(HealthDay News) – Month of birth affects the risk of multiple sclerosis (MS), according to research published online Nov. 14 in the Journal of Neurology, Neurosurgery & Psychiatry.

Ruth Dobson, MRCP, from the Queen Mary University of London, and colleagues reviewed the literature and conducted a meta-analysis based on published data from 151,978 MS patients.

The researchers found that there was a significant excess of MS risk in those born in April (observed:expected, 1.05; P=0.05) and reduction in risk in those born in October (0.95; P=0.04) and November (0.92; P=0.01). In addition, using a conservative analysis of 78,488 patients, the researchers observed an excess MS risk in those born in April (1.07; P=0.002) and May (1.11; P=0.0006), and a reduced risk in those born in October (0.94; P=0.004) and November (0.88; P=0.0002). For December, a significant relationship between latitude and observed:expected ratio was found along with borderline significant relationships in May and August.

“Through combining existing datasets for month of birth and subsequent MS risk, this study provides the most robust evidence to date that the month of birth effect is a genuine one,” write the authors. “This finding, which supports concepts hypothesized some years previously, surely adds weight to the argument for early intervention studies to prevent MS through vitamin D supplementation.”

Several authors disclosed financial ties to the pharmaceutical industry.

Full Text (subscription or payment may be required)