Back grey_arrow_rt.gif
Low Vitamin D Increases Risk of Pediatric MS
  MedPage Today
Published: October 16, 2010
Action Points
* This study was published as an abstract and presented at a conference. These data and conclusions should be considered to be preliminary until published in a peer-reviewed journal.
* Note that the HLA-DRB1*15 allele and vitamin D level are independently associated with MS diagnosis following acute demyelination.
* Note also that since vitamin D status can be modified, further study is thought to be justified to determine whether improving vitamin D status in early childhood will reduce MS risk.
GOTHENBURG, Sweden -- Low serum vitamin D at the time of a first demyelinating event increases the risk of subsequent multiple sclerosis (MS) in children, according to a new study.
Of 208 children under age 16 who experienced an acute demyelinating episode, 41 subsequently received a diagnosis of MS an average of eight months following their first symptom. Those with MS had an average serum vitamin D level of 52 nmol/L, versus 66 nmol/L for those remaining without an MS diagnosis, according to Heather Hanwell, MSc, a PhD candidate in the Department of Nutritional Science at the University of Toronto.
The result extends the well-known connection between vitamin D and MS to pediatric MS cases, and, by placing deficiency so close to onset, strengthens the argument that vitamin deficiency plays a causal role in MS. The study was presented here at the European Committee for Treatment and Research in Multiple Sclerosis (ECTRIMS) meeting.
MS risk was also influenced by the HLA-DRB1*15 allele, previously shown to increase MS risk in adults, but there was no interaction detected between the gene and the vitamin, Hanwell said.
The data came from a longitudinal study by the Canadian National Pediatric Demyelinating Diseases Network, a collaborative effort to understand pediatric multiple sclerosis and other demyelinating diseases.
The network enrolls children who have developed an acquired demyelinating syndrome (ADS), "very similar to the CIS [clinically isolated syndrome] that we talk about in adults," Hanwell said. "At least a quarter of children with ADS go on to develop MS."
"Several lines of evidence point to a window of susceptibility early in life," from the prenatal period to as late as age 15, she said, during which environmental risk factors may act to increase subsequent risk of MS. In this study, "we are able to capture factors at or near the time those factors are acting."
The children in the study were enrolled from 23 sites across Canada. Blood samples were taken within 40 days of the demyelinating episode, and patients were followed regularly afterward for occurrence of a second episode and potential diagnosis of MS.
While MS patients were older than non-MS patients, and older children have lower vitamin D levels, the difference in vitamin D levels between the groups remained significant even after correcting for age.
Both groups had less vitamin D than they should, Hanwell noted. "Seventy-five nanomoles per liter is considered a conservative cutoff for vitamin D deficiency. These children are, on average, insufficient." One hundred nmol/L "is considered a possible therapeutic target for MS," she said.
There was also a dose response. Those in the highest quartile, above 81 nmol/L, had one quarter of the risk of subsequent MS outcome, compared to those in the lowest quartile.
The hazard ratio per nanomole was small, only 0.98, but, Hanwell said, "that 2% risk is actually quite meaningful," because it adds up. An increase of 10 nmol/L, for instance, would amount to a 20% risk reduction.
Alberto Ascherio, MD, DrPH, of Harvard School of Public Health, commented, "I think this is interesting and important, because it is a look at vitamin D levels shortly after the acute episode. These data do support an effect from vitamin D, even though they are not fully prospective."
"If vitamin D is, in fact, causal, it would be pretty dramatic, since over 80% of young adults have serum levels of under 100," he said. The risk of toxicity from supplementation is low, and the established benefits on other conditions are high. "Two hundred units per day would possibly be sufficient in most patients."
Vitamin D can't explain everything in MS, he said. "But it is time to consider a very large randomized trial," involving hundreds of thousands of young people over several years, he suggested.
Hanwell reported no disclosures.
Ascherio reported no disclosures.
Primary source: European Committee for Treatment and Research in Multiple Sclerosis
Source reference:
Hanwell H, "HLA-DRB1*15 and vitamin D status at first demyelinating episode are independent risk factos for MS in children" ECTRIMS 2010.
  icon paper stack View Older Articles   Back to Top