Vitamin D is important in a number of ways. It is necessary for your body to absorb calcium. And when calcium and phosphorus are rich in your bloodstream, they are deposited in your bones. Your bones become mineralized and harder as a result. This gives you protection from osteoporosis, a disease which strikes many older adults, especially women.
Vitamin D is also thought to play a role in reducing the risk of skin, breast, colon, pancreas, and prostate cancer.
Too little of the vitamin can lead to muscle weakness, fractures, autoimmune diseases, infectious diseases, and cardiovascular diseases. It can also play a role in the development of type 1 diabetes.
In the July issue of the “New England Journal of Medicine,” a report was published detailing the widespread vitamin D deficiency in our population — as much as one billion people!
The report said that people who live in higher latitudes are more likely to be vitamin D–deficient. The sun’s rays in northern latitudes are at too much of an angle to produce vitamin D in the skin.
The report states that only 10% of calcium and 60% of phosphorus is absorbed in the body when there is no vitamin D to help.
Michael Holick is the director of the General Clinical Research Center at Boston University School of Medicine and director of the Bone Healthcare Clinic at Boston Medical Center. He collected the findings for the report.
Holick says he would like to see the current recommended intake for vitamin D increased from 800 to 1,000 international units (IU) of vitamin D3 per day.
You can get some vitamin D through your diet. You need to eat oily fish frequently. Liver, shrimp, and eggs also contain some vitamin D. But, Horlick says, for most people “sensible sun exposure and/or supplements are required to satisfy the body’s vitamin D requirement.”
What is a sensible amount of sun exposure to meet your requirements for vitamin D?
15 minutes of sun exposure to the face, arms, hands, or back twice a week should be enough. Keep in mind that cloud cover can cut the energy of UV rays in half. Shade also reduces the energy by as much as 60%. Pollution can affect the sun’s rays as well, making them less effective for synthesizing vitamin D.
Don’t wear sunscreen for your two vitamin D sessions in the sun. Sunscreen with an SPF of 8 or greater will block the rays that produce vitamin D. It is definitely still important to use sunscreen — just put it on after your 15- minute sessions.