Sunshine vitamin has numerous health benefits
By: Jessica Woodward, M.D.
It’s been a chilly winter, but even on the coldest of days, sunshine is always a welcome sight. It makes the landscape a little brighter and can make the frigid day seem less dreary. As it turns out, there are other benefits to sunshine as well.
Exposure to direct sunlight helps our bodies produce vitamin D, the only vitamin that doesn’t have to be consumed in food or supplements, although it can be acquired that way.
It’s been known since the early part of the 1900’s that vitamin D prevented and cured the bone disease, rickets. But current knowledge shows that health benefits of vitamin D are numerous.
Although it’s commonly known and classified as a vitamin, the active form of vitamin D is a steroid hormone. After vitamin D is created through exposure to sunlight or is consumed, the kidney and liver convert it into an active hormone form. This hormone controls calcium absorption, which helps the body build strong teeth and bones. It also helps maintain muscle strength.
Because vitamin D is needed to absorb calcium, a lack of vitamin D can be detrimental to your bones. It can cause you to lose bone mass, which can lead to osteoporosis and a risk of fractures, especially in the elderly.
The health benefits of vitamin D go beyond your bones and muscles. Low levels of vitamin D have been linked with arthritis, multiple sclerosis, auto immune diseases and certain internal cancers including colon, prostate, lung, ovary, kidney, pancreas and breast cancers.
Sunlight is one of the easiest and best sources for vitamin D. The ultraviolet rays from the sun trigger the natural synthesis of the vitamin. The body is efficient at making vitamin D from the sun, and it lasts twice as long as other sources such as fortified foods or supplements. In addition, there is no risk of overdosing from the sun. Sunlight will only produce as much vitamin D as your body needs.
Regular sunscreen blocks out vitamin D, so there is some controversy with sun exposure because of its link to skin cancer, specifically melanoma. The key for most people is brief, sensible sun exposure. This means about 10 minutes a day with 40 percent of the body exposed.
For persons with a high risk or history of melanoma, 10 minutes in the sun might be 10 minutes too many. Luckily, there are other sources for vitamin D. These include dietary sources and vitamin supplements.
Foods that are naturally high in vitamin D include salmon, tuna, catfish, sardines and eggs. Other foods that have been fortified with vitamin D include dairy products such as milk, yogurt, certain cereals and juices.
Current FDA recommendations for daily intake of vitamin D are 200 international units for people 50 and younger; 400 units for persons ages 51 to 70 and 600 units for those 70 and older. There is some evidence that higher intake may be warranted, but the jury is still out on this. Too much vitamin D can lead to toxicity. Before starting on any medication or vitamin supplement, you should check with your doctor to see what he or she recommends for your specific situation.
If you and your doctor decide that a vitamin D supplement might be beneficial for you, make sure that you choose one that is fortified with vitamin D3.
Dr. Woodward is a board certified family practice physician at Raiter Clinic.