3. Macrominerals
• ~ 4% of body weight
• Found in large quantities
– More than 100 mg/d required
• Calcium
• Phosphorus
• Magnesium
• Sodium
• Potassium
• Chloride
• Sulfur
7. Biological role of calcium
• Most of the calcium in body is bound in the
bone and teeth (99%)
• 1% is found in the blood and tissues for the
purpose of:
– Nerve impulse transmission
– Regulation of muscle contraction
– Maintenance of acid base balance
– Regulation of biochemical reaction and blood
coagulation
9. Determinants of calcium balance
Increase Ca absorption Decrease Ca absorption
Vitamin D and PTH
lactose during same
meal
Vitamin D and PTH,
Phytate, Fiber, and
Oxalates during same
meal
Need (growth,
pregnancy, lactation)
Need
10. Dietary sources of
calcium
Milk and milk products
Cows' milk is a very rich source of calcium,
richer than human milk ( 1200mg vs 300 mg of
Ca/liter)
Fish with bones (salmon, sardines)
Turnip greens, broccoli, kale
Legumes
Fortified juices & breads
11. Calcium Deficiency
• Young children – lack of bone mineralization
and can lead to a condition like that of rickets
• In adults – can lead to osteomalacia in which
case there is demineralization of the bone
especially peripheral bones
• Low levels of free ionized Ca2+ in blood may
result in tetany
12. Ca Deficiency……
• Osteoporosis
– Type 1
• Postmenopausal women aged 51-65, affects
vertebrae and wrist
– Type 2 (“senile”)
• Men and women over 75
• Additionally affects hip, pelvis, humerus & tibia
13. Osteoporosis and
Calcium
• Osteoporosis is one of the most prevalent
diseases of aging.
• Strategies to reduce risks involve dietary
calcium.
• Both Trabecular and Cortical types of bone
affected by osteoporosis
14.
15. Bone Development and Disintegration
• Losses of both trabecular and cortical bone result in type
II osteoporosis.
– Can result in compression fractures of the spine
– Hip fractures can develop.
– Twice as common in women as in men
• The diagnosis of osteoporosis is performed using bone
density tests.
17. Age and Bone
Calcium
• Maximizing Bone Mass
– Children and adolescents need to consume enough
calcium and vitamin D to create denser bones.
– With a higher initial bone mass, the normal losses of bone
density that occur with age will have less detrimental
effects.
• Minimizing Bone Loss
– Ensuring adequate intakes of vitamin D and calcium are
consumed
– Hormonal changes can increase calcium losses.
20. • Sixth most abundant element (by weight) in
the human body and second most abundant
mineral behind calcium
• 85% is found bound in the bone
21. Physiological roles/Biological roles
• As a component of high energy molecules
such as ATP ,GTP and creatine phosphate
• Phosphate is a component of phospholipids
• Is component of the bone and teeth in
hydroxyappatite
• As an important component of nucleic acids
22. Dietary source
• Meat
• poultry
• eggs
• fish
• milk and milk products
• cereals
• legumes
• chocolate
• Soft drinks (in the form of phosphoric acids), coffee
and tea
24. Magnesium
• 4th in abundance; 20-28 g
• 55-60% in bone; 20-25% in muscle
• Sources
– Coffee, tea, cocoa, nuts, legumes, whole-
grains, green, leafy vegetables, whole grains,
tap water
• Mg may be reduced by processing
25. Functions
• Bound to phospholipids as part of cell
membranes
• Stabilizes structure of ATP
• Cofactor or activator of more than 300
enzymatic reactions
26. Recommend Dietary
Intakes
• RDA
– Men, 19-30
– Women, 19-30
– Men, >31
– Women, >31
400 mg/day
310 mg/day
420 mg/day
320 mg/day
• UL (from nonfood sources)
– 350 mg/day for age 8 and above
27. Mg Deficiency
• Associated with alcoholism or renal
disease
• Nausea, vomiting, weakness, cardiac
arrhythmia, etc. etc.
• At risk groups – excessive vomiting or
diarrhea, alcoholism, diuretic use, diabetes
mellitus, burns
28. Sodium
• Major cation of extracellular fluid
• 30% on bone surface
• 95% absorbed; excess should be excreted
by kidneys
• Major source in diet is added salt
29.
30. Recommended
Intakes
• 115 mg/day for obligatory losses
• National Research Council has suggested
500 mg/day (Salt is 39% Na thus ~1250
mg NaCl)
• Estimated Na intakes ~ 1800-5000 mg/day
(4.5-12.5 g salt)
31. Potassium
• 98% intracellular---major intracellular
cation
• Over 90% absorbed
• Potassium is not as calciuric as Na
• Excretion regulated by aldosterone
• Hyperkalemia – can cause cardiac arrest
• Hypokalemia – from vomiting/diarrhea
32. Chloride
• Most abundant anion in extracellular fluid
• Functions
– Negatively charged ion
– Part of gastric HCl
– Exchange for HCO3
- in RBC
33. Microminerals
• Needed by the body in amounts less than
100 mg/day
• Health implications more difficult to
establish because of low concentrations in
biological material
• Microminerals = trace minerals
• Optimal intake range may be fairly narrow
35. Iron
• One of the essential trace elements for life
• It occurs in human body as either ferrous (
Fe2+) and Ferric (Fe3+)
• Adult has about 2-5gm of iron distributed
throughout his/her body depending on
gender, diet, size and menstrual status.
36. Iron…
• Found in the body in two different forms
Functional or essential
• Serves metabolic or enzymatic function
– 65% in hemoglobin
– 10% in myoglobin
– 1-5% as part of enzymes
Storage forms
• Primarily as ferritin and hemosiderin, is responsible for the
maintenance of iron homeostasis
• Occurs in two forms in foods
Heme iron – bound into iron carrying proteins such as
hemoglobine ( 20 -30 % absorbed)
Non heme iron – found in both plants and animals(1-
10% absorbed)
37. Physiological function of iron
Iron Plays a vital role in:
• Binding and transport of oxygen
• Electron transfer reactions
• Gene regulation
• Regulation of cell growth and differentiation
• Immune function
• Energy metabolism and
• Cognitive function
38. Iron Sources
• Good sources of iron
– Red meats
– Enriched foods
– Whole grains including teff
– Beans
– Dark green leafy vegetables
– Dried fruits
• Dairy products tend to be low in iron
• Organ meats are high but not popular
• Contaminant iron??
– Iron obtained from cookware or soil
– Increase iron intake significantly
39. Factors Influencing Iron
Absorption
• Enhancers
– Some acids, sugars, meat, fish, poultry,
ascorbic acid, mucin
– May increase absorption from 2-3% to 8%
• Inhibitors
– oxalic acid, phytates, Ca,Zn
– iron binding phenolic compounds ( tea, coffee,
cocoa)
– Rapid transit, malabsorption, excess antacids,
decreased gastric acidity
40. Recommendations
• Men 8 mg/d of iron
• Women
– 19-50 yrs
– >50yrs
– Pregnancy
• Upper Level
– Adults
18 mg/d of iron
8 mg/d of iron
27 mg/d of iron
45 mg/d of iron
41. At Risk Groups
• Infants and young children – low iron in
milk, rapid growth & low stores
• Adolescents in growth spurt
• Females during childbearing years
• Pregnant women – expanding blood
volume, demands of fetus & placenta,
blood losses
42. Symptoms of Iron
Deficiency
• Pallor, listlessness
• Behavioral disturbances, impaired
performance on some cognitive tasks,
short attention span
• Decreased work capacity
• Impaired immune system, etc.
43. Iron Deficiency
Magnitude and Severity
• Iron deficiency is the most prevalent
nutritional deficiency in the world
• Globally, it is estimated to affect 1.25 billion
people ( near to 40% of the population)
• Typically affects > 50% of pregnant & lactating
females and children < 2 years are anaemic
44. Iron deficiency in
Ethiopia
• Prevalence not well documented in Ethiopia
• Prevalence of anemia in women
– 2011_17%
NNP plan: 9% by 2015
•Prevalence of anemia in pregnant women
2011-22%
Prevalence in children
2011--44%
EDHS 2011
47. Causes of anemia
• Multifactorial
• Major causes
– Iron deficiency
– Hookworm
– Vitamin A deficiency
– Malaria infection
– Chronic infections: TB, HIV
– Genetic defects
• Other vitamins
48. Deficiency of vitamins may cause anemia
• RBC production (erythropoeisis)
– Vitamin A, Folic Acid, B12, B6, riboflavin
• Protect mature RBC free radical oxidation
– Vitamin C, Vitamin E
• Fe mobilization
– Vitamin A, Vitamin C, riboflavin
• Fe absorption
– Vitamin C
49. Public Health Significance
of anaemia
The prevalence of anemia as a public health
significance is categorized as follows:
• < 5%, no public health problem;
• 5 – 19%, mild public health problem;
• 20 – 39%, moderate public health problem;
• ≥40%, severe public health problem.
50. Consequences of Iron Deficiency and Anemia
• Decreased work capacity
• Prematurity and LBW
• Perinatal mortality
• Maternal mortality
• Child mortality
• Impaired neuro-cognitive function in children
51. Effective control of anemia through combination of
strategies
• Increased iron intake
– Iron supplementation
– Fortification of foods with iron (especially weaning
foods)
• Control of parasitic infections (diagnosis and
treatment, chemoprophylaxis, preventing
transmission)
• Increased intake of other vitamins such as vitamin A,
folic acid through
– Supplementation, Fortification, Nutrition Education
52. Special case -Infants
• Infants are born with high iron stores
• Human milk has low iron content but
bioavailability is high
• First 2-3 month of life: exclusively BF infant is
in positive iron balance
• During 3-6 month of life infants are in negative
balance
54. • thyroid hormones control:
– Cell metabolism,
– Neuromuscular tissue growth and
– Development, especially the fetal
perinatal brain
• Present in minute amounts (15-20 mg) in the body
• >90% (3/4 th)of iodine stored in the thyroid
Iodine
• Iodine is an integral
thyroid hormones (Thyroxine (T4)
constituent of the
andTriiodothyronine (T3))
55. • Food Sources of iodine
– Content in foods reflects soil
concentrations
– The richest dietary sources of iodine are
• Iodized salt
• Seafood
• Seaweed
• Foods of both animal and plant origin which grazed
or cultivated on iodine sufficient soils.
56. Interaction with other
nutrients
• Deficiencies of selenium, iron and vitamin A
exacerbate iodine deficiency
– During selenium deficiency
• Accumulated peroxides may damage the thyroid gland
due to impaired production of the selenium-dependent
gluthathione peroxidase
• Selenium deficiency impairs thyroid hormone
metabolism as the monodeiodination of T4 into T3 is
catalyzed by selenium-dependent enzymes called
iodothyronine deiodinases
57. • Iron deficiency
– Reduces the iron-dependent hemoprotein
thyroperoxidase (TPO)
• TPO catalyzes the oxidation of iodine and its
substitution for hydrogen in the tyrosine residues
and the H2O2 dependent generation of the
iodothyronines
– Iodine + Tyrosine → Iodothyronines (MIT or DIT )
• TPO also catalyzes the coupling of MIT and DIT to
yield iodothyronine, the precursor of T3 and T4
– MIT + DIT → T3 or T4
• Vitamin A deficiency
– Activates thyroid stimulating hormone (TSH)
and increases risk for goiter through decreased
vitamin A mediated suppression of the
pituitary TSHβ gene.
58. Goitrogens
• Substances in the diet that interfere
metabolism
• Thiocyanate in cassava
– decreases Iodine uptake by thyroid
– Suppresses circulating T4
with iodide
• Goitrin in cabbage, cauliflower, broccoli,
turnips, brussel sprouts, rutabaga, etc.
• Humic substances from unclean drinking water are
reported to interfere with thyroidal iodination
59. Measures to reduce the cyanogenic glycosides in
cassava
• Cooking
• Peeling of the outer
part
• Fermentation
60.
61. TRH produced by
the hypothalamus
controls TSH
production in the
anterior pituitary
Low T3 & T4 levels
Up-regulate; high
levels down-regulate
the thyroid; increase
in energy need
increases activity
62. RDA for Iodine
Infants 0-6 month: 100 µg
7-12 month :120 µg
Children 1-8 yr: 90 µg
Adolescents: 120-150 µg
Adult men and women: 150 µg
Pregnant/lactating women: 200 µg
UL – 1,100 micrograms/day
Dietary Reference Intakes, Institute of Medicine, National
Research Council, Wash DC, 2001
63. Iodine Deficiency disorders (IDD)
• Include spectrum of disabilities caused by
environmental iodine deficiency
• Problem in many countries
Cause
• Low level of iodine in soil therefore in local
crops & water supplies
• Poor consumption of seafood like fish
• Increased consumption of goitrogens like
cassava, etc
64. Iodine Deficiency Disorders (IDD)
Fetal ID
Abortion
Stillbirth
Neonatal ID
Neonatal goiter
Hypothyroidism
(too little thyroid hormone)
Infant mortality
Congenital defects
Mental retardation
Paraplegia
Deaf-mutism
Dwarfism
Psychomotor defects
Cretinism
Infant mortality
B Hetzel Lancet 1983;2:1126
R Semba, 200
70. Iodine Interventions
Iodization of Salt
• Iodized salt
– Universally and regularly consumed
– Costs ~$0.04/yr/person
– Simple technology
• At a level that assures 150 µg/day is safe for all
populations
WHO, UNICEF, FAO, ICCIDD, IAEA
Iodization of irrigation water
– Effected in Xinjiang, China
– Maternal urinary iodine increased from <10 to 55 µg/L
72. Iodine Interventions
Iodized Oil Supplementation
– Effective in high risk groups
(Children, pregnant and post partal women)
– Administered every 6 to 12 months
– IDD moderate-severe
– No universal salt iodization for 1-2 year
74. Zinc
o Essential trace element
o 1.5 to 2.5 g in body
o Evidence of the essentiality of zinc in rats was
demonstrated in 1934
o Its significance in human nutrition and public health
was recognized in the 1960s, when the
consumption of diets with low zinc bioavailability
was associated with "adolescent hypogonadism and
nutritional dwarfism”
o Intracellular regulation, e.g. cellular growth,
differentiation and death
75. Sources
– The rich sources of zinc are diets of
• Animal origin such as lean red meat and sea foods
• Plant-based diets including whole-grain cereals,
pulses and legumes
– Among the modest sources of zinc are
• Fish, roots and tubers, green leafy vegetables and
fruits.
76. Functions
Zinc is an essential trace element for all
forms of life
It is involved in a number of metabolic
actions in biological systems including
– Part of many metalloenzymes (~300)
• Carbonic anhydrase
• Alkaline phosphatase
• Alcohol dehydrogenase
• Carboxypeptidase A, aminopeptidase
• Superoxide dismutase – cytoplasm
• Polymerases, kinases, nucleases, transferases,
phosphorylases, transcriptases, phospholipase C, -
aminolevulinic acid dehydratase
77. Growth and cell replication
Bone formation
Immunity
Reduction in morbidity
Pregnancy
Reproduction
Appetite
Protection of structural and functional
integrity of biological membranes
Behavior and brain function
Gene expression and protein synthesis
78. bioavailability
• Solubility
– Potential enhancers
• Soluble low molecular weight organic substances
such as amino acids and hydroxyl acids
– Antagonists
• Organic compounds such as phytates
• Zinc status
– Enhanced during periods of low dietary intake
or low body zinc
• Dietary sources
– Zinc from animal sources - better absorbed than
that from plant products
80. Deficiency
• Growth retardation – an early sign
• Poor wound healing
• Dermatitis
• Hypogeusia
• Night blindness
• Delayed sexual maturation
• Loss of taste acuity (appetite)
81. Causes of Excess Zinc Losses or Shifts
• Fever/catabolism increases muscle
breakdown and urinary zinc losses
• Diarrhea causes excess losses
• Pro-inflammatory cytokines induce
metallothioneins, which binds zinc and
results in shift to liver
82. Factors Suggesting Zinc Deficiency in a
Population
• High phytate staple foods
• Low intake of “flesh” food
• Prevalent stunting
• High rate of diarrhea
• Nutritional iron deficiency
• Geophagia
86. Deficiency
• Diseases in livestock
• Keshan & Kashin-Beck’s disease in China
• In TPN patients if not supplemented
• Interacts in thyroid deficiency
87. Roles of se
• Recognized only recently as important
nutrient in Human Nutrition
• Mostly functions as part of the antioxidant
complex called glutathione peroxidas,
thioredoxin reductase
88. Relationship with other nutrients
• Copper deficiency can possibly decrease
glutathione peroxidase activity
• Selenium requirement is decreased in the case
of high intake of Vitamin E, A, C and synthetic
antioxidants,
• Selenium requirement is increased in the case
of deficiency of anti-oxidants, high intake of
heavy metals , chlorinated hydrocarbons,
Vitamin B6•and Methionine
89. Food sources
• Like other minerals, the amount of selenium
in the food is highly dependent of the level
found in the soil where the crops are grown
and the animals grazed and drank
Good sources include:
• Seafood, meat, wheat based cereals and milk
90. Copper
• Body contains 50-110 mg
• Richest sources – organ meats & shellfish
• Nuts, seeds, legumes, dried fruits are also
good sources
• Endogenous copper from saliva & gastric
& pancreatic secretions.
91. Functions
• Ceruloplasmin – oxidase enzyme
– Oxidizes Fe2+ to Fe3+ for transport
• Superoxide dismutase in cytosol
• Cytochrome c Oxidase
• Lysyl oxidase
• Amine oxidases and others
93. Deficiency
• Hypochromic anemia
• Neutropenia
• Hypopigmentation of skin
• Impaired immune functions
• Bone abnormalities, especially
demineralization
94. Water
• Life begins in water, the most essential nutrient
• Makes up part of every cell, tissue and organ in the
body
• Accounts for about 60% of body weight
• Contributes to body parts thought of as dry
– Bone is more than 20% water
– Muscle is 75% water
– Teeth are about 10% water
95. • Two divisions of body fluid
compartments
– Intracellular fluid (inside the cells)
• Makes up about two-thirds of the body’s water
• ~ 67% or 28 L for a 70 kg
– Extracellular fluid (outside the cells)
• Makes up about two-thirds of the body’s water
– ~ 33% or 14 L for a 70 kg
• Has two components
– The interstitial fluid (fluid bathing the cells) - ~ 10.5 L for a 70 kg
– Plasma - ~ 3.5 L for a 70 kg
96.
97. • The main role of water is to maintain an
appropriate water balance to support vital
functions.
• To maintain water homeostasis, intake from
liquids, foods, and metabolism must equal
losses from the kidneys, skin, lungs, and feces.
98. Functions
• Nutrient transport
• Carries away waste
• Moistens eyes, mouth and nose
• Hydrates skin
• Ensure adequate blood volume
• Forms main component of body fluids
• Participates in many chemical reactions
• Helps maintain normal body temperature
• Acts as a lubricant around joints
• Serves as shock absorber inside the spinal cord and in the
amniotic sac surrounding a fetus
99. Water balance in the
body
• Adults consume
– 1.45 – 2.8 lts
• Foods (700 – 1000 ml)
• Liquids (550 – 1500 ml)
• Water created by metabolism (200 – 300 ml)
• Adults excrete
– 1.45 – 2.8 lts
• Kidneys (500 – 1400 ml)
• Skin (450 – 900 ml)
• Lungs (350 ml)
• Feces (150 ml)
