Vitamin D is a fat-soluble vitamin essential for normal growth of teeth and bones.

When vitamin D is acquired from the diet or produced in the skin it is biologically inactive. It must be metabolized by the liver to produce 25-hydroxyvitamin D₃. However, this compound is also biologically inactive under physiological circumstances and must be activated by the kidney to produce the final vitamin D hormone, 1,25-dihydroxyvitamin D₃.

Very few foods contain vitamin. Some good sources however, include dandelion greens, oatmeal, salmon, sweet potatoes and last but not least fish liver oils. Cod liver oil for example has been recognized for many years as a great source of vitamin D. While some fortified foods contain vitamin D, the best source of vitamin D is exposure to sunlight or ultraviolet irradiation as this will cause the skin to produce the vitamin naturally. During the winter months the skin produces insufficient amounts of vitamin D. Unless these amounts are replaced by a dietary source one can become deficient in the vitamin.

In growing animals, a vitamin D deficiency results in a disease known as rickets. In adult animals, the deficiency leads to a disease similar to rickets known as osteomalacia. The most serious condition associated with vitamin D deficiency is convulsions known as hypocalcemic tetany, which result from the low-blood calcium. Deficiencies of vitamin D in moderate amounts may be linked to osteoporosis, especially in older individuals.

Vitamin D has been a recommendation among experts in the prevention and treatment of osteoporosis. Depleted calcium is the primary cause of osteoporosis but supplementing with calcium alone however will not solve this problem as vitamin D is needed for calcium to be properly absorbed and utilized. Supplementing with vitamin D without calcium is ineffective as well.

Vitamin D also plays an important role in the prevention of cancer, particularly colon cancer. Risk of developing this type of cancer is increased with Vitamin D deficiency.

The best method of obtaining a good source of vitamin D is natural sunlight. Exposure of the face and arms to the sun for just fifteen minutes three times a week is an effective way to guarantee adequate amounts of vitamin D in the body. Be sure not to spend excessive amounts of time in the sun if you burn easily.

* Important note: Cholesterol-lowering drugs, antacids and steroid hormones interfere with absorption of vitamin D. The recommended doses are for those over age 18. Always check herb and vitamin use with your child’s health care practitioner prior to administering them.