Friday, April 2, 2010

Low Vitamin D: Cause or Result of Disease?

Don Matesz at Primal Wisdom put up a post a few days ago that I think is worth reading. It follows an e-mail discussion between us concerning a paper on magnesium restriction in rats (executive summary: moderate Mg restriction reduces the hormone form of vitamin D by half and promotes osteoporosis). In his post, Don cites several papers showing that vitamin D metabolism is influenced by more than just vitamin D intake from the diet and synthesis in the skin.

Celiac disease patients have low 25(OH)D3, the circulating storage form of vitamin D, which spontaneously corrects on a gluten-free diet. There are numerous suggestions in the medical literature that overweight and sickness cause low vitamin D, potentially confounding the interpretation of studies that find lower levels of illness among people with low vitamin D levels.

Don't get me wrong, I still think vitamin D is important in preventing disease. But it does lead me to question the idea that we should force down huge doses of supplemental vitamin D to get our 25(OH)D3 up to 60, 70 or even 80 ng/mL. When the dosage of supplemental D goes beyond what a tan Caucasian could conceivably make on a day at the beach (4,000 IU?), that's when I start becoming skeptical. Check out Don's post for more.


Unknown said...

Hi Stephan - Am I hammered or did you put up a post within the last few days about water quality, algae, etc.? I didn't get a chance to read it and would very much like to, but I no longer see it on your blog.

Chris Kresser said...

Hmmmm. Interesting. Do you think this implies that Vitamin D supplementation in these conditions with low D levels would only only offer a mild improvement, and that the real improvement wouldn't come until the cause of the deficiency (i.e. gluten consumption in those who are intolerant, losing weight in those overweight, etc.) is addressed?

signupsammy, the post you mentioned was an April Fool's.

Unknown said...
This comment has been removed by the author.
John said...

Perhaps most micronutrient levels are determined by "metabolic health," in that hyperglycemia (or hyperinsulinemia) "causes" deficiencies. This is certain for Mg, as is noted in a previous post of yours. I believe it also true for vitamin C (glucose competition)--now vitamin D too...

RachaelHD said...

I can't say, as I corrected the celiac and the magnesium and D all together, but I do know that I had pneumonia or sinus infections and serious flu every year of my life until I started the supplements and stopped the gluten. I have been off gluten for several years, and it's taken ever increasing amounts to get my D up to 40. So perhaps the spontaneous correction only happens if you correct the celiac early enough? I am aiming for 25OHD of 60, so I am upping yet again, to 5000 IU a day. No flu or pneumonia this year.

Miki said...

The optimal level of 25(OH)D should have been easy to determine. Just tell me what is the level of a typical Hadza or a Kitavan or a !kung. Only problem I am unable to find any reference. I vaguely remember seeing a number of 40 ng/ml somewhere but it may have been for monkeys.

David L said...

There was a rather persuasive demonstration of the efficacy of Vitamin D in diseases prevention in a California prison in the recent past. There were several wings of the prison, but the prisoners in one wing had been given Vitamin D supplements as part of some study. The vitamin-receiving population managed to avoid the brunt of an infectious epidemic that swept unabated through the other prisoner populations.

Miki said...

Vieth tables 50 ng/ml for "modern adults with abundant skin surface to sun exposure" (link), Is this fair or dark skin? Northern or southern sun? Who knows. Apes seems to have a higher level.

Miki said...

Here is the link in a more primitive manner

Jonathan Passey said...

According to the calculator and research done by the Norwegian Institute for Air Research, In Los Angeles California at noonday in July, on sand, a tan Caucasian can make 1000iu of Vitamin D3 in 4 minutes. That's right... 4 Minutes. And that is if they have their shirt ON.

Now I'm not sure if our bodies are physiologically capable of keeping that rate up for a whole day at the beach, but 4000iu was definitely an under-estimate.

I read about the Norwegian study here:

and the calculator is here:

They may or may not be solid sources but seem to agree with other studies I have read.

I live in Utah and take 5000iu of vitamin D between October and April and try to get sun each day in the summer. I have noticed fewer symptoms from colds and flus for my family since we have started supplementing through the winter.

PS. I was referred to your blog by Mike Robertson's blog. Thanks for the content.


brainpower said...

The body can easily make 10.000 I.U and more on a sunny day. BUT: if it gets to high there is an inbuilt mechansim, by which the body then breaks down the Vitamin D. But only if it comes from the sun. That, however does not work if you supplement. So oversupplementing may not be a good idea but supplementing surely is.

Anonymous said...

Hi Stephan,
totally off-topic, but whatever:
Have you read this already?

Do you think this is a superior way to prepare brown rice compared to the method you once posted?

TedHutchinson said...

First much as I love the calculator Jonathan Passey linked to we have to appreciate there is significant discord among the
UV scientists about the data on which that calculator is based.

We have to use our common sense and understand this is a heat driven process and if skin is too cold (wind chill) Vitamin D synthesis may not occur whatever the calculator says may be theoretically possible.

In practice While conversion occurred throughout the year at latitudes of 34◦N and below, no
production of vitamin D3 was found in the winter months of November to February at 42◦N (Boston) or October to March at 52◦N (Edmonton), even if the exposure time was extended to 3hr

If you enjoy laying stark naked in the snow that's fine but don't kid yourself your body is making any Vitamin D3 while you freeze.

David Moss said...

I'll second Jonathan, I was under the impression that we could produce more than 20,000 IU in around 15 minutes (the vitamin d council suggests 10,000 from 20-30 minutes exposure). I remember seeing the Hawaii studies that found that even very sun exposed people had levels between 12-70, but how many of these people were eating lots of grain one wonders?

Why can't we just let our bodies decide the optimal vitamin D levels? The impression I got from the vitamin D council was that we don't really start storing vitamin D in tissue until 40-50ng/ml. On the assumption that we would naturally (and optimally) store some vitamin D, we would therefore want at least these levels. I don't know whether vitamin D stored in muscle is actively doing anything useful or is simply being stored, but if the former then we'd want higher levels (until we have vitamin D in tissue) and if the latter then we should assume that we don't need more than 50 or so, since the body is just storing 'excess.'

As to the salivary stones that Don talks about, couldn't we simply make sense of this in terms of vitamin K deficiency rather than vitamin D toxicity (analogous to vitamin A toxicity really being vitamin D deficiency)? Chris Masterjohn, in his vitamin D safety article, notes that K protects from soft tissue calfication. If K is necessary for calcium to actually end up where it's supposed to be (rather than in the arteries or forming stones) then it would make sense that high levels of vitamin D (and hence higher calcium) would produce these effects in the absence of vitamin K).

Robert Andrew Brown said...

Thanks Stephan.

Could the celiac situation be a chicken and egg scenario where either removing wheat or improving gut integrity with vitamin D and so nutrient absortion would have resolved the vitamin D issue.

Celiac disease compromises gut integrity and so digestion including of vitamin D and minerals.

Immune responses I suspect increase Vit D usage.

Vitamin D improves gut integrity.

I agree that Vit D supplementation is not a precise art, and need will depend on sun exposure, sun cream usage, washing habits, conversion efficiency, gut absorption rates, skin tone, previous sun exposure, stored vitamin D, and likely genetics eg blonds and red heads.

Jake said...

"Low Vitamin D: Cause or Result of Disease?"

You used to be able to ask that question but not anymore.

Discoveries in the last two years have proved the biochemistry behind Vitamin D's disease prevention process.

Matt said...

Here is an interesting opposing view to the growing vitamin D supplementation movement. I've been supplementing to get my blood level up to the levels recommended by the Vitamin D Council, but this article has me questioning my decision. I am very curious to see how the study that is just beginning, turns out. Have you seen anything from this bacteriality group?

Relevant points: There are two active forms of D: 25 and 1.25. 1.25 is more biologically active, and tends to be high in immunosuppressed individuals.

The Vitamin D Council is presenting the science as if we are in the end game, but as we know with lipid research, it's easy to get caught up in associative studies and assume they're accurate as RCT's would be. Haven't had any RCT's yet on Vitamin D.

Mavis said...

I went back and forth with another reader of yours about a related issue a few posts ago. I think -

1) Our bodies might deal with dietary or supplementary vitamin D differently from the amount our bodies make from the sun.

2) The balance of related vitamins and minerals (K vitamins, magnesium, and A) probably affects how vitamin D acts.

3) Vitamin D may affect different parts of the immune system differently, possibly at different times in our lives. (This is the part I was discussing with the other reader - about the possibility that dietary or supplementary vitamin D might induce allergies in susceptible children.)

4) Different dietary patterns (such as consuming wheat or dairy or not) could affect vitamin D synthesis and/or metabolism.

I've been supplementing my kids with vitamin D since they were four months old, and myself as well. There is no way to determine cause and effect, but one daughter now has a life-threatening nut allergy and a serious egg allergy. I now seem to be newly allergic to nuts as well (going to get tested) - wonder if it has to do with my supplementing vitamin D in the past year. Fortunately, the sun is out now, an we can ease up on the supplements.

Here is an article I just found supporting the connection between vitamin D (from sun exposure, here) and anaphylaxis.

I also saw another a while ago, will try to find it again.

gunther gatherer said...

Thanks for this, Stephan. I was dosing with 10k IU per day for a 2 years while eating strictly paleo. Then I started eating quite high fat, a la Peter and Kwasniewski, and wound up in the hospital with 3 kidney stones, 2 in the ureter and 1 still in the kidney duct.

Of course, they could have been there all along (developed while I ate the SAD) and just decided to become symptomatic when they shrunk down to a size where they could pass down the ureter, but there's no way to tell. Anyway, I passed all the stones and CT scan now says I'm stone-free.

I agree that supplementation may not be necessary for those strictly grain-free. The incident has scared me enough to lower my dosage to 4k IU per day. The chicken-and-the-egg argument remains. Perhaps its all as simple as simply eating paleo and not micro-managing the rest...

Matt Stone said...


I've asked a lot of people who have tried the Marshall Protocol and they didn't have anything positive to say about it. What the bacteriality site does offer, however, is a glimpse into the complexity of vitamin D metabolism. It is not just an issue of quantity of ingestion or sun exposure.

But our bodies, designed for equatorial living, certainly require far more sunlight than we give them. No doubt about that.

Mavis said...

Matt Stone -

I generally agree with you about sun exposure nearer the equator, but keep in mind that if white people had been at the equator this whole time, they would not be white! So, to get a sense of what vitamin D requirements might be, you need to look at the vitamin D synthesis of a dark-skinned person living near the equator. Maybe that's obvious.

White folk lost their pigment synthesize and store D while the sun shines, so to speak. They may overcompensate during the summer because they risk deficiency during the winter. Perhaps dark skin doesn't just protect against UV damage at the equator, but too much year-round D synthesis. Just a thought.

By the way, UV exposure can significantly reduce folic acid status, enough that women using tanning beds in the early stages of pregnancy risk folic-acid-deficiency induced birth defects. (So don't do that.)

Alison Boden said...

Hi Stephan. Where did you get your data on 4,000 IU made by a caucasian in a day? The numbers that I've seen have been inconsistent but all much higher than that, say, 10-15k per 30 minutes of strong sunlight. Thoughts?

Carl said...

My understanding is that you only make Vitamin D from the UV-B rays of the Sun and it's also age related. Younger skin makes more D than older skin. Lighter skin makes more D than darker skin. An old method to determine if the UV-B light is getting through the atmosphere is to look at your shadow. If the length of your shadow is shorter than your height then you are getting UV-B exposure.

TedHutchinson said...

An old method to determine if the UV-B light is getting through the atmosphere is to look at your shadow.I'm afraid that only shows the POTENTIAL of UVB to reach ground level.
In practice in Urban areas (traffic pollution) less UVB reaches ground level compared with the same time of day at the same latitude in the country.
To further complicate the issue total UV radiation in towns is higher because Vitamin D degrading UVA is reflected from hard surfaces while in the country plants absorb it.
So we find TOWN women gardeners get more UV exposure but make less vitamin d and the reverse for Rural women gardeners.

Nigel Kinbrum said...

Matt said...
Haven't had any RCT's yet on Vitamin D.
I think you'll find that there have.

DogwoodTree05 said...

Interesting fact about folic acid, Helen. I, too, wonder about the actual sun exposure and vitamin D storage needs of very light-skinned people. I also wonder about overexposure. Is any accumulated sun exposure that does not cause burning safe?

Michael said...


I appreciate this more nuanced view of vit. D.

We shouldn't be advocating that everyone and their mother needs to start supplementing with 10k IU's a day.

Your points about how this is a complex and not fully understood issue further convince me that we should be following a 'precautionary principle' when it comes to d3 supplementation. It is a good thing sure, but no need to super-dose.

Personally, I take no more than 4k IU a day.

DogwoodTree05 said...

One more question:

Some very light-skinned people do not really tan and only develop reddened skin with freckles. What does this tell us about healthy sun exposure?

JBG said...

Here is an interesting opposing view to the growing vitamin D supplementation movement...

I read through most of this, as well as the two talks it references. Along with a great deal of FUD, the actual points seem to be:

(1) systemic inflammation at some level is *good* for you

(2) years/decades of vitamin D supplementation may expose us to chronic occult bacterial disease

with (1) being a protection against (2).

I'm not persuaded, but it does seem that there is some actual research being carried out, and that's good.

Nigel, that's a VERY long list, and they are not *all* RCTs. Wanna sort out the shorter list for us?

Alan said...

This post on Vit D is very timely for me. I recently recieved the results of a Vit D test through Grassroots Health and it is 50% higher than the last test. It is at a level that I think is to high. Why is this? I started thinking about it and realized it could be several things. I changed the manufacturer of the Vit D supplemnt I was taking, I slightly increased the dosage, I have minimized grain consumption and the grains I do consume I try to prepare properly and reduce the Phytic acid content. I also think pushing your level above 60ng/ml may not be prudent. I plan on reducing my supplement dosage to get my level back in that range.
I recommend that people get their Vit D levels tested at least twice a year because their are too many factors that effect Vit D levels

Gabriella Kadar said...

Let's not toss out the baby with the bathwater here.

Vitamin D3 is a fat soluble.
In order for the body to absorb it, bile salts need to be in the environment. (Same as with Vitamin K2 and A.) Fatty food (and I don't know how much fat is required here) will stimulate the emptying of the bile from the gall bladder. The bile salts thus released help to get vitamin D3 to pass through the small intestine walls.

People taking a supplement must be aware of what sort of food is in the stomach when they take the supplement.

There doesn't seem to be much in the way of defining whether consumption of a fatty meal along with the vitamin D3 supplement increases blood levels.

It seems a logical observation that people with damaged intestinal linings won't absorb Vitamin D3 regardless of type of food ingested. But these people won't be absorbing much in the way of minerals either due to inflamed gut lining.

There are people who have had their Vitamin D serum status evaluated after having taken supplementation for a period of months. There are those whose levels are in the desirable range and then there are people who have been taking 5000 iu for months and nothing changes.

Patients need to be informed that vitamin D3 must be taken with fats. (....mmmm loverly roasted chicken skin...)

If a person has problems digesting foods containing gluten then it would only make sense to stop trying to turn the undigestible into a digestible. But bread appears to be addictive even if it does cause bloating, gas and gas pain.

Mavis said...

Since I mentioned food allergy in my comment, thought I'd pass this along in case anyone is interested.

This is an article, and there are several others on PubMed, showing an extremely promising treatment using a Chinese medicininal formulathat looks like it could cure anaphylactic allergic reactions to food. Yes, cure. I wonder if it works epigenetically. It sounds legit to me. This article also mentions a promising treatment for asthma.

If Chinese medicine can be this powerful regarding allergy, it makes me wonder if the famous/infamous China Study took into account the possible effects of Chinese herbal remedies. There's a lot of focus on macronutrients and certain vitamins in my favorite health blogs, but I do wonder if more factors need to be taken into account when we compare cultures' diets and health outcomes. Other major factors, besides herbs and traditional medicines, could include indoor and outdoor air pollution and chronic stress (as Stephan's post "The Paleolithic Mind" suggested).

I think Don Matesz at Primal Wisdom has made this argument at least in terms of diet - don't expect the same outcomes as, say, the Kitavans, unless you eat everything they eat, including the herbs. There's probably no one magic bullet to health - just as these potent Chinese herbal formulas cannot be reduced to one herb - they work synergistically.

TedHutchinson said...

Circulating 25-Hydroxyvitamin D Levels in Fully Breastfed Infants on Oral Vitamin D Supplementation Full text online.
This shows 6400iu/daily required at lat 32N to raise mothers 25(OH)D to around 60ng/ml to provide optimum Vitamin D3 in breast milk.

I'd be interested to hear why people think 60ng/ml = 150nmol/l is not the primitive natural status our DNA evolved to function best with.

On the homepage of The vitamin D council website is an important section on
Vitamin D co factors that I think many people have either overlooked or ignored.

I would also like readers to look at the
Figures 1 and 2 in this paper showing the amount of Vitamin D3 STORED in tissue in relation to Circulating 25(OH)D. It is just the storage figures I want you to consider, not the argument or discussion in the paper that is now somewhat dated.

Given Vitamin D controls T cell antigen receptor signaling and activation of human T cells I suspect those maintaining 25(OH)D levels below the level at which reserves of D3 begin to accumulate may regret their decision.

Ellen said...

"Patients need to be informed that vitamin D3 must be taken with fats."

That's why it's accompanied with an oil when you buy it in a capsule or liquid form. If you look in the ingredients, there is usually olive oil or some other kind of fat provided as the "carrier". I've never seen Vitamin D3 alone as a supplement. It always has another fat with it.

TedHutchinson said...

Taking vitamin D with the largest meal improves absorption and results in higher serum levels of 25-hydroxyvitamin D.
Biotech Pharmacal offer D3 in a fine white powder in a capsule. The shells of the capsule can be pulled apart and the contents added to a meal. It's UVA light that degrades D3 so you can add it to the fat content when baking (cookies) or freeze it(ice cream) if you want to fortify foods at home. Generally Biotech stuff is cheaper if you search online rather than direct from manufacturer.
However I think Medium chain triglycerides MCToil is likely to be most efficiently absorbed, metabolized and have the longest storage life.

TedHutchinson said...
This comment has been removed by the author.
Tukki said...

We need to balance the information obtained from studies that are done in the typical Western controlled science way with a holistic approach.

Ten or so years ago, everybody I knew was eating oatbran out the wazoo because it lowered cholesterol. Then fish oil and omega 3 fatty acids took over, and now we're finding they are adding omega 3s to cookies.

Now it's Vit. D and I bet we'll start to see reports in the press about horrible cases of Vit. D overdose.

Can you imagine the French, say, changing how they make goose liver pate in order to increase the Vit. D or omega 3 fatty acid content?

One of the appeals of holistic health and nutrition for me is that it takes the focus off these isolated elements and puts it on aspects of life like the entirety of someone's diet; the satisfaction of one's work and social connections, and how much natural movement one gets in one's day.

And of course, you don't nearly read as much of the question "what is it about our lives that makes so Vit. D deficient, and how can we change how we live to make it better?"

Instead of just popping yet another pill.


Stephan Guyenet said...

Hi Chris,

Maybe. I don't know for sure. What I do know is that a recent high-dose placebo-controlled D3 supplementation trial in overweight people showed no effect on body weight, markers of inflammation, insulin sensitivity, or markers of CVD after one year.

Hi John,

That could well be.

Hi Rachael,

I take 4,000 IU on most days in winter here in Seattle. I rarely get sick either, although it's hard to say for sure if it's the D.

Hi Miki,

I know what you mean. I wish I could find that info.

Hi Jonathan,

My 4,000 IU comment was a very rough guess. What you have to keep in mind is that there's negative feedback on D3 production in the skin-- once you get a certain amount of UVB, the D3 you made starts to be degraded. If we really made 1,000 IU per 4 minutes all day, people who spend a lot of time in the sun like lifeguards would all have vitamin D levels of 300 ng/mL or more, but they don't.


That post is based on a paper that I forwarded to the author of that blog. Germination only breaks down a fraction of the phytic acid, and I'm not aware of any cultures that traditionally ate germinated brown rice. If you go to her next post, she describes the soaking/fermentation process I posted about (which I didn't invent) as a superior way to break down phytic acid.

Chris Kresser said...


Could you provide a link to the study you mentioned? I'd love to read it.


Stephan Guyenet said...

Hi Robert,

Could be. I think you're probably right that immune activation increases D needs.

Hi Jake,

I agree there's a mechanistic basis for believing that D is important in disease prevention. But it really hasn't been shown in trials, except for a few hints here and there. You should never make assumptions about the health effects of something based on mechanism.

Hi Matt,

I'd avoid the "bacteriality" site and other Marshall-associated sites as a source of information. They do have some good points, but they're so buried in misinformation that it's hard to tell what's correct and what's science abuse.

Hi Helen,

I don't find that study showing an association between EpiPen use and latitude in Australia convincing evidence of a role of D in allergy. That being said, oral dosing D3 in excessive amounts could have unforeseeen consequences. Many nutrients have a U-shaped relationship with disease-- there's an optimal amount at which disease risk is minimized, but more or less than that is not healthy. How much D were you giving your kids and taking yourself?

Hi gunther,

Wow! Did you ever get your 25(OH)D3 level checked to see what you serum level was when you had the stones?

Hi Alison,

My 4,000 IU figure was a very rough guess. Keep in mind that a tan person produces much less D than someone who's not tan. Most of the studies showing large D3 production with short UVB exposure were done in non-tan Caucasians. If we really made that much D3 continuously, even modest sun exposure over time would cause hypercalcemia, but it doesn't. There's negative feedback on the system to prevent that.

Hi Michael,

I agree. The precautionary principle is very important to keep in mind!

Stephan Guyenet said...

Hi Ted,

Thanks for that link to the D council's page on D cofactors.

TedHutchinson said...

@ Chris Kresser said...
Reduction of dietary magnesium by only 50% in the rat disrupts bone and mineral metabolism

I can't access the full text but the abstract is worth reading.

Mavis said...

Hi Stephan,

I initially gave them 400IU/day (recommended by mainstream sources, like our pediatrician) from 4 months on, as part of a multivitamin. I discontinued the multivitamin at some point. Did not do D supplements last summer because we got a lot of sun. In fall, started giving 800IU/day.

Me: 2,500IU per day in winter in their first year, started taking 4000-5000IU per day last fall.

I'm finding other studies finding associations between vitamin D status and increased allergy, atopy, and anaphylaxis - will pass along the links once I read them if they seem worth sharing.

I also found a study that found folic acid (folate) supplementation in late pregnancy may also play a role in the development of asthma:

Geesh! It's all too much, with all the hullabaloo about supplementing folic acid in early pregnancy. You really have to be on your toes and stay on top of that folic acid.

Then there's another study suggesting that folate may help treat asthma. I guess it just wants to be involved.

Interesting that D status is increased from sun exposure while folate is decreased. It's tempting to try to find a grand plan in this pattern.

Mavis said...
This comment has been removed by the author.
Chris Kresser said...


The confusion you describe is one reason I'm not a huge fan of supplementation in general, and why I prefer instead to eat a nutrient-dense diet and let my body do the rest.

We know just enough to be dangerous at this point. But I can't help thinking sometimes that pharmacology and nutritional supplementation are very crude (and often counterproductive) attempts to manipulate a vastly complex and sophisticated system that we have only a fragmented understanding of.

Mavis said...


Just to clarify...

I doubt that the amounts of D that may be setting more allergic disease in motion are excessive in terms of what we need for overall health.

My theory is that D activates part of the immune system that we originally evolved to fight parasites (and maybe some bacteria). Sans parasites, our immune system gets out of balance and starts overreacting to other substances.

Parasite therapy has been used successfully to treat MS, another illness potentially related to vitamin D - in this case, inadequate D.

I don't know the lingo off the top of my head yet, but from my skimming it seems we secrete something in response to parasites that helps keep our autoimmune and allergic responses in check.

I think this is what may be at work with the Chinese remedy - it is traditionally used to treat parasites. So it may mimic that substance in the immune system that is lacking in allergic individual individuals that modulates IgE and cytokine production.

Mavis said...


I heartily agree.

Chris Kresser said...


Whipworm therapy is also used to treat Crohn's disease, which is associated with low D levels.

Stephan Guyenet said...

Hi Chris,

Here are the papers:

No effect of supplementation with cholecalciferol on cytokines and markers of inflammation in overweight and obese subjects

No improvement in cardiovascular risk factors in overweight and obese subjects after supplementation with vitamin D for 1 year

Hi Helen,

I think your theory is speculative but plausible. I'm open to the idea that a lack of intestinal parasites is part of the problem-- it's a part of the hygiene hypothesis that usually gets overlooked. It's somewhat counterintuitive, but the fact is that we evolved with intestinal worms so we may be dependent on them in certain ways. It may be that low-level infection with certain parasites is beneficial, but of course in certain situations they're clearly harmful.

Mavis said...

Still not ready to eat worms.

Though I've long thought the paleo and traditional foods communities were giving bugs a short shrift in their diets.

Unknown said...

Yes, a balance of co-factors are needed if a person is taking more than about 4000 IU per day. Lots of details on vitamin D at VitaminDwiki dot com. You can also participate in discussions read vitamin D news via RSS from 10 sources, and read some of the 900 files.

Lou said...


I'm not sure if I want to rely on Science Daily website because they posted an article over vitamin D and African Americans saying that they do not need vitamin D but the study is flawed. How do I know all the stuff from that website is not flawed? That's why I'm skeptical of that place.

what said...

Getting a real fringe vibe from this stuff. Not sure if I'm reading quackery or what.

Lou said...


Do you always make sure they used gold standard testing? You already know that some studies can have various numbers if not used gold standards.

I personally believe that extra vitamin D supplement during the winter because of lifestyle we have now leading to low Vitamin D level. I can tell you that for the first time in forever that I went through without sinus infection while I ate terrible. I do take magnesium supplenment. Dr Cannell does say to take co-factors but I don't believe that most people even consumed enough of them. I am vastly surprised that they even have paleo clinal trial tests that showed excellent numbers. I did countless hours of researching from all over the internet as I've gotten tired of those books from big box stores as I knew it isn't what it claimed to be. When Paleo book came out, I initially thought "another BS diet book" and then you mentioned those clinical trial studies involving paleo diets. I'm amazed how close I was to that kind of diet on my own. That was maybe 6,7 years ago. Like they say, fat melts like butter on the hot pan. Hunger isn't that extreme. I'm glad I came across that trial. I'd never know for sure why American Heart Association, American Cancer Society, and others refused to acknowledge any of latest findings. Perhaps their financial ties to those companies profiting off sick peoples? We'll never find out...

Nigel Kinbrum said...

JBG said...
Nigel, that's a VERY long list, and they are not *all* RCTs. Wanna sort out the shorter list for us? I know. I wrote at the beginning of my post that I was including Editorials (as they are interesting) and some are human trials showing the inadequacy of 400iu/day. If there were 100 hours in a day, I'd have put a short summary after each link. Sadly, there aren't!

Mavis said...

Hi Lou,

Science Daily just aggregates press releases of various studies that come out. Some are good studies, some are not. I doubt Science Daily makes any judgment about their quality before they churn them out.

I certainly don't rely on them!

Usually, the actual studies can be found elsewhere, but I just check SD out on a regular basis as infotainment, for points of departure for thinking about things, but hardly for proof.

Even stuff found on PubMed can't be taken as proof! Again, some are good studies, some are not.

JBG said...

Here's a sketchy case report relevant to several things in these comments.

I have an acquaintance, a very thin guy, who some time back went from what was almost certainly severe vitamin D deficiency (years of obsessive sun-avoidance) to what was almost certainly massive vitamin D excess (10ks of IU/day).

In fairly short order, he went crazy.

After stopping the D and recovering his marbles, he had a large residue of health problems. He reported recovery after obtaining and inoculating himself with two forms of intestinal parasites.

(It was after I reported the vitamin D part of this story to Dr. Cannell that he added the section about vitamin D cofactors to his homepage.)

Mavis said...


If you're still checking this string, like I was saying....

Latest post from Cooling Inflammation:

"Parasitic worms reverse allergies and autoimmune diseases using oligosaccharides to mimic self and silence immune over-responsiveness."

Maybe I am ready to eat some worms.

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WilliamS said...

I wrote to the Vitamin D Council to ask if they had a reaction to the two uninspiring Vitamin D clinical trials Stephan cited. For what it's worth, here is their response (not from Dr. Cannell, though):

Since both papers studied vitamin D's effects in obese subjects, it is very possible they would have had better results had they used higher doses of vitamin D. Around 10,000 IU per day would have probably been more appropriate.

Studies show an inverse relation between percentage of body fat and serum 25(OH)D levels, indicating a higher BMI will trap vitamin D in adipose tissue and not release it as needed. Because of this, those who are obese will require higher dosages of vitamin D to achieve vitamin D repletion and thus, the beneficial health effects:

I'm not convinced this fully answers those trials, since in at least one of them, according to the abstract, average serum levels above 50 were achieved in the higher dose intervention group.

Stephan Guyenet said...

Hi Google,

I agree with you, I think the subjects had plenty of vitamin D, it just didn't change any of the variables they measured. This is a big blow to Cannell's hypothesis that vitamin D deficiency is the central cause of the diseases of civilization. I have to admit, I'm a bit disappointed myself that it had so little effect.

The subjects started out around 23 ng/mL 25(OH)D3, and ended up around 55 ng/mL in the high-dose group. If 55 ng/mL isn't high enough to see an effect of vitamin D supplementation, then there probably is nothing to see. That doesn't mean it isn't doing anything, it just means it didn't affect the variables the investigators measured. I'll be interested to see trials where they look at actual disease outcomes.

Chris Kresser said...

I'd be particularly interested in seeing studies on outcomes in autoimmune disease, since that has been a huge focus of vitamin D research.

Is the low vitamin D status seen in autoimmune disease correlation or causation? And is vitamin D supplementation actually therapeutic in these conditions?

There are plenty of studies like this one, which identifies an association between autoimmune disease (Crohn's, in this case) and vitamin D deficiency, and even proposes a mechanism for how D deficiency contributes to the disease. But that still doesn't prove that supplementing with D improves outcomes in Crohn's disease.

I did find one in vitro study which examined the effects of 1,25 D (calcitriol) on Th1/Th2 cytokines in patients with Crohn's disease (CD) and Ulcerative colitis (UC). It was a small study, but the results suggests that calcitriol has a selective immunomodulatory effect in CD and UC patients:

The effects of calcitriol incubation were: 1) reduced IFN-gamma (p=0.024) and increased IL-10 (p=0.06) production in UC patients; 2) reduced TNF-alpha production in CD (p=0.032); 3) no significant effects in HC. Calcitriol increased, albeit not significantly, IL-10 production in UC compared to CD patients (p=0.09). These results suggest an important modulatory role of vitamin D in the Th1/Th2 immune response. The observation that the effect of this modulation was different in CD compared to UC patients provides an interesting area of research into the pathogenesis and treatment of these inflammatory conditions.

So at least here we have some evidence (albeit in vitro) that D supplementation could alter specific markers of inflammatory bowel disease. That's another step in the right direction, but still no research on outcomes that I'm aware of.

TedHutchinson said...

@ Stephan
The high group were only taking 40,000iu/week =5714iu/and the trial was only for 1 yr.

Startling Findings About Vitamin D Levels in Life Extension® Members By William Faloon This article shows what happens when people just take 5000iu/daily over 3~9 months. These folks, not as far north as Norway only average 42ng/ml

I can't get the full text of the paper No effect of supplementation with cholecalciferol on cytokines and markers of inflammation in overweight and obese subjects but personally I doubt the obese participants in this trial maintained a sufficiently high 25(OH)D level for long enough for it to have had a profound effect on their inflammatory status.

It would be better if in future trials they corrected vitamin D deficiency first and the comparison started AFTER the participants in the "effective" strength group had attained and maintained an even 25(OH)D level above 50ng/ml for 3 months.

I think it's naive to think immediately you cross a specific threshold for 25(OH)D all inflammation ceases instantly.

My experience has been, the longer I stay around 60ng/ml the less pain I experience.

helper said...

Disease is the cause of low Vitamin D levels - see papers published in 2008 and 2009: