Vitamin D: Let the Sun Shine?
For decades we have heard about the dangers of sun exposure. Ultraviolet (UV) rays from the sun cause damage to the skin leading to premature aging and increased risks of skin cancer. With strong messages from medical organizations, many people have increased their sun protection habits, such as daily sunscreen and avoiding the sun.Ideally, these changes have improved our health by decreasing cancer risk, but we are also blocking a major health benefit. In as little as 5-30 minutes twice a week, the sun’s UVB (a type of UV ray) rays can stimulate the Recommended Dietary Allowance of vitamin D (400-800 units.) And more and more research is showing vitamin D to be an important vitamin. Is the sun’s vitamin D benefit enough to outweigh its risks?
Vitamin DVitamin D
has stirred up interest in the medical community because of research that has shown that it has protective effects against heart disease, osteoporosis
, and several types of cancer, including breast
, and colon
cancers. The benefits of vitamin D have been well researched. The debate is now about where you should get your vitamin D.
Some of the highest sources of vitamin D are fish and fish liver oils. But Americans get the majority of their vitamin D from fortified foods like milk and orange juice. Even with fortified foods, it is difficult for the majority of people to get enough vitamin D through diet alone.
Vitamin D is available in supplement form, usually in a combination pill with calcium. An effective supplement would be able to increase blood levels of vitamin D. Vitamin D3 (cholecalciferol) is a preferred source of supplemental vitamin D. However, supplements do not provide anywhere near the amount of vitamin D that the sun can provide. High amounts of vitamin D supplementation have led to dangerously high levels of calcium in the body. Sun-created vitamin D, even at significantly higher levels, does not cause these problems.
The sun is believed to provide the majority of your vitamin D supply. But even the sun’s benefits have some inconsistencies. The summer sun can create enough vitamin D within 15 minutes for people with fair skin, but it may take 6 times longer in people with darker skin.UVB rays are also weak and can be easily blocked by clouds, smog, and glass windows. During certain times of the year, in far north and far south regions (like Washington state and Vermont), between November and February, the sun’s UVB rays do not even reach the Earth’s surface. There is far less or no production of vitamin D during these times of year. And of course, for some, the risk of skin cancer leaves the sun out as a reasonable source for vitamin D.