Vitamin D

Vitamin D is not really a vitamin, but one of the oldest prohormones. Vitamin D for humans is obtained from sun exposure, food and supplements.

The main function of the vitamin D is to help regulate absorption of calcium and phosphorus from the intestine and the deposition of calcium in the bones.  Working with other hormones, the vitamin D closely regulates blood calcium so that appropriate amounts of it will be supplied to all cells.
Vitamin D ensures normal development of skin, colon, prostate, ovary, and breast cells, in turn reducing cancer risk in these sites.

Vitamin D may also reduce the risk of tooth loss by preventing the inflammatory response that leads to periodontal disease.


Rich sources are sardines, salmon, tuna, fortified milk and yogurt, cereals. It can be also found in egg yolks, butter, beef liver, and margarine.

Too much vitamin D taken regularly can create problems such as calcium deposits in the kidneys and other organs, weakness, loss of appetite, diarrhea, vomiting, mental confusion, and increased urine output. Vitamin D toxicity does not result from tanning in the sun too long because the body regulates the amount made in the skin.

Low levels of vitamins D are associated with weakened immune system, increased mortality, premature aging, osteomalacia, cardiovascular diseases, multiple sclerosis, increased cancer risks.