Transcript PowerPoint

Minerals and trace
elements
Dr K N Prasad MD., DNB.
Community Medicine
Seven Food Substances
Dietary Fibre
Water
Minerals
Food Substances
Proteins
Vitamins
Fats
Carbohydrates
Minerals
50 chemical elements are identified
Important for Growth, Development , regulation
of vital functions
Major : calcium, Phosphorous, Sodium,
Potassium, Magnesium
Minor: Required less than a few milligram per
day. Ex. Iron, Iodine, Fluorine, Zinc, Copper,
Cobalt, Chromium, Manganese, Molybdenum,
Selenium, Nickel, Tin, Silicon, Vanadium
Trace elements
 A naturally occurring, homogeneous, inorganic
substance required in humans in amounts less
than 100 mg/day
Bioavailability of minerals are low in vegetarian
diet.
Excess amounts are injurious to health
Iron
Adult human body contains 3-4 Gm
60-70% is present in Blood and rest in storage form.
Each Gm of Hb contains 3.34mg of Iron.
Requirement :
1 mg per day for Male
2.5 mg for Females
3.5 mg for Females in Physiological stress
conditions
Functions of iron
Iron is a part of all cells and has many different
functions
Hb Carries of oxygen to the tissues
Brain development along with Folic acid
Myoglobin Facilitates oxygen use and storage in
muscles
An integral part of enzyme reactions in various tissues
( Cyotchromes, Catalases, etc)
Regulation of Body temperature
Catecholamine metabolism
Susceptibility to infection
Sources of iron
 Haem Iron:
 Liver, meat, poultry, Fish
 Non Haem Iron:
 Cereals, GLV, Legumes,, Nuts, Oil seeds, Dried
Fruits, Jaggery
 Factors interfere in absorption are enzymes in
the food – Phytates, Oxalates, Phosphates,
Dietary fibres
 Ascorbic acid is the most potent enhancer iron
Public Health problem
Categorized as one of the top ten most serious health
problems in the modern world (WHO)
 As many as 4-5 billion people (66-80% of
population) may be iron deficient
 2 billion people (>30% of population) are anemic
Iron deficiency in young children is the rule rather
than the exception (from 45 to 70 percent prevalence
Anemia is a fact of life for almost 500 million of
women of childbearing age(~40% of 15 to 40 y old
females in developing world)
 More than 1,000 severely anemic young women die
every week in the perinatal period because of
inadequate iron status
Iron loss
In adults – 1 mg per day
Menstruating women – 2 mg per day
Hemorrhages are common causes
IUCD may loss result in blood loss
Storage
Stored in Liver, Spleen, Bone marrow,
Kidneys
Iron Deficiency
Occurs in 3 stages:
First Stage: Decreased storage without any other
detectable abnormalities
Second Stage: stores are exhausted, serum
Ferritin level decreases.
Third Stage: Decrease in Hemoglobin percentage
Functional disturbances: decrease in resistance to
infection, increase morbidity & mortality,
decreased work performances, impaired cell
mediated immunity
Iron
Signs of iron deficiency anemia include:
Fatigue
Headache
Exertional dyspnoea
Cardiovascular stress
Poor tolerance to heavy blood loss
Evaluation of iron status
1. Hemoglobin Concentration: relative index
of iron deficiency. ( early Anemia if Hb is
10-11g% & marked anemia Hb is < 10g%).
2. Serum Iron concentration: useful index
( Normal 0.8 to 1.8mg /L)
3. Serum Ferritin level: Gold standard &
sensitive tool for evaluation and reflects the
size of the iron status ( < 10Micrgms/L)
4. Serum Transferrin Saturation: 16% - 30%
Correction of Iron Deficiency
Oral iron supplements
100 200 mg elemental iron daily
Higher doses are of no benefit
Ferrous sulphate 65mg/tab
Pregnant women- 100mg/tablet (+ folic
acid)
Iodine
 Essential Micronutrient
 Body normally has 20-30 mg of iodine and more than
75% is in the thyroid gland,
 rest is in the mammary gland, gastric mucosa, and blood
 it’s only function is related to thyroid Hormone
 Required for synthesis of thyroid hormone
 Thyroxin (T4) – 4 atoms of iodine per molecule
 Triiodothyronine (T3) – 3 atoms of iodine per molecule
Requirement per day is 150 micrograms
Iodine
Food Sources – 90% intake
Foods of marine origin (seaweed), processed foods,
iodized salt
Fresh Water – small & Variable
Small amounts in Milk, meat, Vegetables, Cereals
etc.
Goitrogens occurring naturally in foods can
cause goiter by blocking absorption or utilization of
iodine (cabbage, turnips, peanuts, soybeans)
Iodine - Absorption and Excretion
Iodine is absorbed in the form of iodide
occurs both as free and protein-bound iodine in
circulation
iodine is stored in the thyroid where it is used for
the synthesis of T3 and T4
hormone is degraded in target cells and in the
liver and the iodine is conserved if needed
excretion is primarily via urine
small amounts from bile are excreted in the feces
Iodine - deficiency
 Goitre—enlargement of the thyroid gland
 deficiency may be absolute—in areas of deficiency,
 or relative—adolescence, pregnancy, lactation
 goiters are more prevalent in women and with increased age
 Iodine deficiency is the world’s most prevalent cause of brain
damage
 Serious iodine deficiency during pregnancy may result in
stillbirths, abortions and cretinism
 the less visible, more pervasive form of iron & iodine
deficiency that lowers intellectual performance at home and
school may have far greater global and economic impact
Public Health problem of Iodine
 By the year 2000,
 Global prevalence of iodine deficiency from 30% to <15%
 Adding iodine to 2/3 of the world’s household salt
 70 million newborns protected in some Degree
 Every year, 50 million children are born without the
protection that iodine offers to the growing brain and body
 About 18 million of those will suffer some significant
degree of mental impairment
 Iodine deficiency remains the single greatest cause of
mental retardation
 The one third of the world’s people without protection by
iodized salt are the most marginalized populations –
economically, culturally and geographically
 Sustainability is another battle: salt iodization is slipping
back in several countries
Epidemiological assessment
Prevalence of Goitre
Prevalence of Cretinism
Urinary iodine excretion
Prevalence of Neurological hypothyroidism
Thyroid Function tests
Neonatal Hypothyroidism is a sensitive indicator of
environmental iodine deficiency
Serum T4 is more sensitive indicator among adults
Fluorine
 It is found in combined forms
 96% of fluorides in the body found in bone and teeth.
 An essential for normal mineralisation of bones and
formation of dental enamel
Source:
 Drinking water : Fluorine in the drinking water is
0.5 mg per ltr. Excess of fl > 3mg causes flourosis.
 Foods: Sea fish, cheese, Tea
 It is a two edged sword ( deficiency or excess)
Zinc
 Adult body contains 1.4 to 2.3 gms of Zinc
 Plasma level- 96Microgm per 100 ml ( adults), 89
Microgram per 100 ml (children)
Functions are
 Active role in metabolism of glucose and proteins
 Synthesis of insulin by pancreas
 Immunity functions
Food sources :
 meat, milk, fish
 Plant sources have low bioavailability
Zinc
On of the ten biggest factors contributing to burden
of disease in developing countries
 Zinc interventions could reduce child deaths
globally by 63%
 South East Asia and Sub-Saharan Africa highest
risk of zinc deficiency:
 Inadequate intake – 1/3 of the population
 Stunting – 40% of pre-school children
Zinc used as a (part of) curative intervention for
severe malnutrition and diarrhoea
Zinc deficiency
1. Growth failure
2. Sexual infantilism in adolescents, loss of taste,
delayed wound healing, decrease in
immunosynthesis.
3. Spontaneous abortions, stillbirths, congenital
malformations, anencephaly
4. LBW, Intra Uterine deaths, premature labour.
5. Requirement
6.
is 15mg for men
12 mg for women, 10mg for children
Thought for the day
An advice is like snow,
the softer it falls,
the deeper it penetrates
and the longer it dwells.
Thank you