Minerals constitute 4% of the total body weight. Its elements are inorganic substances found in body tissues and fluids. They occur in foods as salts e.g. calcium , phosphorus , potassium , sodium , iodine , iron ,copper , molybdenum, sulphur , chlorine , magnesium , manganese. Its helps to build tissues , regulate body fluids or assist in various body functions. Unlike carbohydrates , fats and proteins , they do not furnish energy. They too like the vitamins are required in small quantities and are vital to body. They may be present in the body as organic compounds such as phosphoproteins , phospholipids , haemoglobin , thyroxine , calcium phosphate and as free ions. They should be supplied daily as they are excreted through the kidney the bowel and the skin. Sodium is the main electrolyte in the extracellular fluid and potassium is the main electrolyte in the intracellular fluid. These elements are not destroyed by heat , oxidation , acid and alkali. Since they are soluble in water , some loss occurs due to leaching when cooking water is discarded.
Classification of Minerals
- Major Minerals : Seven minerals are required in large amounts of over 100 mg/day. Calcium , phosphorus , sodium , chlorine , potassium , magnesium and sulphur.
- Minor Minerals : these are required in small quantities less than 100 mg/day. Iron , and manganese.
- Trace elements : a few micrograms to a few milligrams are required per day. Iodine , fluorine , zinc and molybdenum.
- It is the structural components of bones , teeth , soft tissues , blood and muscles.
- They act as enzyme activators.
- They regulate cellular oxidation.
- Necessary for clotting of blood.
- Maintain acid-base balance of body fluids.
- They regulate activity of nerves with regard to stimuli and contraction of muscles.
- They are constituents of vitamins.
- They help to utilize food by helping in the process of digestion.
- They control water balance by means of osmotic pressure and permeability of cell membranes. Sodium and potassium.