If you've been persuaded (certainly I've tried) that you need more vitamin D maybe (but probably not) you've wondered what form of vitamin D you should take. Well renowned vitamin D researcher Michael Holick, PhD, MD, basically has found that you can take vitamin D as D2 or D3 without worrying which is more potent.
Boston, MA— Researchers from Boston University School of Medicine (BUSM) have found that vitamin D2 is equally as effective as vitamin D3 in maintaining 25-hydroxyvitamin D status. The study appears online in the December 2007 issue of the Journal of Clinical Endocrinology & Metabolism.
Researchers studied healthy adults aged 18-84 who received either placebo, 1,000 International Units (IU) of vitamin D3, 1,000 IU of vitamin D2, or 500 IU of vitamin D2 plus 500 IU of vitamin D3 daily for three months at the end of winter to establish what effect it had on circulating levels of total 25 (OH)D as well as 25(OH)D2 and 25(OH)D3. Sixty percent of the adults were vitamin D deficient at the start of the study.
Adults who received the placebo capsule daily for three months demonstrated no significant change in their total 25(OH)D levels during the winter and early spring. Adults who ingested 1,000 vitamin D2/d gradually increased their total 25(OH)D levels during the first six weeks. Adults who ingested 1,000 IU of vitamin D3 had a baseline 25(OH)D that was statistically no different from the baselines of either the placebo group or the groups that took 1,000 IU of vitamin D2/d or 500 IU vitamin D2 plus 500 IU vitamin D3/d. The vitamin D3 group increased their serum 25(OH)D levels similar to that of the group that ingested vitamin D2.
The circulating levels of 25-hydroxyvitamin D increased to the same extent in the groups that received 1,000 IU daily as vitamin D2, vitamin D3, or a combination of 500 IU vitamin D2 and 500 IU vitamin D3. The 25-hydroxyvitamin D3 levels did not change in the group that received 1,000 IU vitamin D2 daily. One thousand IU of vitamin D2 or vitamin D3 did not raise 25-hydroxyvitamin D levels in vitamin D deficient subjects above 30 ng/ml.
Even if you haven't wondered about this particular burning vitamin D research question at least this serves as a reminder that vitamin D probably will reduce your odds of cancer, auto-immune disorders, infections, osteoporosis, and assorted other maladies.
By Randall Parker at 2008 January 02 10:02 PM Aging Diet Studies | TrackBackThe important finding is that 1000 units/day couldn't get the Vitamin D level above 30ng/ml. Fortunately, it is a low cost item in either D2 or D3 form. The desired level is 50-60 ng/ml.
D2 vs D3, oil-based cap vs powdered tablet, now this. ARGH! I'll be getting my Vit D (2 or 3, whichever) from the sun while bicycling and gardening, and from cod liver oil capsules during the few cold spells we have on the 29th latitude until they figure this stuff out.
FYI, I had my 25-hydroxy vitamin D level checked five months ago and it was 17, should be around 50.
I live in South Calif and bike/hike every weekend.
I took 2000 units of vitamin D per day for five months and just had my level rechecked. It had moved up from 17 to 27.
I'm now taking a once weekly 50,000 unit pill for 8 weeks, plus my usual 2000 units per day.
Bottom line, get tested to really know what your level is.
I've ordered a bottle of Nordic Naturals' "Arctic-D" cod liver oil. Should handle the Omega 3 and vitamin D issues at the same time. Sounds like I ought to hit the doc up for a blood test after I've been on it a little while, though.
I personally find that Sunlight vitamin D through the skin is very different than vitamin D run through the digestive tract. Born in Vienna, educated in Canada, however after my degree I moved to Hawaii because of the amount, and angle of sunlight. 20 years in Hawaii, hours in the Sun,did a film in Puerto Vallarta, and in doing so, I noticed my cells felt at home, check the globe, sure enough tropic of Cancer. 10 years in Vallarta, got restless now live in Cancun, again angle of sunlight. I go to my roof, sun naked for one and half hours daily, all one color now, and feeling good. I feel like the Son of the Sun, never a thought of skin cancer, no one can beleive my age, I just look and act half my age, for many it might not be possible for me the sun is better than vitamin D supplement, your skin absorbes information from the sun, you can't get that from a pill. I'm 58 years old, sunning the last 40 years no problems, so I will continue my relationship to the sun, permanent tan for me, don't be shy google my name Peter Knopfler. Thankyou.
Here is another medical study that reaches the opposite conclusion.
Vitamin D2 Is Much Less Effective than Vitamin D3 in Humans
LAURA A. G. ARMAS, BRUCE W. HOLLIS, AND ROBERT P. HEANEY
Creighton University (L.A.G.A., R.P.H.), Omaha, Nebraska 68131; and Medical University of South Carolina (B.W.H.), Charleston, South Carolina 29425
http://www.electricbeachtan.net/Vit_D2_vs_D3.pdf
The Journal of Clinical Endocrinology & Metabolism 89(11):5387–5391
Copyright © 2004 by The Endocrine Society
doi: 10.1210/jc.2004-0360
Moderate exposure to UV light (sunlight or in a tanning bed) on skin is the best source of vitamin D3.
A single tanning bed session can process 15,000IU of healthy natural vitamin D3.
Be careful not to overdose on cholcalciferol (vitamin D3), also known as rat poison.
It is better to get your vitamin D naturally from moderate exposure to UV light.
Some thoughts:
The sun may deliver other benefits beyond Vitamin D, but of course don't overdo it.
Cod liver oil not a good way to get Vitamin D because the Vitamin A component is much higher and toxicity is a real possibility with that.
Toxicity with Vitamin D almost unknown. Consider that 30-45 minutes in midday sun helps you produce 30,000 units without any ill effects.
According to their reference materials for doctors, that Arctic-D cod liver oil contains, per teaspoon,
1000-2000IU vitamin A
400IU vitamin D
5IU vitamin E
625mg DHA
410mg EPA
225mg other Omega 3s
600mg Oleic acid
So I'll be suplementing it with pure Vitamin D, rather than trying to take enough of the cod liver oil to get all my vitamin D.
Dear Mr. Parker,
This work advances the understanding of the pharmacokinetics of vitamin D2 and vitamin D3 metabolism; however it does not provide a basis for assuming that vitamin D2 has equivalency with vitamin D3 with respect to cancer or chronic disease prevention. The study interprets the increase in serum 25-hydroxyvitamin D2 or 25-hydroxyvitamin D3 as equivalent endpoints. The fact is that the metabolites of vitamin D2 and vitamin D3 are different molecules. Animals have evolved to use vitamin D3, and serum 25-hydroxyvitamin D3 is the biomarker that varies by sun exposure and latitude. Geographic studies of latitude and sun exposure have found reduced risk of colon cancer, breast cancer, diabetes and other cancers and chronic diseases at low latitudes with high levels of sun exposure. This protective association is based on the photosynthesis of 25-hydroxyvitamin D3 that results from sun exposure. This study found an elevation of two distinct intermediate biomarkers resulting from a dosing regime with two different forms of vitamin D. It does not demonstrate the equivalency of these compounds for prevention of colon cancer, breast cancer, multiple sclerosis, diabetes or other chronic diseases. Reduced risk of these diseases is associated with a daily intake of 2,000 IU of vitamin D3.
Edward D. Gorham, M.P.H, Ph.D.
Assistant Professor,
Dept of Family and Preventive Medicine
San Diego, CA 92186-5122
UNIVERSITY of CALIFORNIA, SAN DIEGO
MOORES CANCER CENTER
I would like to point out that D2 is often considerably more expensive than D3. So on a cost per effective IU basis should be the preferred choice.
Vitamin D2 rip-offs http://heartscanblog.blogspot.com/2007/11/vitamin-d2-rip-offs.html
I am totally confused. Can someone please tell me why Michael Holick, considered a D2/D3 guru and the "author" of the study above, also signed this letter http://www.grassrootshealth.org/_download/vitamin_d_consensus_letter_090907.rtf?
It is a letter by Dr Gorham above, who left a comment above regarding D3's superiority over D2. Dr Holick states D2 and D3 to be equivalent but then signed the letter by Dr Gorham that D3 is superior? I am trying to decide whether or not to take a whopping does of D2 as prescribed by my dr for D deficiency and can't seem to get a straight answer.
Whew, thanks for any feedback. I have been on this thing for days now and thought Dr Holick's article finally gave me my answer only to see that Dr Gorham and Dr Holick (time frames may play in here) as well state D2 does not attack the issue of cancers which all of us are greatly trying to avoid.
Feedback would really be appreciated...