5

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Vitamin D2 and D3: Equally Effective? Who's right?

Answered on August 19, 2014
Created July 12, 2011 at 5:20 PM

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?

27e79ef3308bb5f2d7bd04ee7eea7b79

(2038)

on May 17, 2012
at 11:52 PM

Wow. I wonder if my doctor actually knew that a prescription form of D3 exists, or if she just told me there wasn't one to make me go away. Thanks for the reply!

5ef574d7893bc816ec52e04139e9bc09

(6097)

on May 17, 2012
at 09:46 PM

^ Yes .

27e79ef3308bb5f2d7bd04ee7eea7b79

(2038)

on July 13, 2011
at 11:49 AM

Wow - what a comprehensive answer. As far as I'm concerned, this is the final nail in the D2 coffin. Thanks, Matthew!

61a27a8b7ec2264b1821923b271eaf54

(3175)

on July 13, 2011
at 06:00 AM

She never had any 'classic' symptoms of vit d deficiency. From WebMD: Symptoms of bone pain and muscle weakness can mean you have a vitamin D deficiency. For many, symptoms are subtle. Yet even without symptoms, too little vitamin D can pose health risks. Low vitamin D has been associated with the following: Increased risk of death from cardiovascular disease Cognitive impairment in older adults Severe asthma in children Cancer She has had a case of tendonitis that isn't healing and bouts of muscle pains she thought from statins that I talked her into quitting a few months ago.

667f6c030b0245d71d8ef50c72b097dc

(15976)

on July 13, 2011
at 01:35 AM

Citrate, many times available mainly as Natural Calm, does indeed have the lax effect if taken in larger-than-recommended doses. If you follow the directions in the bottle and go slowly you should be fine.

0bc6cbb653cdc5e82400f6da920f11eb

(19235)

on July 12, 2011
at 11:55 PM

@akman, It seems that some D2 would be naturally present in your body if you eat wild mushrooms that that had sunlight on them.

0bc6cbb653cdc5e82400f6da920f11eb

(19235)

on July 12, 2011
at 11:55 PM

@akman, It seems that some D2 would be naturally present in your body if you eat wild mushrooms that that had sunlight on them. One wild mushroom tested in Finland aparently contained 16,000 iu of vitamin D2 per 100 grams of dry weight.

27e79ef3308bb5f2d7bd04ee7eea7b79

(2038)

on July 12, 2011
at 11:41 PM

Ah, fortunately citrate hasn't had that effect on me... yet. So basically once I'm in good magnesium status, I have a heightened chance of diarrhea from magnesium citrate?

27e79ef3308bb5f2d7bd04ee7eea7b79

(2038)

on July 12, 2011
at 11:39 PM

Interesting. Thanks for the links!

27e79ef3308bb5f2d7bd04ee7eea7b79

(2038)

on July 12, 2011
at 11:38 PM

I think I'll do the same thing - continue to take the D2 until it runs out, supplementing with D3 on the days of the week I don't take the D2, and continuing with D3 only once the D2 runs out. 8 is awfully low, though. Are there any physical symptoms that come with such low levels?

61a27a8b7ec2264b1821923b271eaf54

(3175)

on July 12, 2011
at 10:54 PM

From the link provided by mem: Vitamin D3 is real vitamin D, for it is the same substance as what is produced in human skin in response to sun exposure. Supplemental vitamin D3 is derived from either lanolin or cod liver oil extract and is the only form of vitamin D that should be used to treat vitamin D deficiency. Vitamin D2 is derived from fungal sources by activating ergosterol with ultraviolet light. It is not naturally present in the human body and may have actions within the body different to those of vitamin D3.

61a27a8b7ec2264b1821923b271eaf54

(3175)

on July 12, 2011
at 10:48 PM

Thanks for asking this! My wife got the exact same answer from her doctor. But she added that if she wanted D3 she'd have to buy it herself as there is no prescription D3. So her plan is to take the 50,000iu of D2 twice a week as directed, and on the other days take 5000iu of D3 we bought at the store. Her stinkin' level has been 8ng/ml for at least 4 years. She is prone to skin cancer so shuns the sun and is lactose intolerant to boot! She's been on OYS-CAL-D, a calcium supplement with a whopping 150IU of D2 for a couple years--the doc said, 'well you were getting a vit D supplement'

77732bf6bf2b8a360f523ef87c3b7523

(6157)

on July 12, 2011
at 09:58 PM

Citrate causes diarrhea for some people. Paul Jaminet mentioned in a comment on his blog that he thinks this might only be in people with good magnesium status. Some people seem to do better on glycinate.

Cbb1134f8e93067d1271c97bb2e15ef6

on July 12, 2011
at 09:53 PM

You're welcome. Healthcare often drags its feet too long in making important changes, but, eventually, they do come. However, your need and time is now, so luckily making the change you need for yourself won't break the bank!

A727956fa3f943057c4edb08ad9e864e

(4183)

on July 12, 2011
at 09:43 PM

Holick, the vitamin D researcher. Here's the paper. http://www.ncbi.nlm.nih.gov/pubmed/18089691 Doses were so low that neither type raised the serum level above deficiency. In this paper: http://www.ajcn.org/content/87/6/1738.abstract it shows that d2 drops off much more quickly.

27e79ef3308bb5f2d7bd04ee7eea7b79

(2038)

on July 12, 2011
at 08:54 PM

I'm getting two questions answered in one! I've been taking magnesium citrate because I had no idea there were different forms of magnesium. Why Mg glycinate?

27e79ef3308bb5f2d7bd04ee7eea7b79

(2038)

on July 12, 2011
at 08:53 PM

Ah, why didn't my doctor just tell me that? Probably because she didn't know, as Jimbo said. Thanks for this little tidbit!

27e79ef3308bb5f2d7bd04ee7eea7b79

(2038)

on July 12, 2011
at 08:51 PM

10000 IU - a day?

27e79ef3308bb5f2d7bd04ee7eea7b79

(2038)

on July 12, 2011
at 08:50 PM

I'm wondering about "still works" because I was on 50,000 of vitamin D2 for 8 weeks. In that time, my vitamin D levels rose... from 20 to 27 ng/ml. That doesn't seem like a whole lot to me. What's "by holick," by the way?

27e79ef3308bb5f2d7bd04ee7eea7b79

(2038)

on July 12, 2011
at 08:48 PM

Yes, that's the link I sent to my doctor. I guess the Kaiser Pharmacy Committee doesn't have much faith in the Vitamin D Council :-) You're right about the cost of replacing what I have now with D3, thanks.

3a833804187fe8926214e6c0bd8a0766

(1023)

on July 12, 2011
at 07:58 PM

Seriously?! That's good to know, my sister was just prescribed Vitamin D, and I just assumed it was D3.

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7 Answers

best answer

12
0bc6cbb653cdc5e82400f6da920f11eb

(19235)

on July 12, 2011
at 11:40 PM

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.

The case against ergocalciferol (vitamin D2) as a vitamin supplement.

Some of the individual studies include:

Evidence that vitamin D3 increases serum 25-hydroxyvitamin D more efficiently than does vitamin D2.

This study, also by Vieth, found D3 showed 1.7-times greater efficacy than D2.

Vitamin D2 Is Much Less Effective than Vitamin D3 in Humans.

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."

Short and Long-Term Variations in Serum Calciotropic Hormones after a Single Very Large Dose of Ergocalciferol (Vitamin D2) or Cholecalciferol (Vitamin D3) in the Elderly

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."

Vitamin D3 Is More Potent Than Vitamin D2 in Humans.

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.

27e79ef3308bb5f2d7bd04ee7eea7b79

(2038)

on July 13, 2011
at 11:49 AM

Wow - what a comprehensive answer. As far as I'm concerned, this is the final nail in the D2 coffin. Thanks, Matthew!

10
3a833804187fe8926214e6c0bd8a0766

(1023)

on July 12, 2011
at 05:28 PM

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.

27e79ef3308bb5f2d7bd04ee7eea7b79

(2038)

on July 12, 2011
at 08:54 PM

I'm getting two questions answered in one! I've been taking magnesium citrate because I had no idea there were different forms of magnesium. Why Mg glycinate?

667f6c030b0245d71d8ef50c72b097dc

(15976)

on July 13, 2011
at 01:35 AM

Citrate, many times available mainly as Natural Calm, does indeed have the lax effect if taken in larger-than-recommended doses. If you follow the directions in the bottle and go slowly you should be fine.

77732bf6bf2b8a360f523ef87c3b7523

(6157)

on July 12, 2011
at 09:58 PM

Citrate causes diarrhea for some people. Paul Jaminet mentioned in a comment on his blog that he thinks this might only be in people with good magnesium status. Some people seem to do better on glycinate.

27e79ef3308bb5f2d7bd04ee7eea7b79

(2038)

on July 12, 2011
at 11:41 PM

Ah, fortunately citrate hasn't had that effect on me... yet. So basically once I'm in good magnesium status, I have a heightened chance of diarrhea from magnesium citrate?

4
A727956fa3f943057c4edb08ad9e864e

on July 12, 2011
at 06:32 PM

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.

27e79ef3308bb5f2d7bd04ee7eea7b79

(2038)

on July 12, 2011
at 08:50 PM

I'm wondering about "still works" because I was on 50,000 of vitamin D2 for 8 weeks. In that time, my vitamin D levels rose... from 20 to 27 ng/ml. That doesn't seem like a whole lot to me. What's "by holick," by the way?

A727956fa3f943057c4edb08ad9e864e

(4183)

on July 12, 2011
at 09:43 PM

Holick, the vitamin D researcher. Here's the paper. http://www.ncbi.nlm.nih.gov/pubmed/18089691 Doses were so low that neither type raised the serum level above deficiency. In this paper: http://www.ajcn.org/content/87/6/1738.abstract it shows that d2 drops off much more quickly.

27e79ef3308bb5f2d7bd04ee7eea7b79

(2038)

on July 12, 2011
at 11:39 PM

Interesting. Thanks for the links!

3
Cbb1134f8e93067d1271c97bb2e15ef6

on July 12, 2011
at 07:16 PM

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:

http://www.vitamindcouncil.org/about-vitamin-d/what-is-vitamin-d/what-is-vitamin-d/

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!

0bc6cbb653cdc5e82400f6da920f11eb

(19235)

on July 12, 2011
at 11:55 PM

@akman, It seems that some D2 would be naturally present in your body if you eat wild mushrooms that that had sunlight on them. One wild mushroom tested in Finland aparently contained 16,000 iu of vitamin D2 per 100 grams of dry weight.

0bc6cbb653cdc5e82400f6da920f11eb

(19235)

on July 12, 2011
at 11:55 PM

@akman, It seems that some D2 would be naturally present in your body if you eat wild mushrooms that that had sunlight on them.

27e79ef3308bb5f2d7bd04ee7eea7b79

(2038)

on July 12, 2011
at 08:48 PM

Yes, that's the link I sent to my doctor. I guess the Kaiser Pharmacy Committee doesn't have much faith in the Vitamin D Council :-) You're right about the cost of replacing what I have now with D3, thanks.

Cbb1134f8e93067d1271c97bb2e15ef6

on July 12, 2011
at 09:53 PM

You're welcome. Healthcare often drags its feet too long in making important changes, but, eventually, they do come. However, your need and time is now, so luckily making the change you need for yourself won't break the bank!

61a27a8b7ec2264b1821923b271eaf54

(3175)

on July 12, 2011
at 10:54 PM

From the link provided by mem: Vitamin D3 is real vitamin D, for it is the same substance as what is produced in human skin in response to sun exposure. Supplemental vitamin D3 is derived from either lanolin or cod liver oil extract and is the only form of vitamin D that should be used to treat vitamin D deficiency. Vitamin D2 is derived from fungal sources by activating ergosterol with ultraviolet light. It is not naturally present in the human body and may have actions within the body different to those of vitamin D3.

2
Fde416617fbb0ab67ccdaf40fa42c652

on July 12, 2011
at 06:21 PM

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.

3a833804187fe8926214e6c0bd8a0766

(1023)

on July 12, 2011
at 07:58 PM

Seriously?! That's good to know, my sister was just prescribed Vitamin D, and I just assumed it was D3.

27e79ef3308bb5f2d7bd04ee7eea7b79

(2038)

on July 12, 2011
at 08:53 PM

Ah, why didn't my doctor just tell me that? Probably because she didn't know, as Jimbo said. Thanks for this little tidbit!

1
A60bbe1b038a64d229c056c7c01ff02a

on May 17, 2012
at 09:34 PM

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:-)!

27e79ef3308bb5f2d7bd04ee7eea7b79

(2038)

on May 17, 2012
at 11:52 PM

Wow. I wonder if my doctor actually knew that a prescription form of D3 exists, or if she just told me there wasn't one to make me go away. Thanks for the reply!

0
Medium avatar

on July 12, 2011
at 06:28 PM

Just take 10000IU of d3 for a few weeks and then ramp it down to 5000IU. 5K got me to 85ng/ml, which I thought was a bit high, so I've decreased that to 1K 3x a day on non-sun days.

27e79ef3308bb5f2d7bd04ee7eea7b79

(2038)

on July 12, 2011
at 08:51 PM

10000 IU - a day?

5ef574d7893bc816ec52e04139e9bc09

(6097)

on May 17, 2012
at 09:46 PM

^ Yes .

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