Sunlight’s ability to protect against multiple sclerosis may go beyond vitamin D

Multiple sclerosis (MS) is a neurological disorder. At its root, is degeneration of the fatty sheaths that surround the nerve fibres in the brain and spinal column. The degeneration of these sheaths (known as myelin sheaths) disrupt neurological function, and can manifest in any number of ways including physical disability and impaired brain function. It’s been noted that populations further from the equator have increased risk of MS compared to those closer to it. Perhaps not surprisingly, these have led some to investigate the role of vitamin D and sunlight in relative protection from MS.

It is generally believed that MS is ‘autoimmune’ in nature – which means it’s caused by the body’s immune system reacting against its own tissues (in this case, the myelin sheaths). There has been quite a lot of evidence which suggests that vitamin D has the capacity to modulate the immune system in a way that can dampen any tendency to autoimmunity [1].

However, new evidence has come to light that at least some of sunlight’s apparent ability to protect against MS is not down to vitamin D at all.

The study in question used an ‘animal model’ of MS known as experimental autoimmune encephalomyelitis (EAE) [2]. In this study, laboratory animals with this condition were exposed to ultraviolet (UV) light. This led to dramatic reductions in the activity of the disease. However, the UV light only brought about a small and transient rise in vitamin D levels in the animals. The magnitude and duration of this rise would be insufficient to account for the considerable benefit conferred by the light.

The authors of this study conclude that “These results suggest that UVR [ultraviolet radiation] is likely suppressing disease independent of vitamin D production, and that vitamin D supplementation alone may not replace the ability of sunlight to reduce MS susceptibility.

Before we get too ahead of ourselves, let us bear in mind that this is an animal model of MS, and only one experiment. However, what it does do is open up the possibility that some, possibly many, of sunlight’s apparent wide spectrum of benefits for the body are not mediated through vitamin D, but by other not-well-understood mechanisms.

Personally, I’m going to continue supplementing with vitamin D. But I’m also going to do my damndest to get as much sunlight exposure as I can (without burning) too.


1. Raghuwanshi A, et al. Vitamin D and multiple sclerosis. J Cell Biochem 2008;105(2):338-343

2. Becklund B et al. UV radiation suppresses experimental autoimmune encephalomyelitis independent of vitamin D production. Proc Natl Acad Sci 22 Maarch 2010 [epub ahead of print]

11 Responses to Sunlight’s ability to protect against multiple sclerosis may go beyond vitamin D

  1. Dr. Tim Gerstmar 5 May 2010 at 9:52 pm #

    Dr. Briffa,
    Thanks for posting this. It seems like we’ve probably slipped once again into the reductionistic mindset of sunlight = vitamin D. So take Vitamin D and you’re all set. Like most things (foods, nutrients, herbs) we see that the rush to find THE active constituent usually results in disappointment.
    While, as you said, it’s important to not treat mice or rats as furry humans (we have quite a few differences) this is one more piece to help motivate MS patients (everyone really) to get out in the sun safely more often.

    Dr. Tim Gerstmar

  2. Robert Horner 6 May 2010 at 4:18 am #

    Dr. Briffa,

    Some folks out there still contend that as we age, most people will lost the ability to produce much vitamin D from sunlight, and from this they conclude that we should cover up as much as possible or reach for the sunscreen. I have always felt that whether you needed to supplement with oral vitamin D or made enough from the sun, that as much frequent exposure, as you said without burningm, was a good policy to subscribe to. This post would seem to indicate that those saying that if D production from sunlight isn’t sufficient that we should automatically cover up in some way is possibly missing the boat by a wide mark.

    Do you feel that in time more experts will start to recommend plenty of sun exposure without burning even in cases where oral D supplementation is necessary, or will it likely be a case of clinging to the suggestion to avoid the rays, especially when you need oral D supplementation anyway?

  3. Bill 6 May 2010 at 4:33 pm #

    I have been thinking along the same lines. I believe there are many other health benefits from full spectrum sunlight.

    Barry Groves wrote an interesting article.
    Full Spectrum Sunlight and Inner Health :

    I stopped wearing sunglasses 2 years ago, except when driving where glare is an issue.

  4. Peter Andrews 6 May 2010 at 9:45 pm #

    I have suspected for a while that there may be other benefits to sun exposure beyond vitamin D. For one thing, we know that vitamin D photodegrades into a variety of substances, many of which we do not know the purpose of.

    Evolution is parsimonious — if sunlight was useful in making one steroid hormone perhaps it creates other useful things as well.

  5. Debra 7 May 2010 at 8:12 pm #

    It’s a shame that westernized medicine has lost track of answers found in nature, things that are not harmful to the body but in fact are good for us and necessary. This blog is a breath of fresh air every time I come to it.

  6. Diana1 9 May 2010 at 11:21 am #

    The article recommended by Bill ( is very interesting. I have wondered for some time as to whether soft fruits and salads grown in polytunnels offer the full range of benefits that fruits and salads grown in the open air do. I do not know whether there is any research on this ” but as polytunnels enable crops to be extended in season and it is thus more profitable to use them it is not something that people would be rushing to research. And what particular properties do you decide to investigate?

  7. The other (non-dietician)Kate 10 May 2010 at 11:21 am #

    Thanks Dr Briffa for posting this information.
    Most people with MS, who have a thirst for information which may help them, (I’m one of them) have started supplementing their diets with Vitamin D3.
    I’d like, if you don’t mind too much, to write about the newest MS theory, which is causing people with MS, a great deal of anguish.
    Chronic Cerebral Spinal Venous Insuficiency (CCSVI).

    If this newest theory about MS and what it is, becomes more prominent in the medical journals, it may turn treatment of MS on its head.

    ‘Liberation’ is what the treatment is called right now. The use of angioplasty and stents to help open occluded jugular veins seems to be provoking a great deal of interest.
    It moves the treatment of MS, from not only neurologists, but now involves vascular specialists as well.

    The UK (as usual) will be lagging far behind the US and Canada. At this moment no hospital is testing Dr Paolo Zamboni’s theory. If you want to read more about this, I suggest the website as there is a great deal of information about Dr Zamboni’s research there.

    I’m lucky. I’m not severely disabled. I take beta-interferon, Low Dose Naltrexone and try to stick to a Paleolithic diet.
    MS is rather like Diabetes, in terms of diet as a treatment.

    On one side, you have the theories of Dr Roy Swank (very low fat, high starchy carbohydrate diet) which seems to work for some people.
    At the other end of the spectrum, there is a diet which resembles the Paleolithic diet. The most important idea being that the dieter should avoid gluten and dairy and legumes.

    Both these diets work well. Trying to work out which will work is very difficult. No MS expert will ever tell people to eat a specific diet as they are convinced that there is no link between controlling MS and diet.

    The MS Society is keeping quiet about CCSVI. They are advising the government (whoever that will be) to deny that CCSVI will help anyone.
    People are right now, travelling to Poland to be tested and then treated. So far, the statistics from a trial in Buffalo US, are looking like 65% of people with MS have occluded jugulars.
    The ‘Liberation Treatment’ won’t help everyone. It would appear that this, plus vitamin D3 and diet and LDN and one of the clinically trialled drugs, can stop MS progression in its tracks.

    Sorry for writing such a long post, but this is important to people with MS.
    Thanks again.
    Katrine Roberts
    ‘The other Kate’

  8. Ernestine 22 October 2011 at 12:25 am #

    Alas, if it is true that sunlight provides a range of autoimmune modulating benefits, those of us with systemic lupus face a powerful dilemma in that uv rays cause flares of the illness, with attendant rash, joint pain, and other symptoms. Doing without sun exposure is one of the hardest aspects of lupus for me, but so far there seems no way around it. I do take vitamin D3, which has helped me a great deal.

  9. VItamin d foods 17 December 2013 at 10:23 pm #

    Although a direct effect of UV can underly the benefit in this study, I think many other studies have show a direct effect of vitamin D in other autoimmune diseases. Ad direct effect of Vitamin D on TH17 cells (as well as other cells) has been demonstrated. These TH17 cells are a specific subset of the white blood cells, that are known to be involved in almost all autoimmune diseases.So the studies described are important, but bear in mind that there is mounting evidence for a direct effect of VItamin D!


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