MicromineralsProf. Chandrani Liyanage

ObjectivesSources Body poolsPrevalence of deficiencyClinical features in deficiencyAbsorption Requirements and recommendationsDeleterious effectsImplicationsNational plan to combat the deficiency

Iron

Iron deficiency is the most common nutritional disorder in the world Affects - women of reproductive age (15-49y) - young children in tropical and subtropical regions

Has the greatest overall effect in terms of premature death, ill-health and lost earnings

Metabolism and physiologyIron in human body - about 2.3g in adult women 3.5g in men

Of which 73% haemoglobin (2-2.5g of iron) 10% myoglobin (130mg of iron) 3% active iron containing heme and flavin enzymes and transport iron (labile Fe 80- 90mg, tissue Fe 6-8mg, trans Fe 3mg)Remainder 14% in women and children in storage SF & haemosiderin (0.3g) 25% in men in storage (1.0g)

Childhood & adolescenceID less common as rate of growth decreasesDuring adolescence prevalence rises again as iron needs increase with adolescent growth spurtMore common among pregnant adolescents

Iron needsPregnancy imposes increased needs. At risk of developing an iron responsive depression in Hb conn in the 3rd TrimesterInfancy - needs are primarily for growth. High Hb conn and abundant neonatal iron stores protect until 4 months (stores deminish by 4th month).Term infants at a greater risk of developing ID between 4-12 months and after.In infants absn is 4 times greater than excretion and the difference is used for growth. Risk largely depends on the complementary feeding.

Iron deficiencyIs rare in formula fed infantsIs common in unfortified formula or cow milk fed Exclusively breastfed infants develop after 6 monthsLow birth infants develop after 2 months need iron supplementsFe needs are greater due to low neo stores and rapid relative growth rateA dose of 2-3mg elemental iron/kg /day recommended

Deficiency - DefinitionsAnaemia Hb conn or Hct

Iron deficiency Lack of iron that is severe enough to impair the production of RBC, but not necessarily to the extent that Hb falls

Prevalence of anaemiaGlobal in 2005 47.4% in preschool children 25.4% in school children 41.8% in pregnant women 30.2% in non-pregnant women 2.7% in men 23.9% in elderly

SEAsia 65.5% in preschoolers 48.2% in preg. Women 45.7% in non-preg, women

In Sri Lanka1973 38% men 68% women 78 primary schoolers 1996 15% preschoolers 58% children of 6-11y 36% adolescents 45% nonpreg. Women 56-78% preg. women 2001 29.9% preschool 29.3% pregnant 21.6 nonpregnant 2006/07 20.3% prelimenary school 40% pregnant 35% nonpregnant (15-49)

WHO recommended standards below which anaemia is likely to be present

Cut-off level of haemoglobinUp to 6 years 110g/l6-14 years 120g/l15-74 years 120g/lPregnancy 110g/l (100g/l in 2nd Trime)Adults (male) 130g/l

Classification of anaemia as a problem of public health significancePrevalence % < 4.9 - no PH problem 5-19.9 - mild PH pr..

20-39.9 - moderate PH

> 40 - severe PH

Iron lossLoss primarily through faeces in healthy individuals (0.6mg/day)And, bile and desquamated cells & through blood in minute quantitiesIn women through menstruation (30ml/month) (additional req 0.5mg/day)About 10% women loose more than 30ml, likely anaemic and, need additional iron each dayIf total loss > 1.5mg/d positive balance not maintainedLosses occur due to aspirin intake, bleeding tumours & ulcers, diahorreal diseases , chronic malaria, parasitic infectionsMethod of contraception pill decreases to and IUCD doubles the bleeding

Iron absorptionChemical form of Fe more important than the amount determines the potentially available Fe for absnHeme Fe is absorbed more than twice as effeciently as nonheme FeLow pH helps in dissolving ingested Fe and facilitates enzyme reduction of ferric to ferrous by a brush-border ferrireductase.Duodenal crypt cells mature into absorptive enterocytes for absn of Fe

Factors determine absorption1. Enhancers vit C, foods rich in vit C meat factor animal proteins

2. Inhibitors - phytates and phytic acid polyphenols high Ca and Mg intake tea, coffee, fiber, non-albuminous part of egg soy protein

3. Physiological factors Low stores increases Good stores decreases4. Fe losses from the body5. Increased requirements during infancy, pregnancy, adolescence after surgery

Absorption of Fe from iron fortified foods and supplementsEg. Cereals, milk powders, vitamin drops, sauces, complementary foods, sugar etc. Ferrous sulphate is usually used. (not good for long term storage due to soluble form of Fe promote fat oxidation and rancidity)Influenced by the dose (

Absn of Fe from multi mineral supp & fortified foodsLess is absorbed from certain MMSs than when given alone (CaCO3 and MgO are inhibitory). If the dose is reduced to 250mg and 25mg the absn is almost double.The Ca level should not go beyond 250mg in a MMS.

Clinical featuresDue to low Hb shortness of breath lead by physical exertion Increasing lethargy and fatigue Headache, tinnitus and taste disturbances Pallor of conjunctiva, tongue, nails beds (and soft palate as severity increases) Long term IDA papillary atrophy of the tongue and spoon shaped nails Enlargement of spleen Behavioral changes in children, impaired cognition Short attention spans, poor learning ability

Deleterious effects of IDAIn children Impairment in neuronal growth and brain function Become irritable and apathetic Impaired mental and physical development Permanent neurological damage Hinders defense against infection and temp regulation Increased attacks of malaria, angular stomatitis, glossitis

ContdIn pregnant women Increased risk of maternal morbidity and mortality - premature delivery - foetal morbidity and mortality Milder degrees of anaemia assocoated with LBWPlacental hypertrophyLow stores of Fe and folate in the new bornPoor maternal weight gain

Contd..In adults Reduced work capacity (related to Hb)Work out put is significantly lessReaching socio-economic consequencesIncreased lactic acid levels and tachycardia with exerciseReduced activity of intestinal enzymesReduced growth rateImpaired bodily functions

Estimated dietary requirement (EDR) and RDA of iron mg/day. EDR RDA, 2001 (US-FNB)

0-1yr 21 11 1-2 12 07 2-6 14 4-8yr 10 6-12 23 9-13yr 08 boys 12-16 36 14-18yr 11 girls 12-16 40 14-18 yr 15 men >16 23 >18yr 08 women(menstruating) 48 18 (postmenopausal) 19 >51yr 08 (pregnant) 30-60 27 (lactating) 26

Public health implications of IDAAssociated with poor reproductive performanceHigher proportion of maternal deaths (10-20% of total deaths)Higher incidence of LBWHigher incidence of IUMImpairs scholastic performanceImpaired psychomotor devt, interlectual performanceDecreased resistance to infectionReduced work capacity, esp with intense exercisesReduced productivityIncreases risk of lead toxicity (due to shared absorptive mechanism)

Risk factors for IDAPoor iron stores at birthDietary inadequacyIncreased demands due to rapid growth(preg, inf, puberty, childhood)Malabsorption and increased losses (repeated episodes of doarrhoea, hook worm infestation and ascariasis, repeated attacks of malaria in endemic areas)

Contd..Closely spaced pregnancies, pph, poor obstetric care, prolonged lactation, use of intra uterine contraceptive devicesHaeglobinopathies Thalassemias and sickle cell anaemia (abnormal formation of Hb a nonnutritional factor)Drugs and other factors Radiation therapy, leukemia Anti-cancer and anti-convulsant drugs In chronic inflammatory conditions (arthritis) In GI blood loss

Control of nutritional anemiaDirect intervention a) supplementation b) fortificationIndirect intervention a) start breast feeding immediately and continue b)educational programmes c) reduction of pathological losses (control of hook worm and malaria) d) Regular and frequent assessment of Hb and iron status of population e) study the causal factors in the area f) train field staff to identify the risk individuals g) encourage regular ANC visits

Supplementation & FortificationIron pills and dropsComplementary foods and milk powders enriched with ironCentrally processed infant foodsCereal-legume supplements (Thriposha)School biscuitsCereals (wheat flour, rice), salt, sauces, sugar etc.

Edu programmesIncreased production and consumption of iron and folate rich foodsInclude even small quantities of non-veg foodsVit C rich foods to minimize inhibition by phytates & polyAvoidance of tea and minimize coffeeInclusion of yoghurt and fruit juices in the dietInclusion of pulses and green leaves in daily dietIntake of supplements in between mealsEmphasize the special needs and importance of FeEncourage home gardeningIntake of supplemental iron helps to reduce fatigue and increase ability to workIntroduce cheap and locally produced iron rich foods

National Plan to combat anaemia in pregnant mothersAdvises on good iron sources (pulses & legumes, green leafy veg in addition to meat and fish Inclusion of vit C and rich foods, even a small amt of animal food, not to include much tea and Ca supplements. Promoting fermented and germinated food.To supplement all the preg mothers with Fe and folic acid supplements after 12 weeks of gestation. Mothers be made aware of side effects (vomiting, nausea, loss of appetite etc.). Correct consumption of supplements and regular clinic visits.

To identify anaemic mothers by the Hb level and report as mild, moderate and severe.To give parenteral iron to severe anaemics. Advise them on high protein diet. To treat and control paracitic infections after 1st trimester (100mg mebendazole twice daily for 3 consecutive days). To prevent worm infection, use latrines, wearing slippers, hygeinic source of water, good health habits etc.To treat and prevent malaria in endemic areas (300mg of chloroquin once a week during preg and 42 days after delivery).

Information, education and communicationObtain information about anaemia from the FHWs & people in the areaImplementation of proper health education programesRisk groups (young women, working women, urban poor, estate workers & refugees) be given more attentionMake all the health workers more concern about the health message and find that they convey the messages to the publicDoctors to supervise all these educational programs