Skip to main content

Vitamin D’s positive effect on sclerosis

Vitamin D’s positive effect on sclerosisThere is a link between vitamin D deficiency and sclerosis. However, only few studies show whether vitamin D supplements can stop further progression of the disease. A new placebo-controlled study of rats with advanced sclerosis has looked closer at the connection. The study, which is published in Nutrients, shows that vitamin D supplementation counteracts oxidative stress, chronic inflammation, and other processes that are involved in the neurological damage seen with this disease. It is important that vitamin D supplementation aims at optimizing blood levels of the nutrient, which requires higher doses than officially recommended. It also requires enough magnesium to help activate vitamin D and support the nervous system.

Multiple sclerosis (MS) is a chronic autoimmune disease in the central nervous system (brain and spinal cord) that typically affects younger adults. The condition is characterized by oxidative stress and inflammation that attacks and destroys the myelin sheath, an insulating lipid layer that forms around the nerves. This causes nerve impulses to malfunction and can also affect other parts of the central nervous system, which can result in tiredness, sensory disturbances, and symptoms in different parts of the body. MS is also characterized by attacks that are neurological symptoms or recurrence of previous symptoms that last at least 24 hours and are not caused by fever or infection.
Sclerosis is more common among women than among men. Smoking, obesity, and Epstein-Barr virus (EBV or mononucleosis) can increase the risk. The same goes for lack of vitamin D that is important for the immune defense and for most types of brain cells. It is a known fact that sclerosis is more common at northern latitudes, where we can only synthesize vitamin D during the summer period when the sun sits sufficiently high in the sky.

Vitamin D has a positive effect on several disease parameters

The researchers behind the new study used rats that had been exposed to inflammation and destruction of the myelin sheath surrounding the neurons, which is seen in severe sclerosis. They studied whether supplementation with vitamin D could reduce oxidative stress, inflammation, and different pathological processes in the central nervous system. They used dark Agouti rats and split the rats into two groups. One group was fed a standard rat diet plus vitamin D supplementation (10 micrograms every week), while the other group was only given their standard rat diet. The scientists assessed the rats’ brains by measuring different immunological and chemical markers related to:

  • Nerve cells – the most important type of cells in the central nervous system
  • Demyelination – damage to the myelin sheath of the nerve cells
  • Activation of microglia – a type of immune cells in the central nervous system that play a vital role in local inflammation and neurological degeneration
  • Apoptosis – or programmed self-destruction of cells
  • Neurofilament light chain - a marker of damage and degeneration, primarily of nerve fibers in the deep brain structures and spinal cord
  • Reactive astrocytes that are glial cells in the central nervous system
  • Oxidative stress - a condition where harmful free radicals outnumber the protective antioxidants
  • Total antioxidant capacity (TAC)

Vitamin D levels in the blood of the rats were also measured. The scientists observed significant differences between the rats that got vitamin D supplements and those that were only given a standard diet. These differences were reflected in all the different markers and the pathological tissue changes. The vitamin D-supplemented rats had less myelin loss and less microglial activation, suggesting that they had less inflammation and autoimmune reactions. The rats that got vitamin D also had less oxidative stress, and fewer of their nerve cells carried out apoptosis, which is a sign of healthier nerve cells. This study showed, altogether, that vitamin D has a positive effect on different pathological changes that are seen in sclerosis.

Supplements, optimal doses, and interactions with magnesium

In Denmark, the official recommendations for vitamin D are 5-20 micrograms daily. Certain vulnerable groups are advised to take 10-20 micrograms daily all year round. Still, none of these doses are sufficient for optimizing blood levels of vitamin D. The recommended daily intake of vitamin D for patients with sclerosis is typically in the range of 25-100 micrograms. The European Food Safety Authority (EFSA) has set a safe upper intake level of 100 micrograms/day. This is an amount most fair-skinned individuals dressed in summer clothing are able to synthesize on a sunny day during the summer.
Nonetheless, studies where participants have been given high doses of vitamin D have shown conflicting results, which is most likely because so many people lack magnesium. This mineral is needed to activate the type of vitamin D that we get from sunlight or from supplements. So, in other words, don’t expect your vitamin D supplement to work properly if you are not getting enough magnesium. Make sure to focus on blood levels of vitamin D, which should normally lie in the range of 75-160 nmol. People with sclerosis should aim for the highest blood levels.


Michaela Tanja Haindl et al. Vitamin D – An Effective Antioxidant I
in an Animal Model of Progressive Sclerosis. Nutrients 2023

Prince Sebastian et al. Association between Time Spent Outdoors and Risk of Multiple Sclerosis. Neurology December 8, 2021

University of California – San Fransisco. Sunshine may shield children, young adults from MS. ScienceDaily December 8, 2021

Walter Royal Update on Vitamin D. Multiple Sclerosis Centers of Excellence. U.S. Department of Veterans Affairs.

Anne Marie Uwitonze, Mohammed S Razzaque. Role of Magnesium in Vitamin D Activation and Function. The Journal of the American Osteopath Association. 2018

  • Created on .