What they won’t tell you about Vitamin D

Vitamin D continues to be all the rage and, as a result of my blog, I have gotten some questions. One question that has come up is the role of Vitamin A in interfering with Vitamin D metabolism. One person went so far as to suggest that Vitamin A causes cancer because it defeats the cancer fighting properties of Vitamin D.

I will address that in a bit but based on the response to my last blog on D “Dr Dave Does ‘D’” there are a few more things that people want to know.

First question was, “How does vitamin D interfere with cancer formation?”

Answer: Vitamin D has a lot in common with fish oil. Both have anti-inflammatory properties that ultimately are helpful and both are nutrigenomic compounds meaning that they influence the transcription of genes.

While it is known that most vitamins are cofactors for reactions in the body and needed for these reactions, it is my hypothesis that all the major vitamins (including E, A, C, K, etc.) are actually involved in gene expression.

This is undoubtedly one of the roles of Vitamin D.

In numerous other writings I have stressed the preservational effects of Vitamin D on the all important “biologic time clocks”, the telomeres.

Longer telomeres also prevent cancer.

So we know of at least three ways that we can prevent cancer with Vitamin D either directly or indirectly: anti inflammatory properties, genetic transcription, alteration and telomere length preservation.

Vitamin D’s effects on two of these three pathways are best demonstrated by its role in infection. It’s probably no coincidence that winter (when sun exposure is down) leads to more infections. It’s not just that there are more infections around because most of these things--including influenza--are there year round at least in some numbers.

It is the immune status of the individual that makes the susceptibility.

But Vitamin D both enhances and decreases some genes associated with inflammation and infection response, creating a “perfect storm” of natural response.

The same for fish oil, although here is what happens on the internet: Some whiz kid who is not a doc or a scientist decides that fish oil is anti-inflammatory so it must be potentially dangerous in the influenza outbreak. For the very same reasons I mentioned with Vitamin D, fish oil, which contains no vitamin A and very little D by the way, enhances the body’s responses.

This is what happens when people do not dig deep enough into statements made, and it’s how rumors and urban legends get started.

Now onto Vitamin D and Vitamin A.

Both have immune function signals through the same pathways and indeed do have some competitive actions. Both have been shown to improve the response to infections independent of each other although the target populations differ.

There is one and only one study that suggests this may have consequences in something called adenomatous polyps of the colon.

Adenomatous polyps, if left untreated, can eventually turn into colon cancer but the rate of simple adenomas is the lowest of all of the adenomas, so it makes a difference what kind of adenoma (for instance villous adenomas transform to cancer in one quarter of cases). Lots of things figure into the transformation size, type and location but it is safe to say that complete eradication of adenomatous polyps would indeed get rid of almost all colon cancer, which is why I personally had a colonoscopy.

Through all this, please understand I am the last person on the planet who wants either of us, you or me, to have cancer of the colon!

But I do want you to see how “facts” are not always accurate and why.

No mention of the type of polyps was seen in this study.

Worse yet, the Vitamin A and Vitamin D intakes were based on a “food questionnaire”, not measured values. Any scientist will tell you questionnaire based studies are the most notoriously flawed of ANY kind of study and right there, any real accuracy has to be questioned in regards to the conclusions reached.

The authors of the study also used the exact phrases “weak association” for the benefits of Vitamin D and adenomas.

Here is a quote from the extract which is public domain:

“Total Vitamin D intake was weakly associated with reduced risk of distal colorectal adenoma. The combinations of high vitamin D and low retinol intake (RR = 0.55, 95% CI: 0.28, 1.10) further decreased risk of distal colorectal adenoma when compared with the opposite extreme. Higher total calcium and vitamin D intakes were associated with reduced risk, and the actions of vitamin D may be attenuated by high retinol intake.”

Please note the use of the words “extreme” and “may”, both of which are qualifiers.

OK, so now you have one study done by questionnaire that does not come out and say Vitamin A causes cancer but here is an example of what one of “my
people” wrote in:

“Basically, the site reported that Vitamin A conflicts with uptake of Vitamin D, causing untold higher incidence of cancer, which Vitamin D helps to prevent. Further, it said that cod liver oil, a traditional source of Vitamin A, should not be used any more.”

I do not know exactly who wrote this information or which web site it came from but I am familiar enough with internet marketing to know how it works. Also I do not really know if the people on this web site used the words “untold higher incidence of cancer” but if they did it is extremely hyperbolic and premature and is not something anyone who is a scientist would say.

If I had to guess, I smell the hand of a copywriter or team of same.

I could be wrong but I think not.

I will tell you this much: I write every word of what you read in my emails and my blogs and any other communication I have with you. That does not mean that people who use teams of writers are wrong or bad, I am simply telling you it's different and ultimately you must be the judge of what you hear and believe.

At any rate, no other study has ever said anything about Vitamin A and cancer and the cited study is so full of holes, I suspect that is one reason no one has tried to repeat it.

Simply put, this is my position: any assertion that Vitamin A increases cancer needs far more work to be proven to my satisfaction.

I do think Vitamin D is preventative.

In addition there are two other very important general conclusions I do agree with.

First, Vitamin D is under tested, under recognized and clearly an epidemic nutritional deficiency. It is absolutely important that we use 25 OH vitamin D levels to look at Vitamin D status and we can do a huge amount of good for the world by getting everyone’s 25 OH Vitamin D levels above 50. Mine was at 83 last time I checked and it’s certainly no lower now!

Second, I agree with the general recommendation that cod is an inferior way to get Omega 3’s. I have always said that and continue to maintain that stance. As I have also always said, I personally believe that fish oil is the way to get your Omega 3’s. It’s the most studied and it’s the way our ancestors got it and all the populations based studies and benefits of Omega 3’s have been studies using fish or fish oil, not any other source including those that show improvements in colon cancer rates!

The bottom line is most of us could use more Vitamin D!!!!

In defense of the myth of cod liver oil being healthy, however, I will say that back in the day (1930’s) cod did have much higher ratios of Vitamin D to Vitamin A than now and I think that ultimately will be where the true “healthy” approach lands.

Cod consumption, as the studies show, is also a great way to get arsenic and mercury poisoning!

J Toxicol Environ Health A. 2007 Nov;70(22):1897-911.
Heavy metals in Pacific cod (Gadus macrocephalus) from the Aleutians: location, age, size, and risk.

Burger J, Gochfeld M, Shukla T, Jeitner C, Burke S, Donio M, Shukla S, Snigaroff R, Snigaroff D, Stamm T, Volz C.

Division of Life Sciences, Environmental and Occupational Health Sciences Institute, Rutgers University, Piscataway, New Jersey 08854-8082, USA. burger@biology.rutgers.edu

If a subsistence fisher from one of the Aleut villages ate one meal of cod per week for As, or one meal per day for Hg, they would exceed the U.S. EPA reference dose for As and Hg.

Finally, I want to remind you that a very famous study showed that multi vitamins, which typically contain Vitamin E and C, 10,000IU of Vitamin A and 200 to 400 IU of D improved telomere length by 5%.

Here is an abstract quote: Compared with non-users, the relative telomere length of leukocyte DNA was on average 5.1% longer among daily multivitamin users (P for trend = 0.002).

Am J Clin Nutr. 2009 Jun;89(6):1857-63. Epub 2009 Mar 11.
Multivitamin use and telomere length in women.

Xu Q, Parks CG, DeRoo LA, Cawthon RM, Sandler DP, Chen H.
Epidemiology Branch, National Institute for Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA.


As a final reminder our Fitcamp Cancun is coming up and holistic icon, medical pioneer and marketing genius, Dr Joe Mercola, has the expert lecture on Vitamin D so you can come and ask him about this and other related topics yourself!!!