Low vitamin D levels have been linked to an increased risk of developing multiple sclerosis (MS), but a new study found that high doses of vitamin D did not help MS patients any more than low doses.

“We did not find added benefit from high-dose vitamin D over and above ongoing low-dose vitamin D supplementation," said study author Mark S. Stein of The Royal Melbourne Hospital and The Walter and Eliza Hall Institute of Medical Research in Parkville, Australia.

The six-month study published Oct. 25 in the journal Neurology involved 23 people with the relapsing-remitting form of MS. All of the participants received low-dose vitamin D (1,000 IUs daily) to prevent any vitamin D deficiency. Half of the participants also received high-dose vitamin D2 to elevate their blood vitamin D to high levels. The other half received a placebo high-dose.

Four of the 11 people taking the high-dose vitamin D, or 37 percent, had a relapse where their MS symptoms worsened during the study, while none of the 12 people taking only low-dose vitamin D had any relapses.

Stein noted that the study involved people who had MS for an average of six years. “It’s possible that studies of high-dose vitamin D at an earlier stage of MS may lead to different results,” he said.