Vitamin D (VitD)
is a fat soluble vitamin that is mostly known for good bone health. So how does
VitD affect patients with Multiple Sclerosis (MS)?
Multiple Sclerosis is an autoimmune disease that affects the nervous system. In MS, the body’s immune system attacks the myelin (protective insulation) of nerves and causes inflammation and scarring. Evidently this can cause nerve deterioration and nerve cells in the brain and spinal cord cannot communicate with each other and muscles as fast as they normally would.
In simple terms once myelin is destroyed, electrical signals cannot travel along the nerve as quickly as they should. This damage causes muscle weakness, blurred vision, poor coordination, fatigue, numbness and paralysis. Symptoms may be temporary or permanent are different for every person with MS.
VitD regulates immune responses in MS and it has been found that VitD levels are lower in MS patients compared to healthy people.
There are different types of MS, but this study looked at people with relapsing remitting Multiple Sclerosis (RRMS).
Previous studies studied the role of interleukins secreted from immune cells in MS. Interleukin 17 (IL-17) is a an important cytokine that has proinflammatory effects and it is secreted by T cells in patients with MS. Cytokines are important proteins that are responsible for cell signaling to pass information onto other cells.
In this study, 94 Iranian patients with RRMS were randomized in a double blind, placebo controlled experiment. The experimental group received 50,000 IU of vitamin D3 every five days for 12 weeks and the control group received the placebo (sugar pill) at the same time. All patients received interferon β (IFβ) treatment as well. Blood samples were taken before and after the study to observe complete blood count, serum levels of Calcium and serum levels of IL-17. This was done to see how VitD affects IL-17 in RRMS patients.
IL-17 was an important factor focused on in this study because other studies showed that VitD reduced the number of IL-17 secreting cells in MS patients. Since IL-17 is a proinflammatory cytokine, decreasing the number of IL-17 secretions would be good for MS patients since inflammation of myelin destroys nerves.
Results showed a statistically significant difference in the levels of IL-17 between the experimental and control group. Serum levels of IL-17 in the experimental group went from 56.75(baseline) to 58.93, and from 30.31(baseline) to 46.13 in the control group. IL-17 levels increased by 60% and decreased by 40% in the experimental group and increased by 67% and decreased by 33% in the control group. Serum calcium levels remained in the normal range, with no statistical significance in this experiment.
So what does that mean? This means that patients who received high doses of VitD has less increases of IL-17 than the control group who didn’t consume VitD. By having lower IL-17 levels, this might mean that higher doses of VitD may be more beneficial to patients with RRMS than lower doses.
Are high doses of VitD safe for MS patients? Yes, having sufficient levels of VitD is important and this study showed that patients consuming higher doses of VitD had an increase in VitD that were in the normal limits. The levels of calcium and D3 were safe for RRMS patients in this study.
These findings can be controversial because each person is different and has a different base level of VitD and IL-17, therefore needed doses of VitD may vary from patient to patient.
Although this study showed that there was a significant difference in IL-17 levels in MS patients after consuming large doses of VitD for a short period of time, further studies should be done to see how VitD affects IL-17 and if it can possibly prevent myelin degradation.
Personally, I’m curious to know what other impacts VitD can have on MS since I take care of several patients with this disease.
Works Cited:
Toghianifar, N., Ashtari, F., Zarkesh-Esfahani, S. H., & Mansourian, M. (2015). “Effect of high dose vitamin D intake on interleukin-17 levels in multiple sclerosis: a randomized, double-blind, placebo-controlled clinical trial.” Journal of Neuroimmunology, 285, 125-128. doi:10.1016/j.jneuroim.2015.05.022
Interesting article, Jessica. Whenever I thought of Vitamin D before, I was thinking more of calcitriol and related processes. However, the information in this blog was very different from what I am used to associating Vitamin D with. I am wondering what pathway Vitamin D is involved in to decrease IL-17 levels. I was also very curious about MS and have been much more informed after reading your blog.
ReplyDeleteI first learned about Multiple Sclerosis (MS) when I took Introduction to Neurobiology with Dr. Yurco and we talked about the difficulties of diagnosing it. It's interesting that Vitamin D plays role in MS. I wonder if the individuals diagnosed with MS have low levels of Vitamin D because they are not consuming enough milk as the study found that Vit. D levels are lower in MS patients compared to healthy people.Just like Jennifer I would have not thought Vitamin D intake affects interleukin levels. This is very interesting blog and I would really like to learn more about the effct of Vitamin D on MS patients.
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