The Sunshine Vitamin

 

Vitamin D is often called "the sunshine vitamin" because the sun is the body’s main source of vitamin D. The skin produces a natural form of vitamin D from a form of cholesterol, called 7-dehydrocholesterol. Sunlight is key: the sun's UVB rays convert this cholesterol in the skin into a vitamin D3 precursor. These initial forms of vitamin D3 then pass their way through the liver and the kidneys, where they are converted into a form of vitamin D that can be used by the body.

Vitamin D plays many important roles in the body. While it is found in a few foods such as oily fish, red meat, and egg yolks, the sun is still our main source of vitamin D. There are a number of different factors that can result in vitamin D deficiency, with a lack of adequate sunlight being the main cause. 

Between being indoors more and using sunscreen more often some people who don’t get enough vitamin D from the sun can often benefit from taking a vitamin D supplement. But megadoses are not only unnecessary, they can be dangerous. Vitamin D is a fat soluble vitamin, meaning the body stores any excess in fat rather than disposing of it as it does with water soluble vitamins. Taking high doses can cause it to accumulate to unhealthy levels.

The best way to know whether or not to supplement and how much is to confer with your doctor. A simple blood test will reveal whether your vitamin D levels are adequate or not and then an appropriate supplemental dose can be recommended.

How much sun does the average person need to maintain healthy vitamin D levels? Not all that much. According a a study at King's College in London, just 5 minutes of unprotected mid-day sun exposure four times a week is plenty. If you have brown or black skin, make it 7 minutes.