Virtually all the phosphorus (P) in the body is combined with calcium in the bones and teeth. About 20% is involved in organic and other compounds. It is vital for forming the structure of the bones, and plays a part in electrical conduction in nerves. Compounds containing phosphorus are usually involved in the transfer of energy when carbohydrates, protein and fat are broken down. The amount of phosphorus in the body is controlled by parathormone, a hormone produced by the parathyroid glands in the neck.
The amount of phosphorus in the blood can be measured and this will indicate the level of phosphorus in the entire body. The normal range is from 0.9 to 1.5 mmol/L (3-4.5 mg/100 mL). High levels may indicate poor kidney function, an underactive parathyroid gland or excess vitamin D in the body. Low levels may be due to an overactive parathyroid gland, lack of vitamin D, rickets, osteomalacia and other diseases of the kidney and bones. Phosphorus levels can drop temporarily after a large meal. The concentration of phosphate in the blood is influenced by parathyroid gland function, intestinal absorption of phosphorus from food, kidney function, bone metabolism and nutrition.
Phosphorus is added to numerous non-prescription vitamin and mineral supplements. It can have medicinal uses in treating a nutritional deficiency, hyperparathyroidism, multiple myeloma, some form of rickets and bone cancer. The recommended daily dose is 1000 mg. but higher doses are used in treating the diseases listed above. It is safe to use in pregnancy, breastfeeding and children, but must be used with caution in kidney disease. If high doses are used, regular blood tests to check the balance of all minerals in the blood are necessary. Excessive amounts may cause diarrhoea, calcium deposits in tissue, kidney stones and phossy jaw.