Can getting more sun help protect against dementia?

Alzheimer’s disease is a form of dementia, and its cause is likely to be ‘multifactorial’ and even vary considerably between individuals. However, on thing that appears to be true is that a key driving process in the condition is inflammation (which, by the way, seems to be true for ‘chronic’ conditions). One potential anti-inflammatory agent is vitamin D, and I was interested to read about a recent study which found significant links between low vitamin D levels and risk of developing Alzheimer’s disease and dementia in general.

In short, what this study found is that in those deemed to be low in vitamin D (levels < 50 nmol/l), risk of Alzheimer’s and dementia were raised by 69 and 53 per cent respectively. In those deemed ‘severely deficient’ (levels 25 - < 50 nmol/l) risks were elevated by 122 and 125 per cent respectively. Analysis of the data revealed that there is some sort of threshold below which risk of dementia and Alzheimer’s increases markedly, and that threshold is around 50 nmol/l. This research is ‘epidemiological’ in nature, and cannot be used therefore to infer that vitamin D helps prevent dementia. It could be, for instance, that those prone to dementia are less likely to get outside in the sun, and are prone to lower vitamin D levels as a result. However, in this study, people were followed over a period of time (an average of about 5½ years), at the start of which no-one had dementia. In this context, the increasing risk of dementia over time seen in those low in vitamin D points a bit in the direction that the link might be causal (i.e. that vitamin D deficiency might actually provoke dementia). Interestingly, vitamin D has been found to counter specific mechanisms that have been implicated in the development of Alzheimer’s disease [2].

I think it’s too soon to draw and conclusions about the role of sunlight and vitamin D in dementia. However, I’d say this is ‘one to watch’. If it should turn out that optimising vitamin D levels has benefits for the ageing brain, I don’t think I’ll be too surprised.


1. Littlejohns TJ, et al. Vitamin D and the risk of dementia and Alzheimer disease. Neurology. 2014 Aug 6 [Epub ahead of print]

2. Dursun E, et al. A new mechanism for amyloid-β induction of iNOS: vitamin D-VDR pathway disruption. J Alzheimers Dis. 2013;36(3):459-74

14 Responses to Can getting more sun help protect against dementia?

  1. Kathy 8 August 2014 at 4:42 pm #

    Dr. Briffa, I would love it if you would look into the relationship of vitamin D to calcium levels. Calcium is essential to so many of the body’s functions, yet if a person takes too much vitamin D, they can suffer joint pain (for example). We have too many warnings about low vitamin D levels, and none about going too high!

    • Mary S 8 August 2014 at 10:45 pm # has in depth information on vitamin D. Vitamin D is best obtained from the sun (also see sections on safe sun exposure); however if taken as a supplement (D3 and not synthetic D2) then it should be taken with vitamin K2 and the other fat soluble vitamins to ensure that the calcium is absorbed by the bones and is not floating in your blood. The much feared vitamin D toxicity is excess calcium in the blood and not a type of a toxin.
      Some people that takes Calcium supplements also have excess Calcium in their blood – supplementation with Magnesium (and fat soluble vitamins A,D,E,K) will ensure that the Calcium is absorbed by the bones. People on very low fat or fat free diets will have difficulty absorbing fat soluble vitamins.

  2. Vanessa 8 August 2014 at 5:00 pm #

    Interesting thought. If it is also the case that getting enough vitamin D is helpful for treating or stabilising dementia then it’s such a shame that the elderly people in the dementia home where my partner’s mother was staying hardly go outside and when they do they are smothered in sunblock, thus negating any positive effect of direct sunlight and vitamin D synthesis. I spoke to one of the carers there about this very issue and she said she had been told always to put strong sun block on the residents, even if they weren’t out in very strong sunlight. Oh well….

  3. Angele 8 August 2014 at 5:11 pm #

    I will not be surprised as well. I believe the SUN is a natural vitamin and may be entered not only through the skin cells but also through the iris of the eyes. This is why I never wear sunglasses nor sun screens and spend no more than 30 minutes in the sun each day. Of course if I am going to be on the beach for longer periods I use sun screens and hats for protection.

    Our society has demonized the sun in order to make tons of money and everyone buys the koolaide. In my neighborhood I see all ages including babies in strollers in hats and sunglasses. Corporate America is alive and well while its people are dying of diseases.

    • Frederica Huxley 8 August 2014 at 7:37 pm #

      Kathy, it is my understanding that problems arise re calcium/vitamin D only if they are taken in isolation. Add in vitamin K and magnesium and an alkaline diet to vitamin D3, and the calcium will stay in the bone matrix, not in the bloodstream. As to overdosing on Vitamin D, it is best to have an 25(OH)D test every six months to monitor your levels.

  4. John Walker 8 August 2014 at 9:13 pm #


    You might also have heard that Rickets is making a reappearance, and seems to coincide with the advent of sun creams and advice to keep out of the glorious sunshine, thus depleting supplies of Vitamin D. I wear sunglasses now, but that’s because at my age, the glare does affect my eyes. Having spent a lot of my youth in sunny climes, working stripped to the waist, I am surprised that I don’t have many wrinkles. Is this evidence that some more ‘conventional wisdom’ is wrong? I also wonder if it isn’t the sunlight that causes the cancers, but the fact that individuals are not eating the right foods. With the right foods, the body has the proper ‘anti-oxidants’ in the right amounts to fight these conditions. I can’t prove it, but it’s what I believe. Diet is key, and eating grains, starch and sugar isn’t the way to go!

    • Angele 14 August 2014 at 7:41 pm #

      TOTALLY agree with YOU. Food is medicine but one has to be their own doctor and not outsource their health to others. I believe we are each individuals and need to educate our self and realize no matter what letters come after a so-called expert in the filed is still always only their opinion and never a fact!!! Better to form our own opinions rather than buy into conventional wisdom driven by MONEY.

  5. Soul 8 August 2014 at 9:19 pm #

    I remember providing my elderly grandmother with vitamin D3. At that point her mind was often lost. Having a conversation with her was difficult. She was irritable and fussy most days. I recall that after supplementing it didn’t take long for her personality to change. Her demeanor brightened up. She became more engaging. It was surprising, as I remembered reading that it often takes months before a change is seen after supplementing, but that wasn’t the case with grandma. It seems to take a few weeks to see a nice, brighter mood our of her.

    Sadly the change didn’t last. She stopped taking the vitamin D3 at some point. I never could get an answer from her why that was. And her personally returned back to how it was before.

  6. Mark Johnson 9 August 2014 at 12:02 am #

    At noon-ish in the UK on a sunny, summers day, a fair skinned individual exposing full body will make about 10,000 – 25,000IU Vitamin D after about 30 – 60 minutes in the sunshine. A dark skinned individual will make less and an older person less as well.

    As a general rule, 5000-10000IU supplementation per day for most people is about right, year round. The dangers of Vitamin D overdosing just doesn’t happen in real life at those types of doses and supplementing at those levels will get most people into the 125 – 175nmol/L range – which is where studies are now suggesting optimum levels should be.

    Re the calcium issue, just remember to eat foods high in Vitamin K2 or take a K2 supplement.

  7. Dawn 9 August 2014 at 1:03 am #

    I have already got 2 chronic diseases, hard to balance and this makes me housebound much of the time. I am afraid of dementia. I would love to get out in the sun. I would love to be able to take vitamin d without problems too but it give me pains in bones, pains in teeth in particular. Sore red eyes and sometimes on a moderately high dose panic attacks. Doctor do you have any idea why this might be? I know I need it. Our country has been giving some sun this summer but I just haven’t been well enough to get out. I don’t have a garden and if I want to get out it is a case of a taxi to somewhere and I am just not well enough for that most days.

    • madge hirsch 18 August 2014 at 2:02 pm #

      Are you supplementing with magnesium as well? Vit d seems to use up magnesium. I too had panic attacks but when taking magnesium these went away. You can take tablets, eat lots og green leafy veg and nuts and put Epsom salts in the bath.

  8. Babs 9 August 2014 at 4:39 am #

    Does that mean people who live in hotter climates than the UK are less likely to get dementia?

  9. Liz Glen 9 August 2014 at 6:55 am #

    Those living further north do not appear to suffer more from Alzheimer’s even though the amount of sunshine is considerably less. This may be due to the amount of oily fish the consume.

  10. M. Cawdery 9 August 2014 at 12:18 pm #

    All my literature research on Vit D3 and Alzheimer’s (AD) is basically in agreement with the proposition that a healthy blood level of Vit D is associated with a lower incidence of AD. However, there are other factors involved such as diabetes; indeed there are researchers that suggest that AD in some cases could be described as “diabetes Type 3″. In turn this links in with the following study: Stephanie Seneff, Glyn Wainwright, and Luca Mascitelli, “Nutrition and Alzheimer’s Disease: The Detrimental Role of a High Carbohydrate Diet,” European Journal of Internal Medicine 22 (2011) 134-140; doi:10.1016/j.ejim.2010.12.01

    Then of course the role of statins in causing diabetes, and the acknowledged adverse neurological damage (polyneuropathy and memory loss) must be considered along with the possibility of prion infection.

    AD/PD 2009 – Are We Experiencing an Alzheimer’s Epidemic?
    Incidence Has Soared Enormously
    March 25, 2009 (Prague, Czech Republic) — The world may be experiencing an epidemic of Alzheimer’s disease (AD) that is not entirely attributable to an aging population, new research suggests.

    The fact is that AD is now an epidemic; in the 1960s the incidence of AD in 85+ year-olds was 2% (1 in 50). In the present time the incidence in 85+ year-olds is expected to be in the order of 50% (1 in 2). This is clearly not a function of age (same age group) and is suggestive of one or more causal factors.

    What they are is a matter for research but will this be done with an open mind? I doubt it!

    As an example the study (Dement Geriatr Cogn Disord 2009;28:75–80
    DOI: 10.1159/000231980 Can be downloaded in full. Midlife Serum Cholesterol and Increased Risk of Alzheimer’s and Vascular Dementia Three Decades Later.. Alina Solomon et al.)

    This study showed that high cholesterol 2-3 decades earlier was associated with an increased incidence of AD. However, there was no intervening data AND NO TREATMENT DATA (medical records without treatment data??? something hidden?)
    However, by changing the row titles in Tables 2-4 from cholesterol levels to the official guideline treatment means that the numbers and statistics remain the same but the alternative interpretation is very different – cholesterol lowering treatment (probably stains from the late 1980s) increased the incidence of AD by ~58%.

    No wonder this research is very, very rarely cited. Furthermore, this study could easily be repeated by US health insurance companies and NHS Trusts. But it won’t be. The results could well end the pharmaceutical industry as we know it.

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