By Mary Kay Holloway, RDN, CSO, LDN, Community Cancer Center
Nutrition research can be like a jigsaw puzzle. We see certain pieces or groupings that seem to fit together, but they don’t make up the whole picture. It can be hard to know just where in the picture they fit or if they even belong in the same picture. This can easily be said of a vitamin that is getting a lot of notoriety these days, Vitamin D, aka the sunshine vitamin. Recent studies show how vital D is to the body. It aids in bone health, has been linked in protecting against certain cancers, such as colon cancer; prevents rickets; and helps immunity to name only a few. We know how vital it is to us, but how much and from what sources is the best?
There are three basic ways to get D into your life: diet, sun, and supplementation. When it comes to diet, D is a fat-soluble vitamin that is naturally present in very few foods, but it is added to others. Good food sources include wild-caught, cold-water, fatty fish; fortified milk; and some fortified foods. However, it is hard to get the required amount of vitamin D from these foods alone. Therefore, it is important to add other ways to meet your body’s need.
Vitamin D is called the sunshine vitamin because it is created in our body when our skin is exposed to sunlight. According to the National Institute of Health Office of Dietary Supplements Vitamin D fact sheet, the season, geographic latitude, time of day, cloud cover, skin melanin content, and sunscreen are among the factors that affect UV radiation exposure and D synthesis. It goes on to say that despite the importance of the sun to D synthesis, it is prudent to limit exposure of skin to sunlight. UV radiation is a carcinogen responsible for most of the estimated 1.5 million skin cancer cases and the 8,000 deaths due to metastatic melanoma that occur annually in the United States.
Lifetime cumulative UV damage to skin is also largely responsible for some age-associated dryness and other cosmetic changes. It is not known whether a desirable level of regular sun exposure exists that imposes no (or minimal) risk of skin cancer. However, 5–10 minutes a day in the sun may be all your body needs for adequate D.
Dietary supplements of D is the third way. This is available in two forms, D2 (ergocalciferol) and D3 (cholecalciferol). D3 may be more effective in raising our blood level and maintaining those levels than D2; however, D2 is used when rapid repletion is needed. Many of the supplements available on the store shelves contain D3.
The most important part of this article is this question: “Do you know what your blood level of Vitamin D is?” It is important that we know what our blood level of D is before we begin to guess at the supplement amount that is right for us.
Research is showing that many people are deficient or depleted of D. Ask your doctor to run a blood test to see where your D level is. You can go to www.vitamindhealth.org or www.vitamindcouncil.org for more information on responsible sun exposure and supplement use to keep your blood levels of D in a good range while we let the scientists continue to put the rest of the puzzle pieces in place.
The Community Cancer Center offers a variety of supportive and educational groups and programs, free of charge, to help patients and families cope with cancer and its effects. For more information, go to their website at www.cancercenter.org.
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