Vitamin D3 Blog

Everything you need to know about Vitamin D3 (cholecalciferol).

Vitamin D2 vs. Vitamin D3

with 9 comments

Vitamin D3 is manufactured by the body when human skin is exposed to direct sunlight. It can also be obtained through certain foods, as well as supplements. The main difference is in D3′s superior bio-availability, which lends to better absorption of the nutrient and enhanced health benefits directly associated with absorption factor and the fact that Vitamin D3 is a more naturally occurring form of the nutrient.

According to Nurse Practitioner Pam Egan, Vitamin D3 is “not to be confused with inactive Vitamin D2.”

Two Major Types of Vitamin D

Although there are a total of five different forms of Vitamin D, only two are commonly used in supplements.

  1. Ergocalciferol (Vitamin D2) - A synthetic form of Vitamin D. This is the form found in most nutritional supplements. D2 is substantially less bioavailable than D3.
  2. Cholecalciferol (Vitamin D3) – The naturally occurring form of the D Vitamin. This is the same Vitamin D manufactured by the human body when skin makes contact with direct sunlight. Cholecalciferol is five-times (or 500%) more bioavailable than Ergocalciferol, which means that D3 is converted into a usable form by the body at a rate five times faster than is the case with D2.

Another drawback with Vitamin D2 is that it has a much shorter shelflife than does D3, and its metabolites do not bind well with proteins, rendering it that much less effective than the alternative.

Many recent studies have suggested that Vitamin D2 should no longer be classified as a nutrient appropriate for supplementation and/or fortification in foods. Despite this, it continues to be the most common form of Vitamin D available in supplement form on the market today.

In conclusion, based on all of that documented above, it is clear that Vitamin D3 is a far superior form of Vitamin D than is D2, and anyone who takes their health seriously should strongly consider double-checking to make sure they’re getting the good stuff (Cholecalciferol) as opposed to the inferior Ergocalciferol when shopping for Vitamin D supplements.

Written by Admin

May 7th, 2010 at 10:54 pm

9 Responses to 'Vitamin D2 vs. Vitamin D3'

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  1. Hi!
    Very good idea to explain this. Just as a coincidence… I was asked this question recently also and that in a Health food store!
    I’m an eternal student (as a hobby) of alternative medicine and a big fan also, so I new the answer, but… when I look at it from humorous side… was my knowledge “visible” so much? :)
    Person could asked store’s people, couldn’t she?
    Well, glad I was of help anyway and again thanks for informing public better. There is never enough of that, especially when truthful.
    Best regards,


    21 May 10 at 1:18 pm

  2. I really wanted to construct a small note to thank you for some of the wonderful steps you are writing here. My particularly long internet search has finally been rewarded with really good concept to go over with my co-workers. I would repeat that many of us site visitors actually are very much fortunate to live in a decent network with so many marvellous individuals with very helpful suggestions. I feel extremely fortunate to have seen your site and look forward to really more awesome moments reading here. Thank you once more for everything.

    Bonnie Vergo

    10 Sep 11 at 2:15 pm

  3. My problem is that I am a vegetarian. Most supplements, including D3, come with gelatin. I ended up with D2 because it is vegan. If D3 is from sheep’s wool, I would be ok with that, because the animal isn’t harmed. However, I cannot find a D3 supplement that is packaged without gelatin. Joanne

    Joanne McBirney

    15 Feb 12 at 1:23 pm

  4. I would like to make a comment and see if this makes sense to you. I take D3 1000u once to three times a week. I have been told over the last 3 years that my d level is still deficient or insufficent and I have been prescribed d2 50,000u for three months at a time to boost my level but it never seems to last. Why is that? Because of these short-term treatments, I inadvertently discovered that the d2 improves my depression, muscles aches, increase my energy,reduce my belly fat and chronic eye irritation. I do not get colds as often if at all in the winter months. I seem to know when my d is low because of these recurrent At first, I thought it was just a coincidence, but have come to find definite at least with me. I wonder if anyone else has has noticed this? I have tried boosting my over the counter d3 but the effect is not the same at all. Can d2 be obtained in pill form over the counter? I do not think my doctor believes me.


    4 Mar 12 at 8:48 am

  5. Are you sure you’re not confusing D2 and D3? All available evidence on the subject suggests that if anything, the exact opposite of what you’ve stated here should be the case.

    If in fact you’re finding better results with high doses of D2 than you are with normal doses of D3, it may be time for you to try a higher-quality brand of supplement (OTC brands in drugstores and grocery chains are not the same as those manufactured by top-of-the line nutriceutical laboratories.

    My recommendation would be to give either Douglas Labs, Biotech or Egan Wellness Clinic brand Vitamin D3 Supplements and see how you do with a superior supplement made with better ingredients and made with better equipment using a better process than what you’ll find in the grocery store or pharmacy.


    5 Apr 12 at 2:27 am

  6. Joanne, Egan Medical now offers a vitamin D3 supplement that comes in the form of sublingual (under-the-tongue) drops that you use with an eye-dropper like tool.


    5 Apr 12 at 2:40 am

  7. What about the recent studies from Boston University School of Medicine that has shown D2 and D3 are basically equal in maintaining and raising Vit D levels?


    11 Apr 12 at 7:25 pm

  8. @Rob

    They were either motivated by grant money that was promised on the condition that the outcome be consistent with the predetermined conclusion that suits the financier’s agenda, or the scientists simply got it wrong in one form or another. I haven’t read the studies you reference, assuming they exist.

    I have however read no less than three dozen which all conclude definitively that D3 is infinitely superior to D2, with some even going so far as to declare D2 unfit for human consumption as a dietary supplement.


    3 Jun 12 at 5:51 am

  9. J Cimino’s comment on FDA attacks on supplements that are unlikely to really be harmful and which have had no reports of adverse effects as compared to others, is right on.

    Cherish Rehnberg

    8 Feb 13 at 8:45 am

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