Newsletters: May - June 2008

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Let the Sunshine In

Natural Times-May/June 2008

By Sandy Beck

For several years Dr. Ness, our family doctor, has advised me to take a calcium and vitamin D supplement to fortify my bones. I like Rainbow Light’s Food-Based Calcium (500 mg) with Magnesium (250 mg) and Vitamin D3 (200 IU) and have been taking three tablets a day, one with each meal.

Recently blood tests taken for my annual physical exam indicated low blood levels of vitamin D.

Current U.S. recommendations for daily vitamin D intake call for 200 IU for children and adults up to age 50 years, 400 IU for those aged 51–70 years and 600–800 IU for those older than 70 years.

But there is increasing evidence that these recommendations are probably too low. Many doctors are advocating taking higher doses in the form of supplements and moderate, unprotected sunshine.

Fifteen or twenty minutes each day of unprotected sun can fulfill most of our vitamin D needs. But because of the risks of skin cancer and damage (wrinkles), I slather on sunscreen and wear a big hat.

Those at highest risk for vitamin D deficiencies are the elderly (whose skin is less effective at converting the vitamin), obese (the vitamin is stored in fat), dark skinned and exclusively breast-fed infants.

Recent studies have shown that vitamin D, which has long been touted as having an important role in forming strong bones and has been added to milk and orange juice, is important for a myriad of other reasons.

In controlled studies, intakes of 400 IU per day showed no “appreciable reduction in fracture risk,” but “trials using 700 to 800 IU found less fracture incidence” resulting from falls.

A large number of studies in people have linked low vitamin D blood levels to an increased risk of several types of cancer, including lymphoma and cancers of the prostate, lung and, ironically, the skin. The strongest evidence is for colon cancer.

A study of non-Hispanic whites found a 75 percent lower risk of diabetes among those with the highest blood levels of vitamin D.

An article in the February 2007 Family Practice News, links low vitamin D levels with not only low bone density and osteoporosis but also with sarcopenia or degenerative loss of muscle mass and strength. Both of these conditions set the scene for increased falls and fractures.

Muscular weakness also may contribute to overactive bladder problems. Women who have high vitamin D blood levels have shown the lowest incidence of this condition.

The burning question is how much vitamin D is enough and how much is too much?

Dr. Henry W. Lim, chair of the dermatology residency program at Henry Ford Hospital, Detroit, wrote that vitamin D intoxication can occur when daily doses exceed 10,000 IU. Dr. Ness advised me to take 4,000 IU per day. He takes 6,000.

Not one for swallowing big tablets, I was happy to discover KAL D-3 2000 IU chewables, a tiny and tasty cinnamon-flavored tablet. This is a vitamin supplement I can live with.