B I N A R A G A . I N F O

Vitamin D (Calciferol)

Vitamin D is a fat-soluable vitamin, and it is essential in the proper absorption and metabolism of calcium and phosphorus; and for the formation of bones and teeth. There are two forms of vitamin D in nature, vitamin D2 (also known as calciferol or ergocalciferol) and vitamin D3 (cholecalciferol).

Our bodies manufacture vitamin D3 from the action of the sun on our skin. It then slowly enters the blood stream and is transported to the liver. In the liver it is converted into yet another form of vitamin D and then transported to the kidneys, where it is stored for future use. Most people can make all the vitamin D they need by being in the sun for a few minutes each day, or by consuming milk fortified with vitamin D.

Vitamin D is particularly important during times of growth; and therefore for babies, children, and during pregnancy and lactation. Post-menopausal women also need adequate vitamin D to help prevent osteoporosis. Children who receive insufficient vitamin D may develope rickets or other skeletal deformities, as well as malformed teeth. Adults may suffer from osteomalacia (bone softening). Symptoms of deficiency include muscle twitching, cramps and convulsions. If you are elderly or housebound and you feel that you do not receive enough vitamin D, you may need a small oral supplement - NO MORE THAN 10 micrograms per day, unless prescribed by a doctor. Note: 10 micrograms is equal to 400 IU (international units).

As with all fat-soluable vitamins, prolonged intake of megadose supplements is dangerous (especially in children). Symptoms of toxicity include nausea, weakness, excess urination, constipation, kidney damage, hypercalcaemia - calcification of the soft tissues of the body (including the heart), and kidney failure which can lead to death. None of the plants eaten by humans contain vitamin D. The only signifigant food sources of vitamin D are fish liver oils and fatty fish such as herrings, mackerel, and salmon. Some milks and powdered milks are fortified with vitamin D. Very small amounts of vitamin D are supplied by table margarine, butter, eggs, oysters, beef liver, bacon, and cheese.