldeficiency. By definition, the use of clinical signs cannot tell usabout the prevalence of sub-clinical deficiency and the detec-tion of a clinical case usually represents the tip of the icebergof the deficiency problem. See figure 2.

Figure 2: Schematic representation of how clinical and sub-clinical micronutrient deficiency is distributed in a population

Clinical Deficiency

Biochemical Deficiency

At risk

0.3%

29%

The percentage of women affected by pellagra and niacin deficiency is shown as an example.

This data was collected during a survey in the Kuito area of central Angola in 2004.7

7 Seal, AJ. et al. (2007) Low and deficient niacin status and pellagra are endemic in postwar Angola. Am J Clin Nutr 85: 218-224.

TECHNICAL NOTES



8 Sensitivity is the ability of a test method to detect cases of a disease in people who do actually have the disease. Specificity is the ability of a test method to showa negative result in people without the disease.

An important distinction is between the use of clinical signsand symptoms. Clinical signs are pathological changes thatcan be observed by the surveyor or medical practitioner. Thesubject may or may not be aware of the presence of clinicalsigns. Symptoms are changes that are apparent to the patientor subject but may not always be observable by others. There-fore, in survey work clinical signs rather than symptoms arealmost always used. The use of carer or self reported nightblindness, as an indicator of vitamin A deficiency, is one notableexception.

While clinical signs are very useful they are, with a fewexceptions, often quite non-specific. Goitre is a good exampleof a specific clinical sign of iodine deficiency but even then,goitre may actually result from iodine excess or some otherdisease process, rather than iodine deficiency. Angular stoma-titis is often considered as a specific sign for riboflavin defi-ciency but in fact is associated with at least three nutrientdeficiencies (riboflavin, vitamin B6 and zinc). Nonetheless, thesensitivity and specificity is adequate to make such signs ex-tremely useful for inclusion in surveys.8

Clinical signs are often used in outbreak investigations suchas of scurvy in Afghanistan and pellagra in Angola. Nutritionsurveys quite frequently report the use of clinical signs in ass-essment of deficiencies. Recent examples include surveys ofgoitre in Ivory Coast, and Bitot’s Spots for vitamin A deficiencyin Darfur.

Training staff in correct diagnosis of clinical signs is sometimeschallenging and the use of medically qualified staff is recom-mended whenever possible.

Angular stomatitis is a clinical sign of riboflavin deficiency. It has been measured in nutritional surveys of Bhutaneserefugees living in Nepal camps for a number of years. A nutritional survey conducted in January 2007 found a prevalenceof 1.0% (95% CI 0.4-2.3). The prevalence of this clinical sign had markedly decreased from about 40% in 2000. This mayreflect improvements in the general ration due to the inclusion of blended food and other initiatives. However, thesurvey had been conducted during a different season to the previous one. This made interpretation difficult as theimprovement may just reflect seasonal differences in food availability.http://www.unscn.org/layout/modules/resources/files/NICS_No_13.pdf

Night blindness is a clinical sign of vitamin A deficiency. A survey conducted in the eight most vulnerable areas of Bahjangdistrict, Nepal, in December 2006 measured night blindness in children and their mothers. The reported prevalence was0.5% in children and 15.4% in mothers. The public health significance of this indicator should be assessed in children(preferably between 24-71 months). The prevalence measured indicates a mild public health problem in this situation(see Annex 3 of this module)http://www.unscn.org/layout/modules/resources/files/NICS_No_13.pdf

Box 1: Examples of the use of clinical signs in surveys

When conducting surveys of micronutrient deficiency disea-ses, a clear and simple case definition is essential and the abilityof the survey staff to reliably identity cases should be assessed.For example, pellagra can be assessed using the case definition‘presence of bilateral, symmetrical dermatitis on one or moresun exposed areas of the skin’. Different degrees of vitamin Adeficiency in young children can be assessed using the casedefinitions ‘presence of night blindness’ ‘presence of Bitot’sspots’ ‘presence of corneal xerosis, ulceration or keratomalacia’,‘presence of corneal scars’.

Careful training is essential and where rare conditions are beingsurveyed it is advisable for the survey supervisor to revisit allsuspected cases to confirm the diagnosis. It may be the casethat an adequate case definition cannot be established withthe use of clinical signs by themselves and cut-off values frombiochemical testing may form an important part or the wholeof the case definition.

Biochemical tests

Biochemical tests have the advantage of providing objectivemeasures of micronutrient status. A classification of the differ-ent types of biochemical tests is given in box 2.

The collection of biological samples for testing often presentslogistic, staff training, cold chain, and sometimes, acceptabilitychallenges. Biochemical measurements are also not always asclear-cut, i.e. as sensitive and specific, as might be imagined.Individuals have a wide range of normal values and there arelarge differences between the average values of differenthealthy individuals. There also may be variations according tothe time of day the sample is collected.

TECHNICAL NOTES



Adapted from: Sauberlich, H.E. (1999) Laboratory Tests for the Assessment of Nutritional Status. CRC Press

1. Static measurements of nutrient under study in blood, urine, or other biological sample (e.g. serum retinol)

2. Measurement of a nutrient metabolite, (e.g. N-methylnicotinamide in urine as an indicator of Niacin status)

3. Biochemical functional test (e.g. enzyme activity in red blood cells for vitamins B1 and B2)

4. Presence of abnormal metabolites (e.g. homocysteine for folate deficiency)

5. Product of nutrient under study (e.g. haemoglobin concentration for iron status)

6. Load or saturation test (e.g. vitamin C in urine after consumption of a high dose tablet)

7. Other procedures (e.g. use of stable isotopes)

Box 2: Types of biochemical tests for detecting nutritional deficiencies

As with all assessment methods, care needs to be taken in in-terpreting results obtained at different times of the year. Theremay be normal fluctuations in micronutrient status due to theaffects of the seasons on food availability and/or infections.For example, it has been shown that the vitamin A status ofpeople in the Gambia varies depending on whether samplesare collected during the wet or dry seasons.

Furthermore, different laboratories may produce results thatdo not agree well. Good quality assurance and quality controltesting is essential and should always be considered whenselecting a laboratory for sample testing.

We also need to be aware that a number of different bioche-mical tests may be available for the same micronutrient, andthese may not necessarily give comparable answers. Forexample, iron status may be quantified by measuring a numberof different components including serum ferritin, serum trans-ferrin receptor, zinc protophorphyrin, and transferrin saturation.At the population level it may also be estimated from haemo-globin concentration. However, each of these measures isfocused on a different part of the iron metabolic pathway so itshould be no surprise that different estimates of deficiencymay be obtained when using these different tests with thesame samples. Again, standardisation of methodologies andcut-off values is essential to allow valid comparisons betweensurveys or studies.

Biochemical measurements might sometimes only give partof an answer. For example, low haemoglobin blood concent-ration indicates anaemia. However, anaemia might be relatedto iron deficiency or to infections, especially malaria or hook-worm, which causes a reduction in haemoglobin blood con-centration, or to inherited conditions such as sickle cell anae-mia or thalassaemia.

Finally, for some of the micronutrients, published methods mayprove very difficult to apply in field based surveys, e.g. becauseof contamination in trace element analysis or the requirementfor extended sample collection time.

In conclusion, before embarking on an assessment involvingbiochemical testing it should be understood that the resultsobtained should not always be regarded as definitive, but theycan provide an invaluable additional tool in reaching conclu-sions. Table 6 provides examples of recent studies where bio-chemical measurements have been taken. A summary of teststhat may be considered for inclusion in surveys is included inAnnex 2.

Operational organizations are, in general, becoming moreaware of the importance of micronutrient malnutrition. Forexample, UNHCR has integrated haemoglobin measurementinto routine nutrition surveys in a number of camps, particu-larly in Tanzania, Algeria and Kenya. Data from these periodicsurveys is used for nutritional surveillance.

Challenge 1: Biochemical assessment in people with infections

When people have an infection, the body launches an acute phase response in which the levels of protein production changeand the concentration of circulating nutrients in the blood is altered. This response may help the body in combating theinfection and is a normal physiological response to inflammation. However, it does mean that if certain indicators of nutritionalstatus are measured in a person with infection they will appear to have a worse nutritional status than they actually do. Thisapplies in particular to serum retinol and ferritin, two popular indicators of vitamin A and iron status. Measurement of acutephase proteins, which are markers of inflammation, can allow for adjustment of the measured nutrient indicators, but there isnot yet a widespread consensus on how adjustments should be applied.

TECHNICAL NOTES



Table 6: Recent examples of field studies using biochemical testing

Survey or Study Location Nutrient Test

Kassim et al. (2010)9 Kenya – refugees Iodine Urinary iodine excretionfrom Somalia

Seal et al. (2006)10 Angola – post conflict Niacin Urine excretion ofresident population N-methyl nicotinamide

and 2-pyridone

Bennett and Coninx (2005)11 East Africa – prisoners Vitamin C Serum ascorbic acid

Seal et al. (2005)12 Africa – refugees Vitamin A and iron Serum retinol,from various countries Haemoglobin and sTfR

Kemmer et al. (2003)13 Thailand – refugees Iron Haemoglobin andfrom Myanmar zinc protoporphyrin

McGready (2003)14 Thailand – Karen refugees Thiamine and vitamin A ETKAC,breast milk retinol

Blanck et al. (2002)15 Nepal – refugees Riboflavin EGRACfrom Bhutan

9 Kassim, IAR. et al. (2010) Excessive iodine intake during pregnancy in Somali refugees Maternal and Child Nutrition DOI: 10.1111/j.1740-8709.2010.00259.10 Seal AJ. et al. (2007) Low and deficient niacin status and pellagra are endemic in postwar Angola. Am J Clin Nutr. 85 (1): 218-2411 Bennett, M. & Coninx, R. (2005) The mystery of the wooden leg: vitamin C deficiency in East African prisons. Trop.Doct. 35: 81-84.12 Seal A.J. et al (2005) Iron and vitamin A deficiency in long-term African refugees. J Nutr. 135: 808-1313 Kemmer T.M. et al (2003) Iron deficiency is unacceptably high in refugee children from Burma. J Nutr. 133: 4143-914 McGready, R. et al (2003) Delayed visual maturation in Karen refugee infants. Ann.Trop.Paediatr. 23: 193-204.15 Blanck, H. M. t al (2002) Angular stomatitis and riboflavin status among adolescent Bhutanese refugees living in southeastern Nepal. Am.J.Clin.Nutr. 76: 430-435.

• Safety lancets with automatically self-retracting bladesminimise the risk of needle stick injuries and makes reuseand cross-contamination impossible. If venous samplingis strictly necessary then vacuum loaded blood tubescan ease the collection process and a good quality,disposable, sharps collection box permits storage andtransport of waste between survey sites.

• If surveys are being conducted at the household levelthen care must be taken not to contaminate any itemswith blood, remove any waste, and leave the house as itwas found. While sticking plasters should be appliedafter any incisions it is good practice not to use‘child-friendly’ plasters with pictures of animals orthe like, as these may end up being popular andswappable items!

• Disposable or washable plastic cups should be used forurine collection and disposable plastic tubes for faecalsamples. Medical plastic gloves for sample collectorsoften end up comprising the heaviest items in thesurvey supplies list and these and other items may needto be sourced from national or international suppliersa long way distant from the survey site. Good planningand use of a detailed inventory is essential!

Before deciding to use biochemical sampling as a tool in nu-tritional surveys there are a number of important considera-tions to take into account. The points below do not comprisea manual for how-to-do-it but may help to indicate a few ofthe challenges and potential pitfalls.

• Employing the use of good training and technique,and following universal safety precautions helps tominimise the risk of cross-infection with pathogenssuch as HIV and Hepatitis B. Any potential benefits ofconducting the survey need to be balanced againstthe risks to participants and staff. Survey participantsneed to be given full and honest information aboutthe objectives and methods of the survey and informedconsent must be obtained and documented.

• Selection of sampling method and equipment cangreatly reduce the risk and discomfort for both parties.If at all possible, capillary blood collection should beused instead of venous sampling and the samplecollected straight into a specialised tube withthe appropriate anticoagulant or serum separator gel.

TECHNICAL NOTES



ConclusionsTools for assessing micronutrient status in emergencies areavailable for both indirect and direct assessment approaches.However, there are a number of challenges that limit their im-plementation in the field and careful selection and use is re-quired.

For indirect assessment, it is important to try and gain an un-derstanding of the total dietary intake of micronutrients. Foreffective monitoring of the contribution provided by food aidit is essential to assess the planned ration, the delivery of theplanned ration through the logistics chain, receipt of the rationthrough onsite distribution monitoring, and the use of the ra-tion through post-distribution monitoring.

Direct assessment of micronutrient malnutrition depends onlooking for clinical signs of deficiencies or taking a blood orurine sample for biochemical analysis.

Staff can be trained to recognise the common clinical signs ofmicronutrient deficiency disease by the use of photo-cards.This approach is relatively fast and has a low cost. However,clinical signs are not always specific.

Further improvements in field friendly techniques for thebiochemical assessment of deficiencies are needed. With theexception of the HemoCue photometer, used for the mea-surement of haemoglobin in a finger prick blood sample,collection of biological samples for the analysis of micronu-trients remains challenging. Whilst some techniques have beendeveloped using dried blood spots, direct collection and sto-rage of liquid serum and urine remain a more reliable methodof sample collection. More work on sample collection and sto-rage methods is required to make field surveys easier to con-duct in remote locations.

Information on actual or potential micronutrient malnutritionshould always be crosschecked against other available datato try and obtain the most accurate picture of what is happe-ning.

Micronutrient malnutrition remains a major public health issuethat is far from being eliminated.

• Sample preservation before and during transport/oranalysis is often challenging. Supplies of ice or dry ice areusually required but may be difficult to source. Fridgesand freezers may work intermittently and extra fuel mayneed to be purchased, or solar power laid on to keepthem going constantly without interruption during theduration of the survey. The use of dried blood spots,where a spot of blood is dried onto filter paper and thentransported in a normal envelope provides a, potentially,much simpler solution for sample storage. But cautionis advised unless studies have already been performedto show that the results obtained from samples storedin this way are comparable with results fromliquid samples.

• Finally, formal ethical clearance may be required fromnational and/or international bodies and obtaining thenecessary paperwork may be a time consuming process.

Selection of appropriate population groupsand methods for surveys ofmicronutrient malnutrition

In some situations the careful documentation of individualcase studies may be powerful and sufficient evidence to advo-cate for intervention, especially where the condition is rare,such as for scurvy or pellagra. However, quantification at thepopulation level is often required.

In deciding on a method for assessment of a suspected micro-nutrient problem it is critical to select the appropriate pop-ulation group for study. Table 6 gives guidance on whichgroups to select to gain the most useful indicator. This dependson the relative susceptibility of different age and gendergroups and the availability of assessment methods.

The sample size required for micronutrient surveys is typicallyvery large where clinical signs are used but a lot smaller wherebiochemical measurements are taken. This reflects the relativerarity of overt clinical cases compared to the more prevalentsub-clinical biochemical deficiency that is usually encountered.

Sampling methods may utilise a number of different tech-niques depending on the target population but cluster sam-pling using probability proportional to size will frequently beappropriate and may allow integration with a standard nutri-tion survey (see module 7 for more details about nutrition sur-veys). However, it is important to note that the population sub-group and the required sample size will usually be differentthan that required for a standard anthropometric nutritionsurvey.

Surveillance systems are an alternative to conducting surveysand if micronutrient deficiencies, assessed using either bio-chemical tests or clinical signs, are effectively integrated intoa health information system, monitoring may be relatively lowcost and reliable.

TECHNICAL NOTES



Annex 1: Recommended nutrient intakes by population groupSource: WHO/FAO (2004): Vitamin and mineral requirements in human nutrition, Second edition: WHO: Geneva

Recommended nutrient intakesa – minerals

Zincc (mg/day)

Calciumb Selenium Magnesium High bio- Moderate bio- Low bio-Group (mg/day) (mg/day) (mg/day) availability availability availability

Infants 300d 26d

0-6 months 400g 6 36h 1.1d 2.8 6.6

7-12 months 400 10 54 0.8d 4.1 8.42.5j

Children1-3 years 500 17 60 2.4 4.1 8.3

4-6 years 600 22 76 2.9 4.8 9.6

7-9 years 700 21 100 3.3 5.6 11.2

AdolescentsFemales 10-18 years 1300k 26 220 4.3 7.2 14.4

Males 10-18 years 1300k 32 230 5.1 8.6 17.1

AdultsFemales 19-50 years 1000 26 220 3.0 4.9 9.8(premenopausal)

Females 51-65 years 1300 26 220 3.0 4.9 9.8(menopausal)

Males 19-65 years 1000 34 260 4.2 7.0 14.0

ElderlyFemales 65+ years 1300 25 190 3.0 4.9 9.8

Males 65+ years 1300 33 224 4.2 7.0 14.0

Pregnant womenFirst trimester m m 220 3.4 5.5 11.0

Second trimester m 28 220 4.2 7.0 14.0

Third trimester 1200 30 220 6.0 10.0 20.0

Lactating women0-3 months 1000 35 270 5.8 9.5 19.0

3-6 months 1000 35 270 5.3 8.8 17.5

7-12 months 1000 42 270 4.3 7.2 14.4

a Recommended nutrient intake (RNI) is the daily intake which meets the nutrient requirements of almost all (97.5%) apparently healthy individuals in an age-and sex-specific population.

b For details, see chapter 4 in WHO/FAO (2004): Vitamin and mineral requirements in human nutrition, Second edition: WHO: Geneva.c For details, see chapter 12 in WHO/FAO (2004): Vitamin and mineral requirements in human nutrition, Second edition: WHO: Geneva.d Breastfed.e Neonatal iron stores are sufficient to meet the iron requirement for the first 6 months in full-term infants. Premature infants and low birth weight infants require

additional iron.f Recommendation for the age group 0-4.9 years.g Cow milk-fed.h Formula-fed.

TECHNICAL NOTES



Iron (mg/day)

15% Bioavailability 12% Bioavailability 10% Bioavailability 5% Bioavailability Iodine (µg/day)

e e e e 90f

6.2i 7.7i 9.3i 18.6i 90f

3.9 4.8 5.8 11.6 90f

4.2 5.3 6.3 12.6 90f

5.9 7.4 8.9 17.8 120 (6-12yrs)

9.3 (11-14yrs)l 11.7 (11-14yrs)l 14.0 (11-14yrs)l 28.0 (11-14yrs)l 150 (13-18yrs)

21.8 (11-14yrs) 27.7 (11-14yrs) 32.7 (11-14yrs) 65.4 (11-14yrs)

20.7 (15-17yrs) 25.8 (15-17yrs) 31.0 (15-17yrs) 62.0 (15-17yrs)

9.7 (11-14yrs) 12.2 (11-14yrs) 14.6 (11-14yrs) 29.2 (11-14yrs) 150 (13-18yrs)

12.5 (15-17yrs) 15.7 (15-17yrs) 18.8 (15-17yrs) 37.6 (15-17yrs)

19.6 24.5 29.4 58.8 150

7.5 9.4 11.3 22.6 150

9.1 11.4 13.7 27.4 150

7.5 9.4 11.3 22.6 150

9.1 11.4 13.7 27.4 150

n n n n 200

n n n n 200

n n n n 200

10.0 12.5 15.0 30.0 200

10.0 12.5 15.0 30.0 200

10.0 12.5 15.0 30.0 200i Bioavailability of dietary iron during this period varies greatly.j Not applicable to infants exclusively breastfed.k Particularly during the growth spurt.l Pre-menarche.m Not specified.n It is recommended that iron supplements in tablet form be given to all pregnant women because of the difficulties in correctly assessing iron status in pregnancy.

TECHNICAL NOTES



Recommended nutrient intakesa – water and fat-soluble vitamins

Water-soluble vitamins

Vitamin Cb Thiamine Riboflavin Niacinc Vitamin B6 PantothenateGroup (mg/day) (mg/day) (mg/day) (mg NE/day) (mg/day) (mg/day)

Infants0-6 months 25 0.2 0.3 2i 0.1 1.7

7-12 months 30 0.3 0.4 4 0.3 1.8

Children1-3 years 30 0.5 0.5 6 0.5 2.0

4-6 years 30 0.6 0.6 8 0.6 3.0

7-9 years 35 0.9 0.9 12 1.0 4.0

AdolescentsFemales 10-18 years 40 1.1 1.0 16 1.2 5.0

Males 10-18 years 40 1.2 1.3 16 1.3 5.0

AdultsFemales 19-50 years 45 1.1 1.1 14 1.3 5.0(premenopausal)

Females 51-65 years 45 1.1 1.1 14 1.5 5.0(menopausal)

Males 19-65 years 45 1.2 1.3 16 1.3 (19-50yrs) 5.01.7 (50+yrs)

ElderlyFemales 65+years 45 1.1 1.1 14 1.5 5.0

Males 65+years 45 1.2 1.3 16 1.7 5.0

Pregnant women 55 1.4 1.4 18 1.9 6.0

Lactating women 70 1.5 1.6 17 2.0 7.0

a Recommended nutrient intake (RNI) is the daily intake which meets the nutrient requirements of almost all (97.5%) apparently healthy individuals in an age- andsex-specific population.

b For details, see chapter 7 in WHO/FAO (2004): Vitamin and mineral requirements in human nutrition, Second edition: WHO: Geneva.c NE = Niacin equivalents.d DFE = Dietary folate equivalents; µg of DFE provided = [µg of food folate + (1.7 x µg of synthetic folic acid)].e Vitamin A values are “recommended safe intakes” instead of RNIs. For details, see chapter 2 in WHO/FAO (2004): Vitamin and mineral requirements in human

nutrition, Second edition: WHO: Geneva.f Recommended safe intakes as mg retinol equivalent (RE)/day; conversion factors are as follows:

1µg retinol = 1 RE1µg b-carotene = 0.167µg RE1µg other provitamin A carotenoids = 0.084µg RE.

TECHNICAL NOTES



Water-soluble vitamins Fat-soluble vitamins

Biotin Vitamin B12 Folated Vitamin Ae,f Vitamin D Vitamin Eg Vitamin Kh

(µg/day) (µg/day) (µg DFE/day) (µg RE/day) (µg/day) (mg alpha-TE/day) (µg/day)

5 0.4 80 375 5 2.7j 5k

6 0.7 80 400 5 2.7j 10

8 0.9 150 400 5 5.0j 15

12 1.2 200 450 5 5.0j 20

20 1.8 300 500 5 7.0j 25

25 2.4 400 600 5 7.5 35-55

25 2.4 400 600 5 10.0 35-55

30 2.4 400 500 5 7.5 55

30 2.4 400 500 10 7.5 55

30 2.4 400 600 5 (19-50yrs) 10.0 6510 (51-65yrs)

2.4 400 600 15 7.5 55

l 2.4 400 600 15 10.0 65

30 2.6 600 800 5 j 55

35 2.8 500 850 5 j 55g Data were not strong enough to formulate recommendations. The figures in the table therefore represent the best estimate of requirements.h For details, see chapter 6 in WHO/FAO (2004): Vitamin and mineral requirements in human nutrition, Second edition: WHO: Geneva.i Preformed niacin.j For details, see chapter 5 in WHO/FAO (2004): Vitamin and mineral requirements in human nutrition, Second edition: WHO: Geneva.k This intake cannot be met by infants who are exclusively breastfed. To prevent bleeding due to vitamin K deficiency, all breast-fed infants should receive vitamin K

supplementation at birth according to nationally approved guidelines.l Not specified.

TECHNICAL NOTES



Annex 2: Biochemical tests for anaemia and selected nutrient deficiencies

Available Options Recommended Rational

Anaemia 1 Haemoglobin (Hb) Haemoglobin Haemoglobin concentration is a direct2 Haematocrit measure of anaemia. Using a field photo-

meter such as the Hemocue, measures arequick, easy, and can be carried out athousehold level during surveys.

Iron 1 Serum tranferrin receptors (sTfR) sTfR sTfR is affected little by concurrent2 Ferritin infections and is a widely used measure of3 Serum iron iron deficiency. Measurements can be4 Transferrin saturation made on serum samples prepared from a5 Erythrocyte protoporphyrin finger stick capillary blood sample. If ferritin

is used the values obtained have to becontrolled for inflammation status.

Iodine 1 Urinary iodine Urinary Iodine Single samples of urine can be easily2 Neonatal TSH collected from school aged children or3 Thyroglobulin adult women. Samples are stable and it is

not essential to freeze them during tran-sport. Calculation of the median urinaryexcretion is widely accepted as a validmethod of measuring population status.

Vitamin A 1 Serum retinol Serum retinol Serum retinol concentration is a good(Retinol) 2 Retinol binding protein indicator of vitamin A status in populations

3 Relative dose response tests Measurements can be made on serumsamples prepared from a finger stickcapillary blood sample. Samples from thesame finger stick can be used for both ironand vitamin A measurements.

Vitamin B1 1 Erythrocyte Transketolase Activity All methods have The ETKAC assay measures the activity of(Thiamine) Coefficient (ETKAC) disadvantages an enzyme that is dependent on thiamine.

2 Blood concentration of thiamine but ETKAC is A well accepted functional measurement3 Urine excretion generally but requires the collection, centrifugation

regarded as the and freezing of venous blood samples.most validmeasure of status.

Vitamin B2 1 Erythrocyte Glutathione Reductase Both methods The EGRAC assay measures the activity of(Riboflavin) Activity Coefficient (EGRAC) have an enzyme that is dependent on riboflavin.

2 Blood concentration of riboflavin disadvantages A well accepted functional measurementbut have been but requires the collection, centrifugationused successfully and freezing of venous blood samples.in field studies.

Vitamin B3 1 Urinary excretion of metabolites Urinary excretion The excreted metabolites are stable during(Niacin) (1-methyl nicotinamide and 1- storage, samples are easily collected and

methyl-2-Pyridone-5-carboxamide). the method has been successfully used infield surveys.

Vitamin C 1 Serum/plasma concentration Serum Although storage and transport of serum2 Leukocyte concentration concentration samples requires freezing and may be3 Urine excretion problematic, serum vitamin C is an easier

measure and requires lower samplevolume than the isolation of white bloodcells. Urine excretion only reflects recentintake and more research is required toassess how useful it is in populationsurveys.

For a consideration of the sample sizes required for different assessment methods see Annex 3.

TECHNICAL NOTES



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atio

ns w

ere

perfo

rmed

with

Epi

Info

6.0

4 an

d ar

e ba

sed

on a

pop

ulat

ion

size

of 5

00,0

00 a

nd a

des

ign

effe

ct o

f 1.5

for c

lust

er su

rvey

s17

‘Indi

cato

rs fo

r Ass

essin

g Vi

tam

in A

Def

icie

ncy a

nd th

eir A

pplic

atio

n in

Mon

itorin

g an

d Ev

alua

ting

Inte

rven

tion

Prog

ram

mes

’ p.7

(199

6) W

orld

Hea

lth O

rgan

isatio

n, G

enev

a W

HO

/NU

T/96

.10

18Th

e le

tter

cod

es b

egin

ning

in X

, XN

, X1B

etc

. are

shor

than

d fo

r the

diff

eren

t typ

es o

f xer

opht

halm

ia19

‘Ass

essm

ent o

f iod

ine

defic

ienc

y diso

rder

s and

mon

itorin

g th

eir e

limin

atio

n. A

gui

de fo

r pr o

gram

me

man

gers

.’ (20

07) 3

rd E

d., C

hapt

er 4

, WH

O/U

NIC

EF/IC

CID

D20

Figu

res g

iven

her

e ar

e fo

r the

con

cent

ratio

n of

iodi

ne in

ur in

e, n

ot th

e pr

eval

ence

.21

N/A

– N

ot a

pplic

able

TECHNICAL NOTES


MODULE 4 Micronutrient malnutritionPu

blic

hea

lth c

ut-o

ffs fo

r ind

icat

ors

of m

icro

nutr

ient

def

icie

ncie

s an

d e x

ampl

e sa

mpl

e si

zes

(con

tinue

d)

Mic

ronu

trie

nt D

efic

ienc

y In

dica

tor

Reco

mm

ende

d A

geD

efin

ition

of a

Pub

lic H

ealth

Pro

blem

Gro

up fo

rPr

eval

ence

Prev

alen

ce S

urve

ysSe

veri

tyPr

eval

ence

(%)

to d

etec

tPr

ecis

ion

Sam

ple

size

Iron

Def

icie

ncy22

Anae

mia

(Non

-pre

gnan

t wom

enW

omen

, Chi

ldre

nLo

w5-

205.

02.

543

8ha

emog

lobi

n <

12.0

g/dl

; chi

ldre

nM

ediu

m20

-40

20.0

7.5

164

6-59

mon

ths <

11.0

g/dl

)23H

igh

≥ 4

040

.010

.013

9

Berib

eri24

Clin

ical

Sig

nsW

hole

pop

ulat

ion

Mild

≥ 1

cas

e &

< 1

%–

––

Mod

erat

e1-

41.

00.

52,

275

Seve

re≥

55.

02.

543

8Th

iam

ine

pyro

phos

phat

e ef

fect

Who

le p

opul

atio

nM

ild5-

195.

02.

543

8(T

PPE)

≥ 2

5%M

oder

ate

20-4

920

.07.

516

4Se

vere

≥ 5

050

.012

.010

1U

rinar

y th

iam

ine

per g

cre

atin

ine

Who

le p

opul

atio

nM

ild5-

195.

02.

543

8(A

ge g

roup

spec

ific

cut-

offs

)M

oder

ate

20-4

920

.07.

516

4Se

vere

≥ 5

050

.012

.010

1

Brea

st m

ilk th

iam

ine

(< 5

0 (g

/L)

Lact

atin

g w

omen

Mild

5-19

5.0

2.5

438

Mod

erat

e20

-49

20.0

7.5

164

Seve

re≥

50

50.0

12.0

101

Die

tary

inta

ke (<

0.3

3mg/

1000

kca

l)W

hole

pop

ulat

ion

Mild

5-19

5.0

2.5

438

Mod

erat

e20

-49

20.0

7.5

164

Seve

re≥

50

50.0

12.0

101

Infa

nt m

orta

lity

Infa

nts 2

-5 m

onth

sM

ildN

o in

crea

se–

––

in ra

tes

Mod

erat

eSl

ight

pea

k–

––

in ra

tes

Seve

reM

arke

d pe

ak–

––

in ra

tes

22Cl

assif

icat

ion

prop

osed

in:‘

The

Man

agem

ent o

f Nut

ritio

n in

Maj

or E

mer

genc

ies’

(200

0) W

orld

Hea

lth O

rgan

isatio

n, G

enev

a23

Cut-

offs

are

giv

en fo

r < 1

000m

and

ma y

nee

d to

be

adju

sted

acc

ordi

ng to

age

, sex

and

alti

tude

24Cr

iteria

pro

pose

d in

: ‘Th

iam

ine

Def

icie

ncy a

nd it

s Pre

vent

ion

and

Cont

rol in

Maj

or E

mer

genc

ies’

p.14

(199

9) W

HO

/UN

HCR

, Gen

eva

WH

O/N

HD

/99.

13

TECHNICAL NOTES



25Pr

ovisi

onal

crit

eria

sugg

este

d in

‘Pel

lagr

a an

d its

Pre

vent

ion

and

Cont

rol in

Maj

or E

mer

genc

ies’

WH

O/U

NH

CR, 2

000,

WH

O/N

HD

/00.

10 a

nd ‘M

anag

emen

t of N

utrit

ion

in M

ajor

Em

erge

ncie

s’, W

orld

Hea

lth O

rgan

isatio

n, G

enev

a, 2

000

26Al

thou

gh th

e us

e of

the

urin

ary

ratio

of 2

-pyr

idon

e:N

-met

hyl n

icot

inam

ide

is pr

ovisi

onal

ly re

com

men

ded

in W

HO

pub

licat

ions

, sub

sequ

ent r

esea

rch

has d

emon

stra

ted

that

whe

n ur

ine

is co

llect

ed a

t a si

ngle

tim

e po

int,

such

as d

urin

g a

surv

ey, t

he m

etab

olite

ratio

is n

ot a

stab

le in

dica

tor o

f nut

ritio

nal s

tatu

s.27

Rece

nt su

rvey

wor

k fro

m a

n ar

ea o

f Ang

ola

whe

r e p

ella

gra

is en

dem

ic h

as su

gges

ted

that

this

cut-

off n

eeds

to b

e re

vise

d up

war

ds to

1.6

mg/

g cr

eatin

ine,

and

that

the

mea

sure

men

t of t

he 2

-pyr

idon

e m

etab

olite

pro

vide

s is

a m

ore

relia

ble

anal

ytic

al m

easu

r e. (

Seal

et a

l. (20

07) ‘

Low

and

def

icie

nt n

iaci

n st

atus

and

pel

lagr

a ar

e en

dem

ic in

pos

t war

Ang

ola’

Am

J Cl

in N

utr 8

5, 2

18-2

24)

28Pr

ovisi

onal

crit

eria

sugg

este

d in

‘Scu

rvy a

nd it

s Pre

vent

ion

and

Cont

rol in

Maj

or E

mer

genc

ies’

p.9

(199

9) W

orld

Hea

lth O

rgan

isatio

n/U

NH

CR W

HO

/NH

D/9

9.11

Publ

ic h

ealth

cut

-offs

for i

ndic

ator

s of

mic

ronu

trie

nt d

efic

ienc

ies

and

exam

ple

sam

ple

size

s (c

ontin

ued)

Mic

ronu

trie

nt D

efic

ienc

y In

dica

tor

Reco

mm

ende

d A

geD

efin

ition

of a

Pub

lic H

ealth

Pro

blem

Gro

up fo

rPr

eval

ence

Prev

alen

ce S

urve

ysSe

veri

tyPr

eval

ence

(%)

to d

etec

tPr

ecis

ion

Sam

ple

size

Pella

gra25

Clin

ical

Sig

ns (D

erm

atiti

s) in

surv

eyed

Who

le p

opul

atio

n or

Mild

≥ 1

cas

e &

< 1

%–

––

age

grou

pw

omen

>15

yea

rsM

oder

ate

1-4

1.0

0.5

2,27

5Se

vere

≥ 5

5.0

2.5

438

Urin

ary

N-m

ethy

l nic

otin

amid

eW

hole

pop

ulat

ion

orM

ild5-

195.

02.

543

8<

0.5

mg/

g cr

eatin

ine26

, 27

wom

en >

15 y

ears

Mod

erat

e20

-49

20.0

7.5

164

Seve

re≥

50

50.0

12.0

101

Die

tary

inta

ke o

f nia

cin

equi

vale

nts

Who

le p

opul

atio

n or

Mild

5-19

5.0

2.5

438

<5

mg/

day

wom

en >

15 y

ears

Mod

erat

e20

-49

20.0

7.5

164

Seve

re≥

50

50.0

12.0

101

Scur

vy28

Clin

ical

sign

sW

hole

pop

ulat

ion

Mild

≥ 1

cas

e &

< 1

%–

––

Mod

erat

e1-

41.

00.

52,

275

Seve

re≥

55.

02.

543

8D

efic

ient

seru

m a

scor

bic

acid

Who

le p

opul

atio

nM

ild10

-29

10.0

5.0

208

(< 0

.2m

g/10

0ml)

Mod

erat

e30

-49

30.0

10.0

121

Seve

re≥

50

50.0

12.0

101

Low

seru

m a

scor

bic

acid

Who

le p

opul

atio

nM

ild30

-49

30.0

10.0

121

(< 0

.3m

g/10

0ml)

Mod

erat

e50

-69

50.0

12.0

101

Seve

re≥

70

70.0

15.0

54

Documents

PART 2: TECHNICAL NOTES · Type 1 nutrient deficiencies result in specific deficiency dis-eases, do not always affect growth, but will affect metabolism and immune competence before