Vitamin D Linked to Lower Multiple Sclerosis Rates


NEW BENEFITS FROM VITAMIN D keep piling up in the scientific literature, and the latest could represent an advance in preventing a crippling neurological condition affecting 350,000 Americans-multiple sclerosis (MS). In research published in the Journal of the American Medical Association, scientists reported a significant association between high blood levels of vitamin D and reduced risk of multiple sclerosis. The relationship was seen only among whites, however, and not in blacks or Hispanics.

In the prospective, nested case-control study, Kassandra L. Munger, MSc, and Alberto Ascherio, Mg, DrPH, of the Harvard School of Public Health and colleagues matched each of 257 MS patients to two controls by age, sex, race/ethnicity and dates of blood collection. The subjects were drawn from more than 7 million US military personnel who have serum samples stored in the Department of Defense Serum Repository. Multiple sclerosis cases were identified through Army and Navy physical disability databases and diagnoses were confirmed by medical record review.

The researchers found that among whites, there was a 41% decrease in MS risk for every 50-nanomoles per liter increase in serum 25-hydroxyvitamin D, a marker for vitamin D in the body. The MS risk was highest among individuals in the bottom fifth of vitamin D levels and lowest among those in the fifth with the most vitamin D-62% lower than those with the least serum vitamin D. The inverse relation with MS risk was particularly strong for those whose blood had been sampled before age 20.

Among blacks and Hispanics, who had lower 25-hydroxyvitamin D levels than whites, no significant associations between vitamin D and MS risk were found. The smaller sample size of black subjects and their substantially lower 25-hydroxyvitamin D levels "may have reduced the power to detect an association in this group," the authors note.

More research is needed to confirm whether vitamin D actually reduces the risk of multiple sclerosis, Dr. Ascherio cautioned in a Reuters news service interview. But he added, "lf it is true, the implication could be enormous for MS prevention."

The Story of D
Recent studies have linked higher levels of vitamin D in the body to prevention of various types of cancer and improved lung health, while also emphasizing vitamin D's crucial role, in tandem with calcium, in bone health. The recommended daily dietary intake of vitamin D varies by age: 200 IU for ages 19 to 50, 400 IU for ages 51 to 70, and 600 IU for ages 70 and older. But many experts now believe those levels are too low, especially for order adults. Tuffs' Bess Dawson-Hughes, MD, suggests older adults need 800 IU of vitamin D daily. Your body naturally produces vitamin D from sunlight; Dr. Dawson-Hughes recommends getting up to 15 minutes of sun before applying sunscreen. Vitamin D is also found in foods such as fortified milk and juice and fatty fish. But it's difficult to get enough vitamin D from natural sources alone, especially during the winter in northern latitudes, so you may want to consider supplements.

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