Minerals :-

Calcium

Among minerals, Calcium is present in the highest amount in the body mostly in the skeleton. Calcium is essential for the formation of bone and teeth, for clotting of blood, contraction of heart and muscle etc. A deficiency can cause 'Osteoporosis' in which decalcification of bone occurs. Even minor accidents can cause fractures. In children, a deficiency can cause a decreased rate in growth. Small fish eaten along with bones, skim milk powder etc are excellent sources and milk, milk products like curd, sesame seeds, ragi, green leafy vegetables like carrot leaves, drumstick leaves etc are other good sources. The daily recommended allowances for calcium is Adults 400-500mg, children between 400- 700 mg.

Iron

A greater part of the Iron in the body is present as Haemoglobin. Iron deficiency causes anaemia and is widely prevalent among children, adolescent girls and expectant and nursing mothers. Cereals are the most important sources of iron for Vegetarians and the other important sources are legumes, green leafy vegetables and jaggery. Meat, fish and eggs are also important sources of iron. The daily recommended allowances for iron is Adults 20-30mg, children between15-20 mg, pregnant and nursing women need more iron.

Iodine

Iodine is a constituent of thyroxine, the active principle of the thyroid gland. The thyroid gland plays an important role in energy metabolism and in the growth of the body. A deficiency can cause enlargement of thyroid, resulting in the disease called goitre. In children, severe iodine deficiency may result in serious retardation of growth known as cretinism. Iodine requirements for adults are about 0.15 to 0.2 mg daily and for infants and children 0.05 to 0.10 mg daily. This requirement is normally supplied by a well balanced diet and by drinking water except in mountainous regions where the food and water is deficient in iodine. Crude common salt prepared from sea water and sea fish are good sources.

Sodium Chloride (Nacl)

All minerals except Sodium Chloride (Nacl) are usually present in sufficient amounts in a well - balanced diet. Sodium chloride is the only mineral which is taken in more or less pure form in addition to the amount present in natural foods. Salt taken in food is the source of Nacl. The requirements depend on the climate and occupation. People doing heavy work in hot humid climates need more Nacl. A deficiency can cause heat cramps- intense and painful contractions of skeletal muscle. But consumption of excessive amounts of Nacl causes Oedema in protein deficiency and increases blood pressure in hypertension. Foods of animal origin contain more Nacl than those of Vegetable origin. The daily requirements for tropical climates are Adults 10-15 (light work), 20-25 (hard work) and children 5-10g/day.

Potassium

The adult human body contains about 250g of potassium which is present almost entirely in the cells of different tissues, muscles, etc. Only small quantities are present in the extra cellular fluid. Potassium is the major basic of ion of the body cells. The functions of potassium are : Regulation of pH of cell contents, Regulation of the osmotic pressure of cell contents and Potassium ion increases the relaxation of heart muscle which is antagonized by calcium ion. Potassium deficiency causes weakness and muscular paralysis. But Consumption of excessive amounts of potassium also causes the similar symptoms. Deficiency seldom occurs as potassium is present in abundance of foods.