Also sometimes known as the “sunshine vitamin,” vitamin D is a fat-soluble hormone that your body can produce naturally. There are a number of forms of vitamin D, but the two most important ones are vitamin D-2 and vitamin D-3. Vitamin D-3, also known as cholecalciferol, is made by your skin naturally. Your body needs D-3 for things such as calcium absorption and bone strength, and it contributes to your overall health as well.
Some studies suggest that vitamin D-3 supplements may help treat the symptoms of seasonal affective disorder. Because vitamin D-3 is made by your body when it is exposed to sunlight, the theory is that vitamin D-3 supplements may alleviate some of the symptoms associated with depression from low sunlight exposure during the colder months. However, studies are inconclusive about this, and the standard treatment for seasonal affective disorder remains light therapy.
Maintaining Calcium Levels
Vitamin D-3 helps your body absorb calcium, an essential mineral for the production of healthy bones and teeth. Calcium is especially important during infancy and adolescence, and poor calcium absorption can lead to low calcium levels and poor bone health and development. Over long periods of time, low levels of vitamin D-3 can result in osteoporosis.
Some lab and population studies have shown that vitamin D may help reduce the risk of certain cancers. However, these studies are not definitive, and according to the University of Maryland Medical Center, the conclusions are still quite speculative. However, vitamin D-3 may help with reducing the liklihood of skin, breast and colon cancers, among several others.
Sources of Vitamin D-3
In addition to obtaining vitamin D from sun exposure, you can get the vitamin from some food sources. Dairy products -- such as cheese, butter and fortified milk -- all contain vitamin D. Fatty fish and oysters are also sources of vitamin D, as well as fortified breakfast cereals. Just remember that getting your daily vitamin D requirement from sun exposure may be difficult. Depending on skin color, where you live and season of the year, you may need from 45 minutes to three hours per week of sun exposure to make enough vitamin D. The sunlight needs to reach your face, arms, back and legs without any sunscreen blocking the rays.