Prescription vitamin D


Over-the-counter: $2-5 per month
Prescription: $120 per month

Fish oil:

Over-the-counter: $3-6 per month
Prescription: $120 per month

Vitamin D:

Over-the-counter: $2 per month
Prescription: $70 per month

With vitamin D in particular, the prescription form is vastly inferior to the over-the-counter preparation. This is because the prescription form is ergocalciferol, or vitamin D2, not the effective human form, vitamin D3 or cholecalciferol.

When you're exposed to sun, what form of vitamin D is activated in the skin? It's all vitamin D3, no vitamin D2 whatsoever. Vitamin D3 is also far more effective than D2. People taking D3 (as long as it's oil-based) easily obtain healthy levels of vitamin D in the blood. People taking 50,000 units per day of D2 (the recommended quantity) remain miserably deficient, with minor increases in vitamin D blood levels. In short, D2 barely works at all. D3 works easily and effectively.

Moreover, D2 is the plant-based form. It is a form not found naturally in humans. D3 is the mammalian form, the same found in humans that exerts all its biologic benefits.

Then why is the prescription form of vitamin D2 (brand names Driscol and Calciferol) more expensive?

It's the same old pharmaceutical industry scam: Look for something patent protectable, regardless of whether it's superior to the non-patent protectable product, then sell it for exagerated profits. Though it is inferior and the science and clinical experience prove that it's inferior, you can still fool lots of people, including prescribing physicians. So what if you only make $50 or $100 million?

Don't fall for it. Prescription doesn't necessarily mean superior. In fact, the prescription form may be significantly inferior, as with vitamin D2. But the pharmaceutical industry carries such power and persuasion, who's going to know?

Comments (32) -

  • Anonymous

    6/23/2007 12:10:00 PM |

    I guess it could be said that a flaw some have is a willingness to take advantage of the uneducated.  

    On the niacin, my guess is that the over the counter Slo Niacin is manufactured by the same company in the same facility as the prescription form.  The machines used would be different as the FDA wants this, but the manufacturing procedures and source product would be the same.  I don't know this for a fact, but it would not surprise me if it were true.  

    For fish oil, there are only a couple facilities in the world that manufacture fish oil.  The products these facilities sell are pretty much all the same in quality.  Everyone buys from the same places.  The facilities that encapsulate pharmaceuticals often times also manufacture health foods in the same plant.  The exact machines used for encapsulating pharmaceutical fish oil and store shelf fish oil will need to be different for government purposes but basic manufacturing practices followed will be about the same.

    I was in a unique situation to witness a Germany company sell a product as a health food - and at the same time was going through the FDA drug approval process with the same exact patent protected product.  The product never did make it through testing in the end.  Phase 3 (I think that is what it is called) human studies at the Cleveland Clinic were a bust as too many people stopped taking the product. (Reportedly the product worked so well that people stopped taking it as they felt healed.)  I remember the German company planned to make “large” amounts of money off of their product if it passed testing as they would be able to charge a premium.  After testing fell through they decided to not try again.  A large American firm took on their product and placed it into every store in America, - and that was good enough for them.

  • Edward Hutchinson

    6/23/2007 1:49:00 PM |
    The case against ergocalciferol (vitamin D2) as a vitamin supplement provides more information which may interest some.
    Risk Assessment for Vitamin D shows that up to 10,000iu daily produces no observable adverse events but readers should note that actual harm occurs is 40,000iu are consumed daily.
    However as you body uses only 4000iu daily there has to be good reason to take more than 4000iu daily.

  • BarbaraW

    6/23/2007 2:06:00 PM |

    Dear Dr. Davis,

    I've been reading your blog for sometime, since I found the link on Regina Wilshire's blog. I've learned a lot and want to thank you for sharing your insights and expertise with everyone. I imagine (and hope) that there are many, many more people reading it than are posting. I think what you and your colleagues are doing with Track Your Plaque is phenomenal. Interesting that there seem to be none of these services in New England, that bastion of tradition.

    I've been fascinated by your articles on Vitamin D.  In looking around at Vitamin D3 (cholecalciferol) to purchase online (I can't find gelcaps locally), I came across the "Wilderness Family Naturals" web site.  In their article on cod liver oil ( ), they state:
    "Cholecalciferol is the form found in vitamin supplements and fortified dairy products and not the hormonal form of vitamin D, namely 1,25-dihydroxycholecalciferol."
    The also state: "The form of vitamin D that we get from supplements is not fully active."

    Can you talk about this for us?

    In any case, my question is: can't I just take my cod liver oil to get my Vitamin D? Do I need the gelcaps of D3 in addition?

    Thanks again,

  • Dr. Davis

    6/23/2007 10:04:00 PM |

    Wow! Thanks for the helpful commentary.

  • Dr. Davis

    6/23/2007 10:09:00 PM |

    It's really very simple once you start checking blood levels on everybody--you quickly begin to learn what works and what doesn't.

    Vitamin D3 (cholecalciferol) is what you need. Don't be confused by the comment about the "real" form, 1,25-diOH-vitamin D3. This is a kidney metabolite. We all still need vitamin D3.

    It's best to find D3, not cod liver oil. I remain skeptical about the safety of cod liver oil due to some reports of preparations with excessive pesticide residues.

    Try or look for Carlson's preparation, both 2000 unit gelcaps of D3.

  • Cindy

    6/24/2007 9:06:00 PM |

    I take D3 and have been for at least 3 months. I've been taking 3000iu/day and just had a blood test that indicates my blood level is only 33 (22 - 67 is the reference level).

    I'm out in the sun at least 15 min a day, not including driving, walking to and from, etc. much Vit D should I be taking? I believe you recommend a level of 50-60?

  • Dr. Davis

    6/24/2007 11:24:00 PM |

    We commonly use 5000-6000 when situations like this arise and generate desirable levels. Also, the values of "normal" in the reference range you provide suggests that your laboratory also runs an outdated method of measurement. (The newer methods tend to show "references ranges" of 20-100, or something close to that range.)

  • Cindy

    6/25/2007 4:22:00 AM |

    Thanks!! I've made several changes recently thanks to your posts!!

  • Mike

    6/26/2007 6:25:00 AM |

    Hi Dr. Davis,
    I see both Vitamin D and Vitamin D3 supplements being sold:

    Vitamin D

    Do I need to assume that supplements labeled as simply Vitamin D are, in fact, D2?  Are there other forms that it could be?

  • Dr. Davis

    6/26/2007 12:33:00 PM |

    No, you can not assume D is D3.

    Always look for:
    1) gelcaps, not tablets
    2) D3 or cholecalciferol
    3) Never D2 or ergocalciferol.

    Those little attentions to detail will help a bunch and ensure you get the right stuff.

  • Mike

    6/26/2007 6:19:00 PM |


  • Anonymous

    7/25/2007 8:32:00 AM |

    I was diagnosed with a defiency in vitamin D in january . My total level was 12ng/mL . I started taking supplementation, 800 IU daily of Vitamin D3 (cholcalciferul), and a Centrum multi-vitamin which has another 400 IU . I took that for over 6 months. I just had my level checked again . It is only 15ng/mL still !
    How much D3 should I be taking ?
    And what would be a good target for a 31 year old male ?

  • Dr. Davis

    7/25/2007 12:04:00 PM |

    There's no "one-size"fits-all" in dose for vitamin D. However:

    1) The vitamin D in multivitamins doesn't work at all.

    2) You're therefore taking 800 units per day, the dose for a small child.

    3) Most adults require 2000-6000 units per day. The D must be in capsule form, not tablet.

    4) In the Track Your Plaque program, we aim for a blood level of 50 ng/ml.

  • Anonymous

    7/26/2007 5:43:00 AM |

    Thanks, Dr.

    1) Can you expand on why that is re. multi-vitamins inefficacy of vitamin D ? Does this apply only to the vitamin D in them ?
    Are the liquid forms of multi-vitamins any better than the tablets (eg. centrum liquid) ?

    2-3) I thought according to the FDA, the recommended daily dose was 400 IU for an adult and the safe dose was 2000 IU. How did you come up with your numbers ?

    3) You guessed it - I had been taking Vitamin D in tablet form only. I can certainly believe that they were not effective given my test results. But can you explain why the tablet forms don't work ?

    Tonight I looked for vitamin D in liquid form . I had to go to 4 places - Costco, my Kaiser pharmacy, Longs, and finally Walgreen's, which had some softgels from fish oil. I bought 100 softgels of 1000 IU each for $7.99.

    The tablets I have are Nature made brand. I have about 300 left. As far as tablets go, how do you rate them ? Would you just throw them away and just take the gels ? Or take some gels and tabs ? I hate to just waste the tabs.

    4) Thanks !

  • Dr. Davis

    7/26/2007 12:30:00 PM |

    Please refer to the several previous posts under "Vitamin D" or our extensive discussion on the website.

  • Dr. Davis

    7/28/2007 2:50:00 PM |

    Vitamin D should always be either "D3" or cholecalciferol, NEVER "D2" or ergocalciferol, since D2 exerts negligible benefits.

    If your preparation fails to specify which form, look for another that does.

  • Ava

    10/10/2007 8:12:00 PM |

    Hello I'm a vegan from Germany and like to respond to the argument that is circling through the web relating to D2. Since I'm vegan don't use D3 since that is produced by irridating butchers-wool with UV-light, an information that is often left out when touting this version of vitamin D as the "natural" one. Because of all the negative rap D2 has gotten, it has now in fact disappeared as a supplement in the EU, effectively starving vegans and other vegetarians of vitamin D. I was thus forced to look for alternatives to have my winter supply of vitamin D. What I do is grow my own delicatessen mushrooms right here at home and either dry them in the sun or irridate them with the Utra Vitalux 300 Watt UVB - Lightbulb after harvest which makes them a very rich source for vitamin D2.  Now here comes the interesting part. My previously utter deficient 25(OH)D below detection level, measured at the end of summer -I'm not the outside type and almost never get enough UV-exposure from sunlight- has after a year gone up to 105 nmol/L. Given that I have nowhere near enough sun exposure, and as a vegan no other dietary source of vitamin D, it is clear to me that the vitamin D2 from my sun-dried or irridated mushrooms is responsible for my recovery from hypovitaminosis D.

    Now I don't know if there's a difference of vitamin D2 in mushrooms or the pharmacological D2 in pills, all I know is that Vitamin D2 is *my* primary source of vitamin D and it's giving me excellent levels of 25(OH)D.

    What I find highly irritating is the meme like argument flying around that vitamin D3 is the one "naturally appearing in the body". Duh. Vitamin D2 is also converted into vitamin D3 so the fact that D2 is not "naturally in the human body" should be as relevant that Vitamin C is not "naturally in the human body" and has to by sourced from diet. There are many nutrients that are "not natural" in the human body and which we need to source from diet, for example the essential amino acid. Besides, since when does "natural" equate to being good? If a Uranium miner has "natural" radioactivity in his body because he is exposed to it during work, is that good? I don't think so.

    The reason I'm irritated is because the information about vitamin D2 being bad (when that is, at least in my case *not* true) has real implications and discriminatory effect on vegans and other vegetarians because not everybody of us has the patience and curiousity to produce their own Vitamin D at home, and perhaps some people don't enjoy eating mushrooms.

    There is one more point and then I'll end my rant. Every time us vegans were informed that a particular plant based nutrient like vitamin A (beta-carot.) or iron was inferior because it has a lower bio-availability, later research discovered that that lower bio-availability has actually real benefits. I wouldn't be surprised if the same appears to be true for vitamin D2. I have already come across research which noted one of the D2 metabolites to have anti cancer properties, although this study is based on non-human animals meaning it has little to no relevance to humans and is based on the exploitation and death of rats.

    For those who (despite reading this on an electronic network of computers) lay any importance on _naturality_ regarding nutrients, you may want to consider my method of just drying mushrooms in the sun. That's certainly more natural than killing sheep, stripping the hair grease of their wool and irridating that with UV-B light, which is the standard method of how vitamin D3 is produced - a byproduct of butchers waste.

  • Dr. Davis

    10/10/2007 9:40:00 PM |

    Fascinating solution!

    However, I stick by my claim that, for most people, vitamin D2 supplementation does not work. I have seen many people on as much as 50,000 units of D2 per day with zero or near zero levels of conversion to the active D3, all proven by blood levels.

    However, for a vegan, I do not have any useful non-animal solutions beyond getting sun.

  • Anonymous

    2/14/2008 8:14:00 PM |

    My Vitamin D levels, when first tested, were 12.  I have been using a Vitamin D lamp to try to raise the levels, which are now 32-33.  Initially, I took Puritan's Pride Vitamin D, which made me feel like a new person, but I quickly learned that it interfered with the efficacy of Cytomel, which I take because Synthroid interferes with yet a different medication.  Do you know of any form of Vitamin D that might not interfere with Cytomel?  

    Thank you.

  • Anonymous

    4/4/2008 5:47:00 PM |

    I just found out my vitamin D level is abysmally low from a blood test. My endocrinologist gave me a prescription for 50,000 units of vitamin D.  After reading about the subject here, I don't know whether to fill the prescription or go the the health food store and get a bottle of vitamin D3 capsules and disobey doctor's orders. We are investigating whether I have disturbances in my cortisol levels.  So far, testing has shown very low morning cortisol levels.

  • Anonymous

    5/6/2008 8:00:00 PM |

    I went from sickly to healthy from taking 50,000IU (once a week) of Calciferol, proven by my recent bloodwork.  My D level was 18 in November,  and 4 months later it was 38!!!  Taking D2 has changed my life and I continue to take it without hesitation or reservation.

    I have read that I should be taking a cal/mag supplement to increase absorbtion but I have not done so . . . your thoughts please.

  • Anonymous

    7/25/2008 6:43:00 AM |

    Maybe the lab you use for blood tests isn't DEQAS certified, and isn't accurate.  I don't know how else to explain why a recent study contradicts what you're saying about D2:

  • Anonymous

    8/5/2008 11:38:00 AM |

    Hello, can you tell me what form of D3 is best and why.

  • Anonymous

    11/7/2008 2:11:00 PM |

    Ergocalciferol (D2) has a kenetic half life of 10 days.  Calcitriol (D3) has a half life of 3 days. I am surgically hypoparathyroid and replaced 100% of that function with calcitriol or ergocalciferol for 30+ years. I find the D3 form is smoother on my body, until I forget to take my dose on any particular day. Then my mood, energy, stamina, sense of well being etc noticably deteriorate. I lived quite easily on D2 for nearly 28 years until medicare decided this life essential medication was a non life essential vitamin and forced a change to the more expensive calcitriol they would pay for. So now I painfully die in 10 days without D3 instead of 30 days if taking D2. This is germane when the price of ergocalciferol in 1991 was $1.99/100 50000IUs dose. After several years of repeated "offshore supply problems" the price is now $125/100 forn teh identical medication. Sometimes I'd drive 75 miles to another pharmacy (dealer - lol) to refill the D2 when the supply dried up. On correct fo the supply problem the price would double or triple (WTF???). Oh well - rather that a "DNR" I insist on a "JSM" (just shoot me).

  • Carminal

    11/8/2008 12:23:00 AM |

    Hi everyone,

    Firstly, I must say I agree with ava reactions being irritated above, even if not being vegan myself, but vegetarian.

    I would like also to point out that health is definitly not numbers on a paper coming from tests but is how we can feel and act.

    Good health is about feeling balanced and in a state that allows personal accomplishment. It is not, not at all, about obtaining or aiming a level of that molecule or this other one in a blood test.
    You can take two people with same amount of that molecule, or with similar tests results and having one feeling very healthy and being really so and the other one being and feeling desperetly ill. Blood tests reflect only very poorly what is really happening in the vast universe of our cells and tissues. It does not indicate at all how plenty of important biological reactions are going in us.

    It makes me smile when I read 50,000 IU of D2 did not increase D3 levels. When you place carrots in your dish, you do not have sprouts !! The purpose of taking D2 is not about raising D3 and D3 metabolites levels but D2 and D2 metabolites ones. D2 and D3 molecules react in same biological fields, and D2 is beeing used with success for decades. It is not honnest to omit that and to pretend D2 is worthless because D3 levels do not raise : it is a false demonstration.

    In my view solar exposition is the most important factor for everyone, but when not getting enough D from sun, the plant-form D (D2) is perfectly suiting. I have never read any animal study that tends to show D3 supplementation is preferable to D2; on the contrary toxicity is shown to be a lot greater with D3 hypervitaminosis than with D2 hypervitaminosis (a lot more calcifications with D3 than with D2). Plants represent the reference in food because everything we need, even B12 for example, can be found in the plant kingdom; that is not the case if the animal kingdom is taken as food. Then ask your intuition about D2 and D3 being the most desirable form of Vit. D when not receiving enough sun...

    Readers should remind that there is two different 25(OH)D : the one with D2 and the one with D3, and also two 1,25(OH)2D. Measuring the D3 forms (most commonly measured in blood tests) is meaningless if you take D2 supplements. It is NATURAL having in the blood less 25(OH)D in its D3 form during winter than during summer because at that time there is less sun activity. Correcting lowering Vitamine D activity during winter with D3 supplementation rather than with D2 is illogical and unatural.

    R. Jehl
    Naturotherapist in France

  • Anonymous

    11/30/2008 10:58:00 PM |

    Individualized Vit D supplementation is necessary. The arguments regardind D2, D3, single Hydroxy and double hydroxy depend on your body and its current disease status. For example, giving a D2 or D3 to a patient without kidney function is useless because they cannot convert it to the ACTIVE form of 1,25(0H)2D3. Kidney patients must take activated or the final form of vitamin D 1,25(0H)2D3. Liver dysfunction patients cannot convert the D3 to the single hydroxylated form, which the kidney needs in order for its metabolism. So, really, blank statements as given by the French provider indicating D2 for all is FALSE. Look up the metabolic pathway. If you are stone cold normal and only have low Vit D, then you can take either form of regular D2 or D3. If you have a disease, GI malabsorption, liver or kidney disease, granulomatous disease etc you should consult a professional to guide your dosage for proper results. I do like combining some fast acting forms with some slower acting forms to help folks feel better faster and then long term treating with slower forms if they can metabolize them. Everyone is unique and sometimes trial and error are required.

  • Anonymous

    12/22/2008 6:32:00 PM |

    I have read through these posts with interest. I am new to this site, looking for a solution to my 'no beef' diet and insufficiencies in Vitamin D (3 mostly). I am on synthroid, but never knew of the Vitamin D correlation.

    I find that in the US there appears to be NO 50,000 Vitamin D without bovine capsules. I cannot find a veggie tab surrounding even the D2.

    Can anyone advise where I might 50,000 units of Vitamin D3 with no 'cow' gelatin coating?

  • Anonymous

    2/4/2009 1:33:00 PM |

    Do you have any recommendations for those who are vitamin D deficient but cannot tolerate oil based capsules but have no problem with fortified foods?  Is the UV lamp a safe alternative?  Is there a powder form of D that is effective?

  • Anonymous

    2/6/2009 8:52:00 PM |

    I've read this discussion with a great deal of interest.  I've been supplementing with Vital Nutrients capsules which are vegetarian.  They make 2000iu capsules and 5000iu capsules.

  • Ava

    12/26/2009 1:17:19 AM |

    Hello this is Ava again from Germany, I posted a long rant into this thread some while ago.

    I'd just like update that I've switched from irradiated mushrooms to a vitamin D2 supplement as drops ( Sterogyl 2,000,000 ergocalciferol ) and my 25(OH)D levels are really nice in winter at 156 nmol/L or 62 ng/ml! In France it's availalbe without perscription and we've been able to get it Germany too. It's very cheap around 2 Euro for 400,000 IUs despite the name. I started out with 13 drops / 5200 IU for 14 days, then I took a single mega dose of 300,000 IUs. Since that I've been taking 70.000 IUs once a week. I'm very tall at 6' flat and this is the dose my body needs to achieve good levels.

    It's also possible to just keep on taking 3500 to 5000 every day, however it then takes much longer to reach desired serum levels.

    If you have access to this cheap product and take 5200 every day, the 2.50 Euro or so will still last you almost 3 months.

  • josephmoss

    7/24/2010 7:37:50 AM |

    Vitamin D3 Iu:

    NOW Vitamin D softgels supply this key vitamin in a highly-absorbable liquid softgel form. Vitamin D is normally obtained from the diet or produced by the skin from the ultraviolet energy of the sun. However, it is not abundant in food. As more people avoid sun exposure, Vitamin D supplementation becomes even more necessary to ensure that your body receives an adequate supply. Vitamin D3 Iu on discount at

    For more details please visit:

  • buy jeans

    11/2/2010 7:55:30 PM |

    When you're exposed to sun, what form of vitamin D is activated in the skin? It's all vitamin D3, no vitamin D2 whatsoever. Vitamin D3 is also far more effective than D2. People taking D3 (as long as it's oil-based) easily obtain healthy levels of vitamin D in the blood. People taking 50,000 units per day of D2 (the recommended quantity) remain miserably deficient, with minor increases in vitamin D blood levels. In short, D2 barely works at all. D3 works easily and effectively