Deficiency Diseases of Nutrients by HC12042413859

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									     Deficiency Diseases of Nutrients In Humans
                                      Booklet No. 305
                                 Food and Nutrition: FNS - 2
Content
Preface
I. Introduction
II. Deficiency of Proteins, Carbohydrates and Lipids
         A. Protein -Calorie malnutrition (PCM)
                 1. Kwashiorkor
                 2. Marasmus
                 3. Marasmic –kwashiorkor
         B. Carbohydrate deficiency
III. Deficiency of Vitamins
         A. Fat-soluble vitamins
         B. Water-soluble vitamins
             1. Vitamin B-complex
             2. Vitamin C
IV. Deficiency of Water
V. Deficiency of Mineral Elements
VI. Conclusion

I Preface

       Nutrients are considered to be most vital for the existence of human life. Every nutrient
has got its specific physiological role to play for the maintenance, growth and development of
the body. Our diet should be adequate in all these nutrients. If the diet does not provide these in
adequate amounts dietary deficiencies and diseases are bound to occur. This booklet provides
information on the nutritional deficiency diseases in humans.

Dr. K. T. Chandy, Agricultural & Environmental Education

I. Introduction

        The human body requires an adequate supply of nutrients for its normal physiological
functions. When these nutrients are not available in the diet, deficiency diseases occur. It is
interesting to note that these deficiencies rarely occur singly. Poor dietary intake is the most
common cause of deficiency symptoms. Hence, the nutritional deficiencies arise from the lack of
specific nutrients. Even when the diet is adequate, several other factors may cause conditions
of deficiency. Some of these associated factors are made clear through the following sets of
example:

i. Poor absorption of iron in cases of hook-worm infection, of vitamin B12 in cases of anaemia
and of vitamin A in protein deficiency,
ii. loss of vitamin-A from the alimentary canal, when paraffin oil or repeatedly heated fats are
taken, of carotene and vitamin-A in cases of excess consumption of poly- unsaturated fatty
acids or in case of deficiency of tocopherols,
iii. excessive loss of nitrogen from body during fever, acute infection and as a following result of
injury,
iv. poor utilisation, for instance of vitamin A in protein malnutrition and of iodine on account of
biochemical abnormalities and
v. requirements of proteins and vitamins increase during fever infections, exposure to cold, heat,
stress, surgery, injury, treatment with drugs and anti-bodies.

        All these above mentioned factors must be considered while dealing with nutritional
deficiencies.

       Primiary nutritional deficiencies are those that are caused by inadequate or imbalanced
intake of food. Inadequacy of food almost always reduces the intake of more than one nutrient.
Secondary deficiencies are those that result from some fault in digestion, absorption, and
metabolism so that the tissue needs are not met even though the ingested diet would be
adequate.

II. Deficiency of Proteins, Carbohydrates and Lipids

        Deficiency of protein, carbohydrate and lipids are studied under two main heads: protein-
caloric malnutrition (PCM) and carbohydrate deficiency.

A. Protein-calorie malnutrition (PCM)
Protein calorie malnutrition (PCM) is one of the most important public health problems in many
developing countries including India. It is a wide-spread deficiency disease among children of
low socio-economic groups. In many areas nearly half the children do not survive to the age of
five years on account of protein-calorie malnutrition. Those who survive may suffer from
impaired growth and perhaps mental retardation.

        The diseases known as "Kwashiorkor" and "marasmus" represent extreme forms of
protein -calorie malnutrition. Kwashiorkor occurs mainly due to protein deficiency. Imbalance
between protein and carbohydrate intake also results in Kwashiorkor. Marasmus is also the
result of a continued deficiency of calories and protein as well as other nutrients the term
marasmus is derived from a Greek word meaning
"to waste".

1. Kwashiorkor
       The deficiency of proteins in the form of Kwashiorkor shows the following deficiency
features. Constant features, usual and occasional features.

a. Constant features
       The constant feature express itself in psycho-motor changes, growth retardation, muscle
wasting and oediama.

(i) Psycho -motor changes
The child becomes extremely apathetic with no interest in the surroundings and with no
appetite.
(ii) Growth retardation
There is too little supply of amino-acids for building body protein. The small supply of protein is
utilised for energy resulting in failure of growth and reduction in body weight.
(iii) Muscle wasting
Due to deficiency of protein lot of wasting of the muscle tissues occur. The child will also be
unable to hold up his head when gently pulled from a lying to a sitting position.
(iv) Oedema
Oedema occurs when there is excessive loss of nitrogen and the body tries to retain a state of
normalcy by transfusion of extra-cellular fluid to the intracellular space of the cells.
b. Usual features
The following are the common usual features:
(i) Hair chauges -discoloration, red hair, sparseness and easy pluckability of hair;
(ii) Skin changes -skin change appear in the form of dry rough and scaly skin;
(iii) Moon face -oedema leads to a full, well -rounded face and
(iv) wose stool- due to gastro -intestinal disturbance, bulky loose stools containing undigested
food result.

c. Occasional features
         Fatty liver associated vitamin deficiency and susceptibility to infection are the occasional
features.
(i) Fatty liver -Due to fat deposited inside the liver cells, the liver gets considerably enlarged
extending down.
(ii) Associated vitamin deficiency -Vitamin deficiency is manifested in the occurrence of
keratomalacia and angular stomatitis.
(iii) Susceptibility to infection -Children become more prone to infectious diseases.

2. Marasmus
        Marasmus is also a deficiency disease on account of PCM. This shows the following
deficiency symptoms.
a. The child is reduced to mere skin and bone due to diminution of muscle mass.
b. Shrunken and shrivelled skin due to loss of muscle tissues occur.
c. Dehydration occurs due to watery diarrhoea.
d. There is an evidence of acidic stools.
e. There is an evidence of sub-normal temperature
f. There is dull and dry hair
g. The abdomen may be shrunken.
h. The eyes may become large in size.
i. There is a continued feeling of hunger.
j. There is a low pulse rate.

3. Marasmic -kwashiorkor
        The symptoms of both kwashiokor and marasmus are found in some cases. This
condition is known as marasmic kwashiorkor.

        Hence, we see that PCM is characteristic of children under five years whenever the diet
is poor in protein and calories. The effect of protein deficiency in adults may show itself in the
form of loss of weight, reduced sub-cutaneous fat, anaemia, great susceptibility to infection,
frequent loose stools, general lethargy and delay in healing of wounds.

B. Camohydrate deficiency
         Carbohydrate is a very important nutrient in the human diet. A low carbohydrate diet
brings about a loss in weight. A diet rich is carbohydrates is the most important source of
energy. A diet deficient in carbohydrates leads to excessive fatigue, dehydration, water loss and
electrolyte deficits. In susceptible individuals, there is retention of uric acid which sometimes
leads to symptoms of gout. It is very important to note that low carbohydrate diets are also low
in fibre content.
        A diet deficient in carbohydrates leads to a condition known as Hypoglycemia, which is a
condition when there is a loss of glucose level in the blood. The symptoms of hypoglycemia are
hunger, weakness, trembling, sweating, headache, and if severe, leads to coma.

III. Deficiency of Vitamins

        Deficiencies of vitamins is discussed under two heads:
A. Fat soluble vitamins andB. water soluble vitamins.

A. Fat-soluble vitamins
       Fat soluble vitamin deficiency include deficiencies of vitamin A, vitamin D, vitamin E and
vitamin K

1. Vitamin A
         Deficiency of vitamin A in diet can cause a number of deficiency symptoms and defects.
Initial symptoms of deficiency of this vitamin are itching, burning and inflammation of the eye-
lids. This is followed by impaired vision in dim light, a condition known as Nyctalopia. When the
deficiency of vitamin A is severe and prolonged, the cornea becomes dry and pigmented. This
further leads to ulceration and susceptibility to infections. This stage is known as keratomalacia.
The final stage is the softening of the cornea leading to permanent deformities with subsequent
involvement of the iris lens and the whole eye. This eventually leads to total blindness and is
called xefophthalmia.

        The deficiency of Vitamin A leads to the degeneration and keratinisation of the
epithelium. This increases the susceptibility to infections of the eye, nasal passages, middle ear,
pharynx, mouth, respiratory tract, lungs and genito-urinary tract.

       Dry and scaly skin is an important symptom of the, deficiency of vitamin A. Goose
pimple like follicles appear, first on the upper arm, thighs and then along the shoulders, back,
abdomen and buttocks. This condition is generally termed as "toad's skin". The mucous
membranes of the respiratory organs like the nose, throat, trachea and bronchi becomes dry
and rough, resulting in bacterial infections.

        Vitamin A deficiency may lead to the thickening and dryness of the alimentary tract,
which results in diminished secretion of digestive juices, impaired absorption and increased
susceptibility to intestinal infection and diarrhoea. Formation of urinary stones may take place
due to the keratinisation of the epithelium of the genito-urinary tract.

2. Vitamin D
        Lack of vitamin D leads to the following deficiency symptoms and defects. Vitamin D
deficiency leads to rickets. During rickets the calcium and phosphorus level is always low. Bone
growth caeses and in more severe cases the bone which has already formed may be
demineralised. This results in clinical changes which are observed by the swelling or bending of
the ribs. This condition is known as "rachitic rosary" the long bones increase in width at the ends
and they may become curved instead of remaining straight. This leads to "knock-knees", bowed
legs, curvature of the vertebral column and deformities of the pelvic bones.

-Softening of the skull, particularly in the infants and the delayed closing of the fontanelle is
another important feature of the deficiency of this vitamin.
-The teeth of the children suffering from Vitamin D deficiency erupt late and degenerate early
because of retarded calcification. The general features of deficiency, include retarded growth,
lack of vigour, enlarged parathyroid glands, low level of calcium and phosphorus. It has been
found-that pre-mature children are more susceptible to rickets than the normal children.

-Deficiency of vitamin D in adults leads to osteomalacia- a condition in which the bones become
fragile so that they are easily susceptible to fractures.

-In old age a deficiency of both vitamin D and calcium leads to osteoporosis, a condition in
which the bones become porous and break easily.

-Renal rickets may also occur during adult life. This is because of metabolic disorders which
allow increased leakage of calcium and phosphorous from the kidneys with a resultant vitamin D
deficiency.

3. Vitamin E
       Lack of vitamin E leads to the following deficiency symptoms and defects in our body.

-Vitamin E deficiency results in increased hemolysis (breakdown) of the red blood cells leading
to anaemia.
-Premature infants also show a low level of tocopherol in the serum.
-Deficiency of vitamin E in adults has been observed only in individuals with chronic fat
malabsorption.
-However deficiency of vitamin E is not frequently reported in human body.

4. Vitamin K
        Specific needs for vitamin E and K for the human body have not been established. Lack
of vitamin K in the diet leads to the following deficiency symptoms and defects.

-Deficiency results usually from a faulty absorption of the vitamin K or due to liver disorders that
affect the synthesis of prothrombin.
-Dietary deficiency of vitamin K is rather unusual and adequate supply of it is normally available
in the body for reasons mentioned earlier. The intake of large amounts of sulfa-drugs or other
antibiotics can, however, destroy the micro-organims which synthesise the vitamin, resulting in
deficiency.
-Premature infants and those whose mothers have been taking anti-coagulants are also
susceptible to a deficiency. New born infants may have vitamin K deficiency because micro-
organisms of the right type may not have had time to get established in the intestinal tract.
-The deficiency of vitamin K results in low blood levels of prothrombin and other clotting factors
leading to an increased tendency to haemorrhage.
-Since vitamin K is fat soluble the presence of bile is necessary for its absorption.

        Disorders of the liver or gall bladder which interfere with the secretion of bile could result
in vitamin K deficiency.
B. Water soluble vitamins
        The water soluble vitamins make up a large group. They comprise of B complex vitamins
as well as vitamin C. Water soluble vitamins are not stored m the body.

1. Vitamin B-complex
All the water-soluble vitamins except one belong to the B-complex group.
a. Thiamine (Vitamin B.)
Lack of Thiamine in the diet leads to the following deficiency symptoms.

i. A very low intake of thiamine leads eventually to beri- beri, a dietary deficiency disease Beri-
Beri is characterized by degeneration of nerve tissues, especially in the arms and legs, muscle
weakness, heart disease, oedema and eventually paralysis.
ii. Thiamine deficiency may also cause some gastro intestianl disturbances accompanied by
persistent vomiting and diarrhoea, subsequent to febrile (fever) disease or surgery when the
dietary intake has been poor.
iii. Beri-Beri, a thiamine deficiency disease condition is of two kinds. Wet Beri -Beri and dry Beri-
Beri. In wet Beri-Beri, -oedema is prominent and in dry Beri-Beri there is neuritis and the heart
may also be affected (also known as cardiac Beri-Beri). Normally, it is seen that a breast-fed
infant is well nourished and healthy and mortality is very low, but when the maternal diet is low
in thiamine the breast-milk is also very poor in it and the infant develops infantile Beri-Beri with
symptoms such as palpitation of the heart, vomitting, oedema, wasting of body tissues. The
condition often results in death.

b. Riboflavin (Vitamin B2)
         Riboflavin (Vitamin B2 is an important water soluble vitamin. Insufficient vitamin B2 in
diet causes the following deficiency symptoms and defects.
i. Ariboflavinosis is believed to be one of the most common of deficiency diseases. This is said
to occur along with other deficiencies of the B-complex vitamins.
ii. When there is lack of riboflavin in the body certain characteristic physical signs appear. Some
are concentrated in the areas of the mouth, lips, tongue and the nose. The mouth becomes sore
and the tongue smooth and purplish in colour; the lips are inflamed with cracking at the comers
of the mouth, the skin is rough and scaly particularly at the folds of the nose.
iii. Other signs of riboflavin deficiency pertain to the eyes. The eye-lids become rough, there
may be blurring of vision, itching, watering, soreness and often there is increased sensitivity to
light and the eyes are easily fatigued. There is increased capillary development in the cornea,
and the eye becomes blood shot in appearance.

c. Niacin
Niacin is a water-soluble vitamin belonging to the B- complex group. It is very important nutrient
in the diet. Lack of niacin in the diet leads to the following deficiency diseases and symptoms.

i. A prolonged deficiency of niacin leads to a disease called pellagra (rough skin). Pellagra has
been called the disease of the 4 D's.
-Dermatitis (skin disease)
-Diarrhoea,
-Dementia (Failure to maintain normal mental state),
-Death.
ii. Pellagra also involves the gastro-intestinal tract, the skin, and the nervous system. Early signs
include fatigue, restlessness, headache, backache, loss of weight, loss of appetite and general
poor health and muscle pains.
iii. The first sign of pellagra appears on the skin. The skin becomes rough, scaly and ulcerated.
There is diffused hyperpigmentation resulting in darkening of complexion.
iv. Next, the gastro-intestinal tract is aggravated by the presence of intestinal parasites. The
mouth is sore, eating and swallowing is difficult, diarrhoea with profuse watery stools is
accompanied by blood and mucous.
v. In acute cases delirium is common and dementia occurs. There is decreased sensation to
touch, loss of ability of muscular coordination and finally paralysis occurs resulting in death.
d. Vitamin B6
        Vitamin B6, is a water soluble vitamin important in the diet. This vitamin is found in three
active forms-Pyridoxine (in plant products), Pyridoxal and Pyridoxamine (in animal product) It
plays a role in the conversion of tryptophan to niacin and of linoleic acid to arachidonic acid, and
in the inter- conversion of amino acids. Lack of vitamin B 6 in diet leads to following deficiency
diseases and defects.

i. In the vitamin B6 deficiency, there is reduced levels of serum and red blood cell trans-
aminases and lowered excretion of pyridoxic acid.
ii. Vitamin B6 deficiency in infants
This deficiency has been observed in infants who are fed on commercial formula in which
pyridoxine was deficient. The infants showed nervous irritability and convulsions. Other related
symptoms included anaemia, vomitting, weakness, and abdominal pain.
iii. Deficiency of vitamin B6 in adults
When the diet is deficient in vitamin B6, a rapid fall in urinary excretion of vitamin B6 and
pyridoxic acid as well as decreased blood concentrations of pyridoxal phosphate. Despite this
bio-chemical evidence of deficiency, no clear-cut symptoms have been observed in adults.

e. Pantothenic acid
        Pantothenic acid is a water-soluble B-complex vitamin. It is probably synthesised by the
intestinal bacteria and is a component of co-enzyme A. Deficiency of this vitamin is not
observed if the diet is normal. The requirements of this vitamins by the human body are not
known precisely. Deficiency of Pantothenic acid leads to the following defects and symptoms as
observed.

i. There is loss of appetite, indigestion, abdominal pain, dullness, mental depression, peripheral
neuritis with cramping pains in the arms and legs, burning sensations in the feet, insomnia and
respiratory infections.
ii. It has been observed that there is neuropathy in alcoholics, which is possibly related to
Pantothenic acid deficiency. However, when the diets are deficient in Pantothenic acid, they are
also deficient in many other factors, and hence, it is difficult to distinguish the symptoms
attributable to the lack of various nutrients.

f. Biotin
        Biotin is a water-soluble B-complex vitamin. This vitamin is synthesised in the intestines.
The precise daily requirements of biotin are not known. However, deficiency of Biotin in diet
leads to the following defects in human body.

i. Scale like appearance on the skin, muscle pain, pallor of skin and mucous membranes,
anorexia and nausea occur.
ii. The haemoglobin levels are lowered, the blood cholesterol levels were increased, and the
urinary excretion of biotin dropped below the normal levels.

g. Vitamin B12
         This is a water soluble B-Complex vitamin. Vitamin B12 is the only cobalt containing
substance essential to life. It is very important to note that Vitamin B12 deficiency is a defect of
absorption and rarely of dietary lack.
i. Deficiency of vitamin B12 leads to pernicious anaemia.
Perncious anaemia isa disease, probably of genetic origin, in which intrinsic factor is not
produced, and consequently vitamin B12 is not absorbed.
ii. With the deficiency of vitamin B12 the bone marrow is unable to produce mature red blood
cells, but releases fewer large cells (macrocytes) into the circulation. Thus, the capacity to carry
haemoglobin is reduced. The important symptoms include anorexia, prolonged bleeding time,
abdominal discomfort, loss of weight, glossitis, neurologic disturbances, including mental
depression.
iii. Megaloblastic anaemia from vitamin B12 deficiency also occurs. Malabsorption syndromes
such as sprue may also be characterised by megaloblastic anaemias resulting from deficient
absorption of vitamin Bu as well as Folic acid.
iv. Dietary deficiency of vitamin B12 has been observed in vegetarians who do not consume any
animal foods. They show, a low serum levels of vitamin B12, glossitis, paresthesias, and same
changes in the spinal cord, but did not have the characteristic anaemia. For strict vegetarians a
supplement of vitamin B-12 is indicated.

h. Folic acid
        Folic acid is an important water-soluble vitamin of the B-complex group. Folic acid
deficiency results from inadequate dietary intake or is secondary to disease. Extra amounts of
folic acid in the diet are excreted in the urine and faeces. The daily requirement of folic acid in
the diet is not exactly known.

i. When there is a deficiency of folic acid in the body, there is a reduction in the serum folate
level and also changes take place in the production of red blood cells in the bone marrow. The
anaemia that results from folic acid deficiency is characterized by a reduction in the number of
red blood cells, the release into the blood circulation of large nucleated cells (hence, known as
macrocytic or megaloblastic anaemia), low hemoglobin levels but a high colour content of each
cell, and lowered leukocyte and platelet levels.
ii. The anaemia due to folic acid deficiency has been generally found to occur in elderly patients
who have had poor diets and have various organic diseases, in pregnant women and in infants
whose formulas may be inadequate in folic acid or ascorbic acid.

iii. Folic acid deficiency frequently accompanies disease conditions in which the requirement for
the vitamin is greatly increased.
iv. Malabsorption syndromes, namely sprue, are characterized by the presence of megaloblastic
anaemias.

2. Vitamin C
         Vitamin C or ascorbic acid is an important water-soluble vitamin, but this does not
belong to the B-complex group of vitamins. Deficiency of Ascorbic acid in the diet leads to the
following symptoms and defects.
a. A deficiency of ascorbic acid results in the defective formation of the intercell1llar cement
substance.
b. Fleeting joint pains, irritability, retardation of growth in the infant or child, anaemia, shortness
of breath, poor wound healing, and increased susceptibility to infection are among the important
signs of deficiency of ascorbic acid.
c. Scurvy: Scurvy occurs as a result of deficiency of vitamin C in the diet. Scurvy is of two types:
(i) Infantile scurvy and (ii) scurvy in adults.

(i) Infantile scurvy
        A gross deficiency of ascorbic acid results in scurvy during the second 6 months of life.
Infections, fevers, and hyperthyroidism may precipitate the symptoms when the intake has been
inadequate. The symptoms are related to the weakening of the collagenous material. Pain,
tenderness, and swelling of the thighs and legs are frequent symptoms of infantile scurvy .The
baby shows a disinclination to move and assumes a position with legs flexed for comfort. He is
pale and irritable and cries when handled. Loss of weight, fever, diarrhoea, and vomitting are
said to occure frequently. If the teeth have erupted, the gums are likely to be swollen, tender
and hemorrhagic. Bone calcification is faulty because of degeneration or lack of proper
development of the bone matrix.

       The cartilage supporting the bones is weak, and bone displacement occurs. The ends of
the long bones and of the ribs are somewhat enlarged.

(ii) Scurvy in adults
        It results after several months of a diet deficient in ascorbic acid. The symptoms include
hemorrhagic spots on the skin, swelling, infection, and bleeding of the gums, tenderness of the
legs, and anaemia. The teeth may become loose and eventually may be lost. As the disease
progresses, the slightest injury produces excessive bleeding and large hemorrhages may be
seen underneath the skin. There is a degeneration of the muscle structure and of the cartilage
generally.

IV. Deficiency of Water ,;c

        The water, is an essential element in the diet for the human body. The 24 hour water
requirement is that amount that replaces the 1osses of water by the kidneys, lungs, skin and
bowel. Water is a major structural constituent of our body. All the tissues of our body including
teeth and bone, contain water. When there is inadequate intake of water or there is an
excessive losses of water from the body, through faeces, urine, lungs, perspiration certain
symptoms are said to occur. Hence, it is very important that the intake of water should be
adequate to meet the body requirements. If the intake does not meet the requirements,
deficiency is said to occur. Dehydration is said to occur when the amount of water is deficient in
the diet. The other deficiency symptoms are -it leads to decrease in peristaltic action, reduced
blood volume, poor absorption of nutrients, impairment of renal function, and circulatory failure.
Loss of water along with loss of fluid is accompanied by electrolyte losses as well.

V. Deficiency of Mineral Elements

       The body contains more than 19 minerals all of which must be derived from foods. About
4 percent of the body weight is made up of minerals. Minerals are required for the growth and
development of the body and for the formation of bones and teeth, for example, calcium,
phosphorus and magnesium.

1. Deficiency of calcium
        A deficiency of calcium in the diet results in retarded calcification of bones and teeth in
the young children. Due to the deficiency of calcium bones start bending and there is
enlargement of the ankles and wrists. The deficiency disease is known as rickets in children and
osteomalacia in adults. Repeated pregnancies coupled with inadequate dietary intake can also
give rise to the deficiency of calcium.

2. Deficiency of phosphorus
       Phosphorus is an important constituent in every body tissue. Most of this phosphorus is
present in organic combinations. A deficiency of phosphorus is very rare in human body
because diets having sufficient cereals are seldom inadequate in this nutrient. The total amount
of phosphorus in the body is much higher than that of calcium. The deficiency of phosphorus is
common in animals. Animals deficient in phosphorus, develop stiff joints and bones become
fragile and break easily.

3. Deficiency of potassium
       Ninety percent of the total potassium present in the body is found in the cells. The
remaining is distributed in the extra-cellular fluid. Plasma also contains small amounts of
potassium. Potassium is present in large amounts in the digestive juices. Excess potassium is
excreted from the kidneys.

        Primarily the deficiency of potassium is not of food origin. Impaired appetite, severe
malnutrition, chronic alcoholism and burn injuries can disturb the acid-base balance and lower
osmotic pressure. The acid-base equilibrium is also disturbed due to the deficiency of adreno-
cortical hormone, (Addison's disease). In this disease, potassium is retained and there is
excessive loss of sodium. This is the effect of imbalance of potassium in the body.

        Any condition that reduce the availability of nutrients for absorption can lead to
potassium depletions for example prolonged vomitting gastric drainage and diarrhea. Potassium
deficiency is characterised by low plasma levels of potassium (hypo-potassemia or
hypokalemia) The symptoms of deficiency include nausea, vomitting, restlessness, muscle
weakness, hypotension, tachycardia. The heart may stop in diastole.

4. Deficiency of sodium
        Sodium is present in many foods, in the form of sodium chloride. About 50 percent of the
total sodium present in the body is found in extracellular fluid. The absorption of sodium chloride
which is an organic salt in the diet occurs in the gastro-intestinal tract rapidly and is practically
completed there. Sodium is also lost through perspiration, but this depends upon the
concentration in the blood and the total volume of sweat.

        Sodium maintains normal osmotic pressure and water balance as it is the principal
electrolyte in extra-cellular fluid. Hence, the osmotic pressure and the pH(H-ion concentration)
are seriously affected when there is a disturbance in the concentration of sodium in the extra-
cellular fluid of the body tissue. Excessive sodium losses occur during the hot weather causing
muscular weakness, cramps, fatigue, vomitting and loss of appetite.

        Athletes and persons at heavy labour lose significant amounts of sodium in the sweat,
and these sodium and fluid losses must be replaced. A deficiency of adreno-cortico-tropic
hormone that is characteristic of Addison's disease leads to such large losses of sodium that the
patient hungers for salt. With persistent vomitting and dianhoea, sodium is drawn into the
gastro-intestinal tract, and ultimately the extracellular fluid is depleted of its normal sodium
content. The symptoms of sodium depletion include weakness, giddiness, nausea, lethargy,
muscle cramps, and in severe depletion, circulatory failure.

5. Deficiency of chlorine
        Chlorine is present in the body as the chloride ion. It is present in extracellular fluid as
sodium chloride. It is found within the cells as potassium chloride. Chloride ions are also known
to be present in the red blood cells. It is an essential part of the gastric juice. Chloride imbalance
is seen during severe vomitting, drainage or diarrhoea will lead to large losses of chloride and
an alkalosis because of the replacement of chloride with bicarbonate.

6. Deficiency of magnesium
       The amount of magnesium present in the body is less than that of calcium and
phosphorus. The dietary absorption of magnesium is about 40 percent. A high calcium intake
increases the requirement for magnesium as well. The unabsorbed magnesium from the diet is
excreted in the faeces.

       Under normal conditions of health and food intake magnesium deficiency does not
occur. A deficiency of it may result from mal-absorption syndrome, chronic alcoholism, toxaemia
of pregnancy. Deficiency of magnesium give rise to neuro-muscular irritability, tetanic
convulsions and convulsions.

7. Deficiency of iron
       Iron is the chief among the trace elements required for the body. The total content of iron
is very small in the body. In an adult, it is approximately 3-5 gm. It is widely distributed
throughout the body. The major portion of it is found in the blood as haemoglobin.

        Deficiency of iron occurs in the body due to an inadequate intake, poor absorption or
due to abnormal loss of blood from the body. Anaemia occurs in different forms. In hypo-chronic
anaemia, physical symptoms are manifested. The person suffering from hypochronic anaemia
looks pale in appearance, experience frequent headaches and generally looks weak. The
haemoglobin level is lower than normal and the red blood cells are smaller than normal
(microcytic). This results in poor supply of oxygen to the tissues, as a result the person always
feels tired. In normo-chromic anaemia physical symptoms like paleness are not seen. Iron
stores are depleted plasma iron level is reduced and the "iron-binding" capacity of the blood is
increased. There is less iron to combine with the transferrin (a protein). Megaloblastic anaemia
appears due to the deficiency of vitamin B12 and folic acid. The number of cells is decreased
and the cells are large in size.

8. Deficiency of iodine
        About one-third of the iodine present in adults occurs in the thyroid gland. It is about 25 -
50 mg. Iodine is a constituent of the thyroid gland. Iodine is essential for synthesis of the thyroid
hormone, thyroxine. Deficiency of iodine in the diet leads to a condition known as Endemic
goitre, which occurs in certain areas of the world where the soil has a low iodine content. As a
result the food and water also become deficient in iodine in these areas.

        Goitre is characterized by the swelling of the thyroid gland. The reduced secretion of the
thyroid gland controls the state of the connective tissue. Deficiency of thyroxine reduces the
carbohydrate oxidation resulting in the accumulation of muco-polysaccharides that give the
person a myxoemic appearance.

9. Deficiency of zinc
        Zinc is found in traces in all body tissues. The highest concentration of it occurs in the
liver, pancreas, kidneys and brain. It is also present in red blood cells and blood serum. The
deficiency of zinc in human body is very rare. There are reports that cirrhosis of liver, pernicious
anaemia, and myo-cardial infarction occur due to low zinc level in the blood. Certain cases of
growth failure (dwarfism) and hypo-gonadism are associated with zinc deficiency. It was found
that with the addition of zinc to the diet there was considerable improvement in growth and
development of the sexual organs.

10. Deficiency of fluorine
        It is one of the most active element. Traces of fluorine are present in bones, teeth,
thyroid gland and skin. It helps to protect the teeth from decay.
        Fluorine is often known to be present in the form of fluoride which may be involved in
some way in the maintenance of bone structure. Fluorides are deposited in. the developing
teeth of children. There is no deposition of fluoride on adult teeth. Deposition of the fluoride
discourages the solubility of minerals and growth of acid forming bacteria. When there is a
deficiency of fluorine during the growing period, it will result in dental caries and tooth decay.

      However, it is important to note that fluoride is required in small amounts only. A small
amount, 1 ppm, is considered enough for normal healthy teeth.

11. Other trace elements
       Manganese, molybdenum, selenium, chromium and cobalt are essential trace elements.
Studies have indicated that the mineral elements are closely inter-related and playa role in food
and nutrition. They occur in very small amounts, which are provided by ordinary diets.

        Some soils have a large proportion of selenium. The food and water of these places can
be toxic to animals and perhaps to the human beings as well. However, the effects of selenium
deficiency in humans are not known.

       Bromine, aluminium, boron, nickel and arsenic are some other trace elements that are
found in animal and plant tissues. The exact role and requirement of these minerals are not
known very well. Further research is necessary before it can be determined if they are needed
by humans.

VI. Conclusion

        In our country, a majority of the diet surveys carried out over the last several years
reveal that the diets of the bulk of our population who belong to poor socio-economic group are
inadequate. The deficiencies in the diets are both qualitative and quantitative. Among the most
poorer sections of the population, even the basic calorie requirements are not met. The intake of
proteins is also marginal while the intake of vitamins and minerals fall short of the desirable
levels of intake. The consumption o[such unsatisfactory dietary intake is reflected in the
prevalence of signs of malnutrition and deficiency diseases specifically in the low income
groups. Malnutrition is a condition when there is an impairment in health resulting from a
deficiency, excess, or imbalance of nutrients. Thus, there is a high incidence of nutritional
deficiency diseases., especially among the vulnerable groups of the population, that is, pregnant
women, infants, children and nursing mothers. Thus, directly or indirectly, nutritional deficiencies
account for a considerable part of the ill health among our population.

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