One dose of vitamin D boosts TB immunity

NEW YORK, Aug 3 (Reuters) In healthy people who have been exposed to tuberculosis, a single oral dose of vitamin D enhances their immunity against this bacterial infection.

''Vitamin D was used to treat tuberculosis in the pre-antibiotic era,'' Dr Adrian R Martineau, of Queen Mary's School of Medicine and Dentistry, London, and colleagues note. Studies that have evaluated the effects of vitamin D supplements on tuberculosis immunity have not been performed, they point out in their report, published in the American Journal of Respiratory and Critical Care Medicine.

Martineau's group therefore conducted a clinical trial in which they assigned 192 healthy adults who had been exposed to tuberculosis to receive a single oral dose of 2.5 milligrams of vitamin D or a placebo.

Of the 192 subjects, 43 were lost to follow-up and 18 were excluded, so that 131 participants were included in the analysis of primary outcome. Of these, 64 received placebo and 67 received vitamin D. After 6 weeks, the subjects were tested for evidence of Mycobacterium tuberculosis.

The researchers found that the vitamin D supplement significantly enhanced the subjects' immunity to M tuberculosis compared with those who received the placebo.

Based on these findings, Martineau's team suggests that ''clinical trials should be performed to determine whether vitamin D supplementation prevents reactivation of latent tuberculosis infection.'' REUTERS SZ BD0849