Genetically reduced vitamin D levels were “strongly associated” with increased risk of multiple sclerosis (MS) in a study of European populations.
The researchers used patients’ levels of 25-hydroxyvitamin D (25OHD) to determine genetically reduced vitamin D levels. They conducted a Mendelian randomization study “to describe the effect of genetically lowered 25OHD on the odds of MS in the International Multiple Sclerosis Genetics Consortium study,” which comprised 14,498 MS patients and 24,091 healthy controls.
“Each genetically determined one-standard-deviation decrease in log-transformed 25OHD level conferred a twofold increase in the odds of MS (95% confidence interval; 1.7-2.5; P = 7.7 X 10-12; I2 = 63%, 95% CI: 0-88%),” according to Dr. J. Brent Richards of McGill University, Montreal, and his colleagues. This provided “strong evidence” that vitamin D played “a causal role” in the patients’ susceptibility to MS.
“Whether vitamin D sufficiency can delay, or prevent, MS onset merits further investigation in long-term randomized controlled trials,” the researchers wrote.
Read the full study in PLOS Medicine (doi:10.1371/journal.pmed.1001866).