Vitamin D has the following physiological functions:
1 to raise the body's calcium and phosphorus absorption, so that plasma levels of calcium and plasma phosphorus saturation level.
2, promote growth and bone calcification, the promotion of healthy teeth;
3, through the intestinal wall to increase the absorption of phosphorus and by increasing renal tubular reabsorption of phosphorus;
4, maintaining a normal blood levels of citrate;
5, to prevent the loss of amino acids through the kidneys

Vitamin D has the following physiological functions:
1 to raise the body's calcium and phosphorus absorption, so that plasma levels of calcium and plasma phosphorus saturation level.
2, promote growth and bone calcification, the promotion of healthy teeth;
3, through the intestinal wall to increase the absorption of phosphorus and by increasing renal tubular reabsorption of phosphorus;
4, maintaining a normal blood levels of citrate;
5, to prevent the loss of amino acids through the kidneys

Vitamin D is found in many dietary sources such as fish, eggs, fortified milk, and cod liver oil. The sun also contributes significantly to the daily production of vitamin D, and as little as 10 minutes of exposure is thought to be enough to prevent deficiencies. The term "vitamin D" refers to several different forms of this vitamin. Two forms are important in humans: ergonomically (vitamin D2) and cholecalciferol (vitamin D3). Vitamin D2 is synthesized by plants. Vitamin D3 is synthesized by humans in the skin when it is exposed to ultraviolet-B (UVB) rays from sunlight. Foods may be fortified with vitamin D2 or D3

Vitamin-D is the most essential vitamin for body . The rich supplement of Vitamin-D is Sun ( Natural Energy).
Acai Force Max

The best method for getting Vitamin D into your body is spending time outside in the sun. At least 10 to 15 minutes a day is a enough for a healthy serving of Vitamin D.

Hi Sunnygirl
Vitamin D is a great topic for the forum, and for the basics of Vitamin D you could check out the article titled "Nutrition 101: Vitamin D" here:
http://www.healthcastle.com/nutrition101_vitaminD.shtml
Many other related article links are also provided.
Give it a read.
Tracey

Vitamin D is one of the only vitamins produced naturally by the body. However, in order for the body to produce vitamin D, it has to be exposed to an adequate amount of sunlight. Generally, an hour per week is more than enough, but surprisingly, many people are still not exposed to enough sun to produce beneficial amounts of vitamin D.

Some milks have vitamin D added to help the absorption of calcium.