Mineral Salts

The body of every mammal contains many mineral elements which play specific roles in metabolic processes. They are ingested in the form of salts (ions) in many foods. Calcium and phosphorus are obtained from the diet in the form of calcium phosphates. Once ingested, the salts ionises, providing the body fluids with free calcium and phosphorus ions. The calcium takes part in blood-clot formation. It is also needed for the normal functioning of cell membranes, for muscle contraction, and strengthening bones and teeth. Phosphorus, as phosphate ions, is needed for the synthesis of high energy compounds, including adenosine triphosphate (ATP) and the nucleic acids RNA and DNA. As calcium phosphate, it is needed for the formation of strong bones and teeth. Milk, fist and whole grain cereals are rich in calcium and phosphorus. Compounds of potassium are essential for the proper functioning of the nervous system, especially nerve impulse transmission. Sodium chloride (table salt) provides the body with sodium (Na +) and chloride (Cl-) ions. Chloride ions activate salivary amylase which catalyses starch digestion during chewing. It also a constituent of hydrochloride acid present in gastric juice. Sodium ions are important in the functioning of all cell membranes and in the transmission of nerve impulses. Iron is present in foods including liver, green vegetables, eggs and kidney. It forms haemoglobin in red blood cells (erythrocytes). Its absence causes anaemia due to a reduction in the oxygen –carrying capacity of blood. Iodine is essential for the proper functioning of the thyroid gland. A deficiency of iodine causes simple goitre. A deficiency of iodine causes simple goitre. It is present in seafoods and may be added to household salt where there is insufficient iodine in locally grown vegetables.