The push to prevent skin cancer may have come with unintended consequences—impaired brain function because of a deficiency of vitamin D. The “sunshine vitamin” is synthesized in our skin when we are exposed to direct sunlight, but sunblock impedes this process. And although vitamin D is well known for promoting bone health and regulating vital calcium levels—hence its addition to milk—it does more than that. Scientists have now linked this fat-soluble nutrient’s hormonelike activity to a number of functions throughout the body, including the workings of the brain.
“We know there are receptors for vitamin D throughout the central nervous system and in the hippocampus,” said Robert J. Przybelski, a doctor and research scientist at the University of Wisconsin School of Medicine and Public Health. “We also know vitamin D activates and deactivates enzymes in the brain and the cerebrospinal fluid that are involved in neurotransmitter synthesis and nerve growth.” In addition, animal and laboratory studies suggest vitamin D protects neurons and reduces inflammation.
Two new European studies looking at vitamin D and cognitive function have taken us one step further. The first study, led by neuroscientist David Llewellyn of the University of Cambridge, assessed vitamin D levels in more than 1,700 men and women from England, aged 65 or older. Subjects were divided into four groups based on vitamin D blood levels: severely deficient, deficient, insufficient (borderline) and optimum, then tested for cognitive function.
The scientists found that the lower the subjects’ vitamin D levels, the more negatively impacted was their performance on a battery of mental tests. Compared with people with optimum vitamin D levels, those in the lowest quartile were more than twice as likely to be cognitively impaired.
A second study, led by scientists at the University of Manchester in England and published online this past May, looked at vitamin D levels and cognitive performance in more than 3,100 men aged 40 to 79 in eight different countries across Europe. The data show that those people with lower vitamin D levels exhibited slower information-processing speed. This correlation was particularly strong among men older than 60 years.
“The fact that this relationship was established in a large-scale, clinical human study is very important,” Przybelski says, “but there’s still a lot we don’t know.”
Although we now know that low levels of vitamin D are associated with cognitive impairment, we do not know if high or optimum levels will lessen cognitive losses. It is also unclear if giving vitamin D to those who lack it will help them regain some of these high-level functions.
Because cognitive impairment is often a precursor for dementia and Alzheimer’s disease, vitamin D is a hot topic among Alzheimer’s scientists, who are racing to answer these questions. Przybelski, for example, is planning a study of vitamin D supplements in healthy, normal elderly adults living in an assisted-living community to see if it will affect their incidence of Alzheimer’s in the long term.
So how much is enough vitamin D? Experts say 1,000 to 2,000 IU daily—about the amount your body will synthesize from 15 to 30 minutes of sun exposure two to three times a week—is the ideal range for almost all healthy adults. Keep in mind, however, that skin color, where you live and how much skin you have exposed all affect how much vitamin D you can produce.
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23 Comments
Add CommentNow I wonder if D can make it through glass..
Reply | Report Abuse | Link to thisIf this was true - wouldn't people that lived near the equator "perform better" than those living near poles, over the course of history?
Reply | Report Abuse | Link to thisThere's also the issue of resources, Candide.
Reply | Report Abuse | Link to thisVitamin D isnt a frequency of light, its a vitamin that is produce in the skin upon contact with Ultra Violet B radiation. If the glass your behind blocks UVB, then your skin will not be able to produce Vitamin D.
Reply | Report Abuse | Link to thisNot necessarily. The complexity of the challenges (social / occupational etc) within a person's environment also play a role in the development of a person's cognitive capabilities.
Reply | Report Abuse | Link to thisWhat is the 2nd & 3rd best way to get your Vitamin D...besides the sun...and taking the actual vitamin. Any food source?
Reply | Report Abuse | Link to thisAside from the Sun...what other ways to get the needed Vitamin D ? Any food sources...or..is it just a vitamin alternative?
Reply | Report Abuse | Link to thisfoods with D here http://www.algaecal.com/vitamin-d/vitamin-d-sources.html
Reply | Report Abuse | Link to thisNo, because as people migrated away from the equator they evolved lighter skin to increase Vitamin D synthesis. Inuit people in Alaska, however, have maintained a dark skin color because their diet is so Vitamin D-rich that synthesizing it themselves is not an issue. In fact, there is now a much higher instance of rickets (a Vit D deficiency disorder) in people of African descent living in Canada, as their skin color evolved for an environment of much higher sunlight.
Reply | Report Abuse | Link to thisVitamin D alone is not enaugh for people to perform better. There is a complex of vitamins and proteins and other substances needed for the brain. Minerals in the soils, the time needed for the skin to be exposed to the sun so that it can synthesize Vitamin D, dependent on skin color and melanin pigment in the skin.
Reply | Report Abuse | Link to thisIs there a connection with another recent article in S.A.on glial cells (astrocytes) and their functioning explained with a "calcium wave" and their impact on the thought process? Can we assume that the deficient vitamin D levels negatively affecting the calcium levels might be pointing to astrocytes actually influencing the cognitive process? The lower the vitamin D levels--the lower the calcium levels--the greater the level of cognitive impairment--thus perhaps validating the assumption that thinking may have as much to do with the workings of glial cells as neurons? Has this been studied especially in the implied association with the onset of Alzheimers?
Reply | Report Abuse | Link to thisRegarding the Inuits of Alaska and other native Alaskians, I've had contact with healthcare practitioners from Alaska stating they are finding severe vitamin D deficiency on blood tests. Many Alaskians have abandoned the traditional diet that is high in vitamin D (Salmon, other seafood) for a more fastfood diet.
Reply | Report Abuse | Link to thisIt's just not true that white people maximize vitamin D production, if a white spends the day at the beach he won't synthesize any more 'D' than the darkest African. The synthesis shuts off once 10,000 IU is made in all humans.
Reply | Report Abuse | Link to this<a href="Was Roman Britain multiracial? ">Mad dogs and .... </a>"It looks like natural selection has aimed for an optimal vitamin D level substantially lower than the recommended minimum of 75-150 nmol/L. This in turn implies some kind of disadvantage above the optimal level. "
We need a retrospective cohort study that looks at D3 levels and student assessment levels. Note that OECD PISA (Program for International Student Assessment) shows that students in Finland and northern countries have the highest math/science/reading test scores where D3 status should be low. PISA test performance by race (In America) seems to correlate with prevalence of D3 deficiency.
Reply | Report Abuse | Link to thisWe need a retrospective cohort study that looks at D3 levels and student assessment levels. Note that OECD PISA (Program for International Student Assessment) shows that students in Finland and northern countries have the highest math/science/reading test scores where D3 status should be low. PISA test performance by race (In America) seems to correlate with prevalence of D3 deficiency
Reply | Report Abuse | Link to thisWe need to stop promoting milk as a "source" of vitamin D and, for that matter, calcium. The protein level in milk is so high that consumption of milk and dairy products puts people in negative calcium balance. Consuming milk causes protein induced hypercalciurea (high + calcium+ in the urine). Get D3 and calcium from the same place cows get it: sunshine and green grass.
Reply | Report Abuse | Link to thisI recieve vitamin B12 injections while going through chemo and radiation treatments for my brain cancer, my neurologist asked that it be tested, he never said anything about testing my vitamin D levels?
Reply | Report Abuse | Link to thisIf white people were getting more Vit D because of their skin color. Wouldn't Inuits people skin color turn white also, just because the Vit D is so good for you?
Reply | Report Abuse | Link to thisVit D is a secosteroid and surpresses the immune system. Makes you feel good just like any other steroid when used on sick people. Yes it might temporarly improove cognitive function. In the long run its not good.
It has only been in the last several years that physicians have become more aware of the multitude of benefits of adequate D levels. Ask your physician to check we haven't all caught up with the news.
Reply | Report Abuse | Link to thisI take a vitamin D supplement. There is no way that I can get what my body needs from my diet unfortunately. I also work in an office all day 5-6 days a week and don't get to see the sunlight that often so that does not help. I take Vitamin D3 1000 from Jarrow Formulas and I get it at www.VitaminLab.Com because they have the best prices on Jarrow products and they are my favorite brand.
Reply | Report Abuse | Link to thisI take a vitamin D supplement. There is no way that I can get what my body needs from my diet unfortunately. I also work in an office all day 5-6 days a week and don't get to see the sunlight that often so that does not help. I take Vitamin D3 1000 from Jarrow Formulas and I get it at www.VitaminLab.Net because they have the best prices on Jarrow products and they are my favorite brand.
Reply | Report Abuse | Link to thisYou can get enough vitamin D from fortified milk and other dairy products to get your minimum RDA, which is all it supposedly takes to prevent rickets. Rickets is the primary concern of mainstream Medical Doctors in relationship to vitamin D. Most could care less about you having "optimal health" and most arent into preventative medicine other than losing weight.
Reply | Report Abuse | Link to thisTo answer your question, no it is basically impossible to get higher levels of vitamin D from food sources.
Other than eating large amounts of oily fish from cold Northern waters practically everyday, really the only way to get higher levels of vitamin D is the way nature intended you to get it...sunshine exposure. Other than that, its vitamin D supplements. You can also fall back on the old school, time tested treatment of taking a tablespoon of cod l iver oil everyday. This is what most people did back in the old days...meaning up until the sixties sometime. My Dad grew up taking a tablespoon full of cod liver oil everyday.
Now the recomendation is a teaspoonful a day, probably because of legal CYA fears of getting too much vitamin A. Personally, I think doctors in the old days had a better attitude, at least back then most of them wanted to help you. Now its just push the latest drug and listen to the drug companies.
If you are already low on formal blood labwork, its unlikely taking an OTC vitamin D will restore your vitamin D levels. And if it does, it will probably take forever. What you need to do is go to a doctor who is educated about vitamin D, have the formal bloodwork, see if you are actually low. If you are, they will prescribe you the prescription stuff, the 50,000 IU a week pill. Combined with regular exposure to sunlight WITHOUT sunscreeen will probably bring your vitamin D levels up to acceptable levels reasonably fast.
Reply | Report Abuse | Link to thisYou need to keep in mind that ALL doctors these days are scared of getting sued and are NOT going to recommend to you ANYTHING that could in the slightest harm you. So you will find very few doctors who might diagnosed you with vitamin D deeficiency who will also tell you, "yeah, you need to go sunbathe." But its probably what they are thinking you should do.
But they will prescribe you the prescription strength vitamin D pills, thats safe for them from a legal perspectve. Encouraging suntanning is not...if you by chance get a skin cancer your lawyer can come back and say, "well the doctor told my client to suntan and they got skin cancer."
I dont listen to anybody but myself on this issue. I take the supplements plus lay out in the sun. If I get skin cancer, thats my business and I did it to myself. But one thing is for sure, you will NOT have optimal health with low vitamin D levels!