This post was originally written three years ago, July 19, 2009. Since we have been discussing D3 and D2, I thought that would be a good idea to revisit my thoughts at that time.
Well it seems like almost since the start of understanding vitamin D in the 1930’s that vitamin D3, cholecalciferol, is equal to vitamin D2, ergocalciferol. This thought continues on today even by some of the best researchers on vitamin D.
Now before we dive right into this discussion let’s just say that vitamin D3 is better than D2 for humans because of the impact on genes and it is less toxic. In other words, take D3 and not D2 as D3 is better. If your doctor prescribes D2, ask him if it is okay for you to take an equal amount of D3 as it will be more effective to your health. Vitamin D3 is readily available even in 50,000 IU quantities (since this post was written, the FDA has approved 50,000 IU of D3 from Bio Tech Pharmacal to fill scripts). If your doctor says no, then get a second opinion or at least have him read from the journals listed below.
I would like to say thank you to the journals and to the authors who have made their papers open access to help in the understanding of treating chronic disease.
Consider this article that was written in 2008: “D2 as Effective as D3 in Maintaining Circulating 25(OH)D Levels” Holick et al, : J Clin Endocrinol Metab 2008 Mar;93(3):677-81. Epub 2007 Dec 18 Now this article was written in part by Dr. Michael Holick and I consider him to be one of the best researchers of vitamin D. After all he did get fired from his job after writing the book the “UV Advantage.” But the above paper really puzzles me and you have to read the abstract carefully to understand what Dr. Holick is saying.
First, he is talking about levels of serum 25(OH)D that are necessary to heal rickets. That is that 99% of all rickets is healed at 25(OH)D level of 20 ng/ml or less. So here is where the problem begins. Also read this statement carefully from the Conclusion: “A 1000 IU dose of vitamin D2 daily was as effective as 1000 IU vitamin D3 in maintaining serum 25-hydroxyvitamin D levels and did not negatively influence serum 25-hydroxyvitamin D3 levels. Therefore, vitamin D2 is equally as effective as vitamin D3 in maintaining 25-hydroxyvitamin D status.”
Note very carefully in this statement how 25(OH)D, 25(OH)D2, and 25(OH)D3 are used. This is the language of confusion that has always been used in vitamin D research where everything that even closely resembles a D compound is called vitamin D. The sum of 25-hydroxyvitamin D2 plus 25-hydroxyvitamin D equals the total value of 25-hydroxyvitamin D. In the future, you should be very careful at the higher serum levels above 50 ng/ml because most of the work with vitamin D is now being done with D3. When you go to the higher levels, then the above conclusion no longer holds.
At higher levels, the effect of serum 25(OH)D is better understood from this paper:
The Journal of Clinical Endocrinology & Metabolism Vol. 89, No. 11 5387-5391 Copyright © 2004 by The Endocrine Society, Vitamin D2 Is Much Less Effective than Vitamin D3 in Humans, Laura A. G. Armas, Bruce W. Hollis and Robert P. Heaney
Consider this statement from the abstract: “Vitamin D2 potency is less than one third that of vitamin D3. Physicians resorting to use of vitamin D2 should be aware of its markedly lower potency and shorter duration of action relative to vitamin D3.”
As you read the two papers you see that they are talking about two different ranges of 25(OH)D. The efficacy of disease prevention and treatment only begins’ at the higher ranges. And many researchers think that to get the best benefit, the 25(OH)D level should be above 60 ng/ml and that it should be 25(OH)D3. Now the normal of a sunny country according to a paper, Benefits and Requirements of Vitamin D for Optimal Health: A Review by Dr. William Grant of SUNARC, is a level of 25(OH)D3 of 54 ng/ml to 90 ng/ml. This sounds like a target for a normal range and is much more predictive of preventing disease than the range that the medical professions currently use of 20 to 100 ng/ml. It’s just that the minimum level needs to be raised.
I may have used the word efficacy above and should not have. Equal potentcy does not mean equal efficacy. That is that they treat disease at the same level of quality or with the same outcome. So even at the lower levels of potency where D2 and D3 are equal at raising 25(OH)D levels, I suspect that 25(OH)D3 is more efficacious in treating disease. Ah, the language of misdirection and the medical profession should be a blog on its own.
Equal potent does not mean equal efficacy!
Efficacy is what opponents to the population taking enough vitamin D to have an effect on disease are screaming about. “There is not enough research on the efficacy of vitamin D they scream,” but they have much thinner research on the various drugs that they are touting. “Heal the population but do not heal the portion that I have targeted for my drug because I have spent millions in research and we would not want something like sunshine to keep me from making a profit.” Boy, I believe I was a lot angrier three years ago than I am now. Of course this practice of confusing the population for profit goes on as shown by the conflicts of interest allowed by the Institute of Medicine’s Food and Nutrition Board in 2011.
Of course it is forgotten that the test on efficacy was run during the twentieth century when most of the population was taking two tablespoons full of cod liver oil per day or about 2600 IU of D3. Ever hear of anyone dying from vitamin D toxicity? The Vitamin D Council on toxicity. Neither have I. How about have you ever heard of anyone dying from liver failure where consumption of acetaminophen is the number one cause?
I am not bitter from the 25 years of chronic pain I suffer, just using this energy of healing to try to help the rest of you folks. Sorry if sometimes it sounds like whining but I will repeat from a previous blog that standing in Germany and watching the holocaust without taking action does not sit well with me and neither does watching people suffer and needlessly die from chronic disease.
And second so what do rats have to do with vitamin D2 and D3. Well it seems like rats just love vitamin D2 as it works better for them than does vitamin D3. Rats are nocturnal animals and get their vitamin D primarily from eating plants and fungi that have made D2 after being irradiated with sunshine. Isn’t it interesting that we have used rats extensively in testing for vitamin D when vitamin D2 is more efficacious in rats than vitamin D3 and this is the opposite for humans?
In the following paper, Dr. Vieth, a real hero in vitamin D research from the University of Toronto, shows how in other species that D3 is more effective by a factor of 10 at potency and that D2 is more effective for rats.
Here is the open access paper: The case against ergocalciferol (vitamin D2) as a vitamin supplement Lisa A Houghton and Reinhold Vieth, American Journal of Clinical Nutrition, Vol. 84, No. 4, 694-697, October 2006
So why and when did we start to use D2 and not D3. JY Moon and Dr. CJ Reich considered this very problem from a 1975 paper entitled “The Vitamin D Problem” . This is a most read and explains how the cases of toxicity did not start until we started to use D2 and how D2 can lead to more disease. Now this is in 1975 just prior to the time that I begin to start suffering pain and there was not one doctor good enough to ask about my serum vitamin D level – D2 or D3! Don’t go into the sun and if you do wear sunscreen as it will prevent skin cancer, but what about the disc disease in my spine that is very similar to rickets?
Where are the government agencies that are supposed to protect us from the misadventure of profiteers? Oh yeah, they are protecting the profits and the economy for Wall Street.
Go into the sun!!!!!!!!!!!!!!!!!!!! When you cannot, supplement with D3 only!!!!!!!!!!!!!! – Pandemic Survivor Well, it does not look like much has changed over the last three years in the clinical practice of treating vitamin D2 and D3 as equals! I suspect there will be a lot of papers become unless when the effects of 25(OH)D2 versus 25(OH)D3 are finally determined.