Taking high-dose vitamin D daily helps reduce MS relapses

Taking high-dose vitamin D supplements for more than a year can significantly cut relapse risks and ease disability for people with multiple sclerosis (MS), according to a review of more than 30 clinical trials.

These benefits were observed in patients who added the vitamin to their standard disease-modifying therapies, though the supplements had to be taken long term to be effective.

Long-term supplementation with a mid-dose also led to fewer relapses, the data showed. In contrast, add-on high-dose vitamin D taken for less than one year showed no significant differences.

‘Vitamin D supplementation as an adjuvant therapy may reduce relapse and disability progression, with a favourable safety profile,’ researchers wrote.

MS is a series of inflammatory attacks that damage the brain and spinal cord, and it’s well established that vitamin D can influence disease onset and progression.

Studies have found an association between low vitamin D blood levels and a higher risk of developing MS, while other research suggests that people with lower vitamin D levels experience more frequent relapses and faster disability progression.

As a result, both the American Academy of Neurology and the European Academy of Neurology have incorporated vitamin D as an adjuvant therapy in their MS treatment guidelines.

However, those guidelines address vitamin D supplementation only in broad terms and do not provide specific recommendations on appropriate doses or treatment duration. This has limited the practical application of vitamin D in clinical settings, according to the researchers.

To address this, researchers in China pooled the results of published clinical trials to provide more detailed, evidence-based guidance on the optimal vitamin D regimen for MS patients.

‘This approach enables a deeper understanding of the role of vitamin D and offers evidence-based guidance for vitamin D therapy in MS patients to support clinical decision-making,’ the team wrote.

Pooled data from all studies showed that vitamin D supplementation for more than one year was associated with a 20% reduction in relapse risk and a modest but significant improvement in disability scores (indicating less severe symptoms) compared with a placebo.

Long-term vitamin D supplementation was also associated with a 49% lower risk of having lesions with active inflammation and a significant reduction in total lesion volume. Relapse rates, however, were not significantly different between the groups.

Vitamin D supplementation over the short term did not significantly affect relapse risk, disability levels, or relapse rates.

In terms of safety, vitamin D supplementation did not increase the risk of serious adverse events, which included outcomes such as death, hospitalisation, pregnancy complications, and kidney stones.

‘Further large-scale [randomised controlled trials] are required to validate the efficacy and safety of different vitamin D dosing regimens and explore personalised therapeutic approaches based on biomarkers,’ the researchers concluded.

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