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8/13/2019 Ch 10 PPT Lecture (Nutr 121)
1/18
8/20/20
Copyright 2012 Pearson Education, Inc.
10C H A P T E R
Nutrients Involved inEnergy Metabolism
and Blood Health
and In Depth
2012 Pearson Education, Inc.
Vitamins and Metabolism
Vitamins and minerals
Are required for proper metabolism
Do not directlyprovide energy
Are necessary for obtaining energy from
macronutrients
Often function as coenzymes
2012 Pearson Education, Inc.
Vitamins and Metabolism
Enzyme: a protein that accelerates the rate of a
chemical reaction
Enzymes are required for all metabolic reactions
Coenzyme: a molecule that combines with an
enzyme to activate it
Some metabolic reactions require coenzymes
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Vitamins and Metabolism
2012 Pearson Education, Inc.
Vitamins and Metabolism
2012 Pearson Education, Inc.
B-Vitamins
The B-vitamins are especially important for energy
metabolism
The B-vitamins include:thiamin (B1) folate
riboflavin (B2) vitamin B12
niacin pantothenic acid
vitamin B6 biotin
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B-Vitamins: Thiamin (Vitamin B1)
Coenzyme thiamin pyrophosphate is required for
carbohydrate metabolism
Coenzyme for the metabolism of some fatty acids Enriched foods, whole grains, and pork are good
sources
Beriberi: deficiency of thiamin resulting in muscle
wasting and nerve damage, and heart failure
2012 Pearson Education, Inc.
B-Vitamins: Riboflavin (Vitamin B2)
Part of coenzymes involved in oxidationreduction
reactions
Part of the antioxidant enzyme glutathione
peroxidase
Milk is a good source of riboflavin
Ariboflavinosis: riboflavin deficiency that causes
sore throat and swollen mucous membranes
2012 Pearson Education, Inc.
B-Vitamins: Niacin
Nicotinamide and nicotinic acid
Coenzyme assists with the metabolism of
carbohydrates and fatty acids
Good sources: meat, fish, poultry, enriched bread
products
Toxicity can result from supplements
Pellagra: severe niacin deficiency
First seen in populations where dietary staple was corn
4 Ds: dermatitis, diarrhea, dementia, and death
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B-Vitamins: Vitamin B6 (Pyridoxine)
Group of six related compounds
Part of a coenzyme for more than 100 enzymes, assists in
amino acid metabolism, neurotransmitter, and assists inheme synthesis
Good sources: enriched cereals, meat, fish, poultry,
starchy vegetables
Toxicity from supplements can result in nerve damage
and skin lesions
Deficiency: anemia, elevated levels of homocysteine
High homocysteine in blood is associated with heart disease
2012 Pearson Education, Inc.
B-Vitamins: Folate
Involved in DNA synthesis, amino acid
metabolism, red blood cell synthesis
Critical for cell division of very early embryos
Good sources: ready-to-eat cereals, enriched bread
products
Toxicity can mask vitamin B12 deficiency
Deficiency: macrocytic anemia
2012 Pearson Education, Inc.
Folate Deficiency: Neural Tube Defects
A womans need for folate dramatically increases
during pregnancy
Folate is required for cell division and properformation of the neural tube
The neural tube develops into the brain and spinal
cord
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Folate Deficiency: Neural Tube Defects
The increased need for folate is critical very early
(first 4 weeks) in pregnancy, frequently before a
woman knows she is pregnant
All women capable of becoming pregnant should
consume an extra 400 g/day of folate
2012 Pearson Education, Inc.
Vascular Disease
Folate and vitamin B12 are required for the
breakdown of the amino acid homocysteine
Low folate, vitamin B12, and vitamin B6 intake may
cause an increased level of homocysteine
High homocysteine levels are associated with greater
risk of cardiovascular and cerebrovascular disease
2012 Pearson Education, Inc.
Folate Deficiency: Anemia
Anemia means without blood; any condition of
low hemoglobin levels
There are many types and causes of anemia
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Folate Deficiency: Macrocytic Anemia
Caused by a severe folate deficiency
Results in enlarged red blood cells carrying
insufficient hemoglobin Shows common symptoms of anemia, including
weakness, fatigue, difficulty concentrating,
irritability, headache, and shortness of breath
2012 Pearson Education, Inc.
B-Vitamins: Vitamin B12 (Cobalamin)
Part of coenzymes for blood formation
Required for nerve functioning
Required for homocysteine breakdown
Found only in animal-based foods
Deficiency results in anemia, low energy, fatigue,
shortness of breath, and can lead topernicious
anemia
2012 Pearson Education, Inc.
B-Vitamins: Vitamin B12 (Cobalamin)
Deficiency is due to insufficient intake or inability
to absorb the vitamin
Absorption requires: intrinsic factor and low
stomach pH
Lack of intrinsic factor production can occur
Atrophic gastritis results in inadequate stomach
acid production
Vegans are at risk for deficiency
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Vitamin B12 (Cobalamin): Pernicious Anemia
Pernicious means causing great harm or fatal
Caused by vitamin B12 deficiency
Due to low acid production in the stomach or lackof gastric intrinsic factor production
Also occurs in people who consume very little
vitamin B12 in their diet
Symptoms are pale skin, reduced energy, fatigue,
and neurological symptoms
2012 Pearson Education, Inc.
B-Vitamins: Pantothenic Acid
Component of coenzymes for fatty acid metabolism
Required for building new fatty acids
Good sources: chicken, beef, egg yolk, potatoes,
oat cereals, tomato products
No toxicity from excess pantothenic acid
Deficiency is very rare
2012 Pearson Education, Inc.
B-Vitamins: Biotin
Part of coenzymes involved in the metabolism of
carbohydrates, fats, and proteins
Important for gluconeogenesis
Biotin content has been determined for very few
foods
Deficiency symptoms include hair thinning, loss of
hair color, and red rash on face
Deficiency is very rare
Can be caused by over consumption of raw egg whites
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Choline
Choline is a vitamin-like substance
Assists in homocysteine metabolism
Accelerates the synthesis of acetylcholine,
a neurotransmitter
Good sources: milk, liver, eggs, peanuts
Deficiency can lead to fat accumulation in the liver
Toxicity can result from supplements
2012 Pearson Education, Inc.
Iodine
Iodine is a trace mineral
Critical for the synthesis of thyroid hormones
Thyroid hormones regulate body temperature,
growth, and resting metabolic rate
Good sources: saltwater fish, shrimp, iodized salt,
milk and dairy products
2012 Pearson Education, Inc.
Iodine
Excess iodine
Blocks synthesis of thyroid hormones
Thyroid tries to make more hormones
Results in goiter: enlarged thyroid
Iodine deficiency
Results in hypothyroidism and goiter
Cretinism: mental retardation from iodine
deficiency during embryonic development
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Chromium
Chromium is a trace mineral
Assists insulin as it transports glucose from the
blood into the cells
Plays a role in immune function and growth
There is very little chromium in the body
Good sources: mushrooms, prunes, dark chocolate,
nuts, whole grains
Chromium deficiency inhibits glucose absorption
by body cells
2012 Pearson Education, Inc.
Manganese
Manganese is a trace mineral
Coenzyme involved in energy metabolism
Part of the antioxidant enzyme superoxide
dismutase
Good sources: whole-grain foods, brown rice,
pineapple, pine nuts, okra, spinach
Toxicity impairs the nervous system, causing
spasms and tremors
2012 Pearson Education, Inc.
Sulfur
Sulfuris a major mineral
Component of thiamin and biotin
Stabilizes protein structure
Required for detoxification of alcohol and drugs bythe liver
Found in two amino acids
Requirement for sulfur is met by the protein in our
diets
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Blood
Blood is the only fluid tissue in the body
Functions
Transport of oxygen and nutrients to cells
Removal of waste products from cells
2012 Pearson Education, Inc.
Components of Blood
Erythrocytes: red blood cells
Transport oxygen through the body
Leukocytes: white blood cells of the immune
system
Platelets: cell fragments that assist in blood clotting
Plasma: the fluid portion of the blood
2012 Pearson Education, Inc.
Components of Blood
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Vitamin K
Vitamin Kis a fat-soluble vitamin
Coenzyme for the synthesis of proteins involved in
blood clotting
Healthful intestinal bacteria produce some
vitamin K
Good sources: green leafy vegetables
Deficiencies can result from diseases that disturb
absorption of fats (Crohns disease)
Newborns are given vitamin K at birth
2012 Pearson Education, Inc.
Iron
Iron is a trace mineral
Functions of iron
A component of the protein hemoglobin, which
carries oxygen in erythrocytes
A component of myoglobin, which carries oxygen
in muscle cells
A coenzyme involved in the metabolism of
carbohydrates, fats, and proteins
2012 Pearson Education, Inc.
Iron
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Iron
Iron can be stored in the body as ferritin or
homosiderin
Storage is usually in the liver, bone marrow,intestinal mucosa, and spleen
Two types of iron are found in foods
Heme ironfound in animal-based foods and is
more absorbable
Non-heme ironnot easily absorbed; iron not part
of hemoglobin or myoglobin
2012 Pearson Education, Inc.
Iron
Recommended intake
Recommended Dietary Allowance (RDA) varies
based on age and gender
8 mg/day for adult men
27 mg/day for pregnant women
Sources of iron
Meat, poultry, fish, clams, oysters, enriched cereals
and breads
Meat factorand vitamin C enhance absorption Dairy decreases absorption of iron
2012 Pearson Education, Inc.
Iron
What if you consume too much iron?
Iron overdose is the most common cause of
poisoning deaths in children
Toxicity symptoms: nausea, vomiting, diarrhea,
dizziness, confusion
Delayed treatment of iron toxicity can result in
severe damage to the heart, central nervous system,
liver, and kidneys
Hemochromatosisexcessive iron absorption
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Iron
What if you dont consume enough iron?
Iron deficiency is the most common nutrient
deficiency in the world
High-risk people include infants, young children,
preadolescent girls, premenopausal women, and
pregnant women
There are three stages of iron deficiency
2012 Pearson Education, Inc.
Iron
2012 Pearson Education, Inc.
Iron-Deficient Anemia
Iron deficiency results in small red blood cells that
do not carry enough hemoglobin
Symptoms are fatigue, pale skin, impaired work
performance, depressed immune function, and
impaired memory
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Zinc
Zinc is a trace mineral
Functions of zinc
Cofactor for hemoglobin production
Part of superoxide dismutase antioxidant enzyme
system
Development and function of immune system
Growth
Assists in energy metabolism
2012 Pearson Education, Inc.
Zinc
Recommended intake
RDA is 8 mg/day for women
11 mg/day for men
Sources of zinc
Red meats, some seafood, whole grains, enriched
grains and cereals
2012 Pearson Education, Inc.
Zinc
What if you consume too much zinc?
Toxicity can occur from supplements
Symptoms are intestinal pain, cramps, nausea,
vomiting, and loss of appetite
What if you dont consume enough zinc?
Deficiencies are uncommon in the United States
Symptoms are growth retardation, diarrhea, and
delayed sexual maturation
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Copper
Copperis a trace mineral
Functions of copper
Cofactor for energy metabolism
Coenzyme that assists in collagen production
Part of superoxide dismutase antioxidant enzyme
system
Required for iron transport
2012 Pearson Education, Inc.
Copper
Recommended intake
RDA for adults is 900 g/day
Sources of copper
Organ meats, seafood, nuts, seeds, whole-grain
foods
2012 Pearson Education, Inc.
Copper
What if you consume too much copper?
Toxicity is not well studied in humans
Symptoms are intestinal pain, cramps, nausea,
vomiting, and liver damage
What if you dont consume enough copper?
Copper deficiency is rare
Symptoms are anemia, reduced number of white
blood cells, and osteoporosis in children
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In Depth: Dietary Supplements
Dietary supplements are defined by the FDA as
products taken by mouth containing a dietaryingredient intended to supplement the diet
2012 Pearson Education, Inc.
In Depth: Dietary Supplements
May contain:
Vitamins
Minerals
Herbs or other botanicals
Amino acids
Enzymes
Tissues from animal organs or glands
or a concentrate, a metabolite, a constituent,
or an extract
2012 Pearson Education, Inc.
Dietary Supplement Regulation
Categorized generally as foods, not food
additives or drugs
Regulation is less rigorous than for foodadditives or drugs
FDA regulation of supplements marketing is
currently in flux
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What Consumers Should Know
FDA approval is not needed for marketing
Manufacturers are solely responsible for safety
Sellers are not required to show evidence of
safety
Purity, safety, or composition may be
questionable
No rules limit serving sizes
Once a supplement is marketed, the FDA must
prove it is unsafe for it to be removed from
stores
2012 Pearson Education, Inc.
Avoiding Web-Based Supplements Fraud
Critically assess the Web site:
What is its purpose?
Is information accurate?
Does it use reputable references?
Who owns or sponsors the site?
Who wrote the information?
Is the information current?
2012 Pearson Education, Inc.
Herbal Supplements
An herb (or botanical) is a plant or plant part
used for its scent, flavor, and/or therapeutic
properties
Consult your healthcare provider before using
herbal supplements Herbs may cause serious medical problems if
used in large amounts
Avoid using herbs when pregnant or nursing,
unless you have consulted a doctor
Active ingredients in many herbs and herbal
supplements are not known
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Should You Take Supplements?
Many people do not need supplements
Supplements are not substitutes for whole foods
Some individuals who may benefit from
supplements include:
Vegans
Athletes
Infants and children
Pregnant teens and pregnant women
Elderly people
Convalescents
2012 Pearson Education, Inc.
Chapter Review
Self Quizzes
Supplemental Videos
Go to: http://www.mynutritionlab.com/
MyNutritionLab