How vitamin D affects the immune system in MS

Dr Wei Yeh

Alfred Health and Monash University, VIC

| Better treatments | Immunology | Scholarship | 2020 | Investigator Led Research |


MS is one of the most common neurological causes of disability among young adults. Living further away from the equator is associated with less exposure to UV from the sun and less vitamin D production, and is also linked to a higher rate of MS. These and other findings support a significant role for vitamin D in the development of MS. Dr Wei Yeh aims to determine the effects that vitamin D has on immune cells in people with MS, and how this is different to people without MS. This will shed further light on the role of vitamin D in MS risk and will help determine ways to prevent the development of MS.

Additionally, Dr Yeh will also investigate factors that might influence the risk of relapses during pregnancy. Previous studies have shown a reduced risk of relapse during pregnancy. Dr Yeh will use data from MSBase, a large international registry of people with MS, to find factors that predict relapse in pregnancy. These findings will help guide what to do in the clinic to minimise the chances of a relapse during pregnancy.

Project Outcomes

Dr. Wei Yeh's investigations continue to unravel the relationship between vitamin D and MS, focusing on how it impacts the immune system in people with and without MS.

In one study, they analysed the levels of genes in immune cells from both people living without MS and people living with MS who were untreated. Among the people living without MS, certain genes in special immune cells, known as CD4+ and CD8+ T cells, were linked to vitamin D levels, influencing immune and cellular processes. Interestingly, in CD4+ T cells of people living without MS, vitamin D levels correlated with genes close to MS risk, suggesting a potential connection between vitamin D, immune cells, and MS risk. However, responses to vitamin D seemed diminished in those with MS compared to those without MS, hinting at differences in how vitamin D interacts with the immune system in people living with MS.

Regarding vitamin D supplementation in individuals with a first demyelinating event (FDE), findings from the PrevANZ clinical trial's sub-study revealed dose-dependent effects on levels of genes in immune cells. Higher doses (5000 IU and 10,000 IU) altered the levels of gene related to the immune response and anti-inflammatory profiles. This suggests that vitamin D supplementation might impact immune function, although the clinical trial's primary goals were not met.

Unfortunately, challenges including recruitment issues due to various factors led to the closure of a study focusing on high-dose vitamin D therapy's effects on immune cell gene levels in people living with MS. This decision followed the negative primary outcome of the PrevANZ study and the modest outcomes of post-vitamin D supplementation gene level changes in immune cell subsets of MS participants.

The study on pregnancy and MS found that when women stopped taking medications like natalizumab or fingolimod, the risk of having a relapse during and after childbirth increased. They discovered that for women with a higher risk of having these relapses, using natalizumab before falling pregnant, continuing it until about 34 weeks into the pregnancy, then starting it again soon after giving birth, helped lower the chances of these relapses. However, strategies involving disease modifying therapies (DMTs) need careful consideration due to potential complications. These findings hold significance for pre-pregnancy counselling and planning.


Yeh WZ, Widyastuti PA, Van der Walt A, Stankovich J, Havrdova E, Horakova D, et al. Natalizumab, Fingolimod, and Dimethyl Fumarate Use and Pregnancy-Related Relapse and Disability in Women With Multiple Sclerosis. Neurology. 2021 Jun 15;96(24):e2989–3002.

Yeh WZ, Gresle M, Jokubaitis V, Stankovich J, van der Walt A, Butzkueven H. Immunoregulatory effects and therapeutic potential of vitamin D in multiple sclerosis. Br J Pharmacol. 2020 Sep;177(18):4113-4133. doi: 10.1111/bph.15201. Epub 2020 Aug 5. PMID: 32668009; PMCID: PMC7443468.

Updated: 31 March 2023

Updated: 21 January, 2020

Stages of the research process

Fundamental laboratory

Laboratory research that investigates scientific theories behind the possible causes, disease progression, ways to diagnose and better treat MS.

Lab to clinic timeline: 10+ years

Research that builds on fundamental scientific research to develop new therapies, medical procedures or diagnostics and advances it closer to the clinic.

Lab to clinic timeline: 5+ years
Clinical Studies
and Clinical Trials

Clinical research is the culmination of fundamental and translational research turning those research discoveries into treatments and interventions for people with MS.

Lab to clinic timeline: 1-5 years


  • Dr Wei Yeh

Grant Awarded

  • Postgraduate Scholarship

Total Funding

  • $42,560


  • 2 years

Read More

Newsletter subscription

  • Enter your details

How vitamin D affects the immune system in MS