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By Pat Sinclair One of the key goals of the green living movement is to reduce pollution and the obvious damage it is doing to our environment. One lesser known effect of air pollution is decrease in sunshine, which results in our bodies not being able to manufacture vitamin D. Vitamin D is called the sunshine vitamin because our bodies manufacture it from a form of cholesterol when skin is exposed to the ultraviolet rays of the sun. In the south, ten to 15 minutes of sunshine 3 times a week produces enough vitamin D in the skin, but with increased use of sunscreen and heavier air pollution, experts feel that vitamin D supplements are becoming necessary almost everywhere. In the northern U.S. the level of the sun is too low to provide enough ultraviolet rays to produce adequate levels of vitamin D from November to February. People living in areas above a line drawn roughly from northern California to New England are included in this group. Generally sunscreen with a protection factor of 8 prevents the manufacture of vitamin D under the skin, but for exposure longer than 10 to 15 minutes, sunscreen is essential to prevent skin cancer. With these limits it’s important to include good sources of vitamin D in our diets. Vitamin D helps prevent rickets in children and osteoporosis in adults. Bone is constantly lost and rebuilt, but as we age it becomes more difficult for the body to rebuild. Once this delicate balance is upset, bones are more fragile and easily broken in falls especially after menopause. Vitamin D helps maintain appropriate levels of calcium and phosphorous in the blood and improves the absorption of calcium into bones. Recent studies have also found higher blood levels of vitamin D correlated to lower risk of heart disease, diabetes, and breast and colon cancers. It may also help protect from autoimmune diseases such as Crohn’s disease, multiple sclerosis and rheumatoid arthritis. These recent findings have led to a call for more research as we discover more and more roles vitamin D plays in the body. In the United States since the 1930s most milk has been fortified with vitamin D and rickets in children has been almost eliminated. However a decline in milk consumption along with increased bottled water and soft drinks consumption is now creating low levels in children. Current recommended levels of vitamin D are considered low by many health professionals but more study is needed before there will be any changes. Recommended levels at this time are: • Age 19-50: 200 IU (international units) • Age 51-69: 400 IU • Age 70 and older: 600 IU Dark-skinned people and adults older than 50 are thought to have a higher risk of vitamin D deficiency because the ability of their skin to convert vitamin D to its active form is diminished and kidney function may also be reduced. Milk is rich in this amazing vitamin but most other good food sources have been fortified. Milk, fortified cereals, margarine, egg yolks and some fortified fruit juices are the best dietary sources. Dairy products can be good sources if they have been made from vitamin D fortified milk but this can be hard to determine. Even if you concentrate on eating foods fortified with vitamin D it is hard to obtain adequate amounts without sunshine or supplements. Most multivitamins contain 400 IU’s including “silver” versions for older adults. More research is needed into the roles vitamin D plays in our bodies but it’s becoming apparent that higher levels in the blood have positive effects on health. Experts suggest a daily multivitamin in addition to adding fortified foods to our diets. Find more information and recipes at www.PatCooksandBakes.blogspot.com.
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The Healthy Table