On this thread http://paleohacks.com/questions/50518/hack-my-wifes-vitamin-d-deficiency/50531#50531 , akman asked about his wife's vitamin D deficiency and most replies included the need for his wife to be taking D3 supplements, not D2. Since my doctor prescribed D2 for my low vitamin D levels, I decided to contact her and ask for a Rx for vitamin D3 instead. I included some links I found here, such as the one someone posted on the above thread to the vitamincouncil website.
My doctor's reply: Hello, For Vitamin D deficiency the recommended formulation is the one I prescribed. The Kaiser pharmacy Committee reviews all the evidence and the data is not conclusive regarding one vitamin D supplementation being superior to another. XXXX, MD
I just saw another thread here where people say to take D3 - http://paleohacks.com/questions/46473/vitamin-d2-d3-what-are-the-differences#axzz1RucVPUMq
Now, my question: Who's right? Do I throw out my vitamin D2 and buy D3 supplements by the truckload (to reach the 50,000-uit level of D2 that I was prescribed? Or do I trust that the Kaiser Pharmacy Committee knows their stuff?
Most evidence I have seen indicates that vitamin D3 is more potent than vitamin D2 as a supplement.
Reinhold Vieth, a well known vitamin D researcher produced a review article on this subject back in 2006 detailing the evidence for D3 vs D2 at that time.
Some of the individual studies include:
This study, also by Vieth, found D3 showed 1.7-times greater efficacy than D2.
This study found: that: "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."
In this study elderly patients were given a single dose of 300,000 iu of vitamin d. They concluded "Cholecalciferol is almost twice as potent as ergocalciferol in increasing serum 25(OH)D, when administered either by mouth or im."
This study gave 50,000 iu once a week of either D2 or D3. They conclude: "D3 is approximately 87% more potent in raising and maintaining serum 25(OH)D concentrations and produces 2- to 3-fold greater storage of vitamin D than does equimolar D2."
I only know of one study by Michael Holick, another well known researcher on vitamin D who has written a book on the subject, that found that both the D3 and D2 forms were equivalent. However he only used a dose of 1000 iu per day and at this dose differences between the two forms my not show up. There appears to be some dissagrement between Holick and others working on the subject. I find it strange that Holicks papers on the subject appear to ignore almost all of the other studies showing that D2 is less effective. Vitamin D2 Is as Effective as Vitamin D3 in Maintaining Circulating Concentrations of 25-Hydroxyvitamin D.
Vitamin D2 has been the form used as a prescription medication for a long time. D2 has also been the form used to fortify foods like margarine and milk for many years. There is a great deal of inertia behind such practices and the pharmaceutical companies that produce vitamin D2 have little incentive to change things. Doctors are often limited in which form they can prescribe.
Vitamin D2 does work, but it appears not as well as the same dose of D3. Vitamin D3 supplements are not expensive now and are available to most places. If you want you can keep taking the D2, see if they work and when they have corrected the levels switch to your own supply. Or just buy your own now.
Everything I've read has mentioned D2 isn't as effective. Do you really need "prescription strength?" If it's something like 50,000 IU's a week, why not take 7,000 IU's a day? NOT a recommendation (I'm not a doctor) I'm just asking.
My doctor said she recommends everyone take a Magnesium supplement... when I asked why kind of Mg she looked like a deer in headlights.
Me: "I've read that Mg Oxide isn't absorbed and can even be harmful, so I take Mg Glycinate. it makes me sleepy too."
Doctor: "uhhhhh... What?"
I question how many doctors know the differences in dietary supplements (even prescription strength) when it comes down to it.
I did a lit review for college on vitamin D.
D2 is less effective but still works, there was one paper that showed it to be equally effective (I think by holick) but it still dropped off serum levels much more quickly.
I had posted this link in the comments on that thread. I'd say the Vitamin D Council is pretty high up there as a very reliable source and that there is a BIG, BIG difference between D3 and D2. For one thing, D2 doesn't occur naturally in the body and D3 does.
Info for your own decision:
Bottom line is also that even replacing the D2 with D3 is not a big, expensive deal.
Best to you with whatever plan you come up with!
There is no prescription D3. If you want a prescription vit d then it will be D2, which is not as effective. That is why most people use an OTC supp like Carlson's D Drops, which are very inexpensive when purchased online.
My son & his wife were prescribed 150,000 IU of Vitamin D3 in the gelcap form yesterday! So, doctors can definitely prescribe this! My son has taken all kinds of vitamins because he has always been foggy headed & had a "sense of gloom & doom feeling"...like a cloud was over his head! My son's vitamin D level was 27 & he is 28 years old & takes in a lot of sun! The Doctor told him & his wife to take this dosage for one month & to have their levels checked again! He said they would be taking this vitamin for at least one year, until the level was up to 100%! After that, I am assuming that he will take lower Vitamin D3 gelcaps daily over the counter! My son said this gelcap was what he had been searching for all of his life! It immediately lifted the depression & foggy minded feeling! He said his mind felt light & that he had never felt this good in his entire lifetime! It is definitely the "miracle vitamin" for him! Also, his wife loves it as well! She & I both call it the "happy pill" because it instantly lifts depression & makes us feel carefree & makes us laugh:-)! I was an (11) & my doctor prescribed me the synthetic form...Vitamin D2 150,000 IU pill form, once weekly for 5 weeks! Took it one time and hated it!...This pill had horrific side effects, so I went to the Dollar Store & bought the Vitamin D3 gelcaps..They came in 2,000 IU, so I take 2 at once! I would prefer the 5,000 to get my levels up quicker, but I guess that will have to wait until I visit Walmart;-)! Anyhow, my depression has lifted & I feel soooooooo much better & that is why I am calling it the "happy pill"..lightens, brightens up my day & gives me much laughter! How much better could it get than that? Love Vitamin D3 gelcaps:-)! They are the natural form that our bodies make! Be Blessed:-)!
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