Vitamin D is unique among vitamins in that it can be provided to your body through food or from exposure to the sun or tanning bed. Sunshine is a significant source of vitamin D because UV rays from sunlight triggers vitamin D synthesis in the skin. Vitamin D functions as an important hormone by sending a message to your intestines to increase the absorption of calcium by as much as 80%. Vitamin D is well known for maintaining normal calcium levels,1 but it is involved in so much more!

Vitamin D is essential for healthy bones. The main job of vitamin D is to regulate the body's use of calcium. It helps make the hormones that make sure calcium goes into bone and not into other tissues.

Hypovitaminosis D osteopathy, a collection of vitamin D deficiency symptoms, is a condition occurring when there isn't enough vitamin D to make the hormones that maintain healthy calcium balance.

Several diseases and health problems are symptoms of a poor supply of Vitamin D. The most familiar symptoms of inadequate Vitamin D are soft bone disorders. Called rickets in children, osteomalacia in adults, and osteoporosis in seniors, soft bone disorders indicate an inadequate supply of calcium to strengthen bones, which is usually a direct result of inadequate Vitamin D sources. This can lead to crippling deformations, easier bone fractures, and diminished bone density.

Vitamin D deficiency is common, particularly in children, pregnant women, breastfed babies, and anyone who stays indoors or covers their skin. It is important to treat and prevent deficiency to ensure good health, growth and strong bones. See your doctor if you think you are at risk of vitamin D deficiency, or if you have symptoms such as muscle or bone pains. Vitamin D deficiency is easily treated and prevented with vitamin supplements. Pregnant and breastfeeding women, breastfed babies, and other people at risk of vitamin D deficiency should take vitamin D supplements.

More than 40 percent of American adults have low blood levels of vitamin D, which people can get from foods such as milk and salmon as well as nutritional supplements. During nonwinter months, however, people can also get vitamin D from standing in the sun for a few minutes several times a week. That amount of exposure may seem trivial, but many dermatologists worry that any sun exposure may increase the risk of skin cancer and, more significantly, that encouraging some sun exposure will lead some people to overdo it.

It is easiest to understand this if you know where vitamin D comes from. Vitamin D is made in the skin with the help of sunlight ? this is the main source of vitamin D. It needs bare skin and direct sunlight (not through a window). People with darker skins will need more sun to get the same amount of vitamin D. Vitamin D is also found in certain foods: liver, some types of fish, and egg yolk. Some cereals or margarines contain added vitamin D.