Because it leads to the prevention of rickets in children, vitamin D was originally placed in the category of "vitamins," but it is actually a natural hormone which serves many valuable health functions. It helps control blood pressure and bone density, regulates mood, enhances muscle strength and immune function and stimulates hair growth. In fact, scientists have found that nearly every cell in the human body carries vitamin D receptors.

It is assumed that vitamin D is plentiful in the diet. However, very few foods contain natural vitamin D, and only a few of them, like dairy products, are fortified with this important vitamin. Most natural vitamin D comes from ultraviolet B radiation found in the sun's rays which is why it has been coined "the sunshine vitamin." Sunshine converts molecules found under the skin into a form of vitamin D that travels through the bloodstream to the liver and kidneys. Here it takes on the job of regulating calcium levels and storing it in the bones.

Humans can synthesize up to 50,000 IU of vitamin D in the skin per day, but roughly 20,000 IU is a more common amount. There are several problems however with sole dependence on the sun for vitamin D. According to experts, it is impossible in the wintertime for those living above the 37th parallel to get adequate amounts of natural vitamin D from sunshine. Since this represents a majority of Americans, many believe that vitamin D3 (or cholecaciferol) supplements may be the answer.

The recommended daily allowance of 600 IU for vitamin D3 is only adequate to prevent rickets. Experts are now calling for higher recommended daily amounts to maximize this beneficial hormone. A Finnish study found that giving infants a natural dietary supplement of 2,000 IU per day of vitamin D for one year cut the risk of Type 1 diabetes by nearly 80 percent, and this remained in effect for 30 years! These results have proven to be as reliable as some types of vaccine.

In addition to increased risks of the developments of Type 1 diabetes and rickets, a deficiency of vitamin D can also prevent children from reaching their full height and attaining full bone mass. For adults, the effects are less overt. Vitamin D deficiency can reduce bone mineral density and aggravate osteoporosis. It can also increase the risks of fracture and cause muscle weakness, aching bones and muscle discomfort.

The pairing of deficiency and decreased exposure to the sun have also been shown to raise the risks of many types of cancer, rheumatoid arthritis, multiple sclerosis and type I diabetes. This pairing has also been linked to the development of type II diabetes and schizophrenia.

Vitamin D appears to be necessary for proper functioning of the human body. Therefore, vitamin D3 should be integrated into all daily routines for good health. This natural dietary supplement can be found in your local health food store or through online, health supplement websites.