The (Huge) Difference Between Vitamins D3 and D2 And Why You Should Never Take D2 - Save Our Bones

Today I am going to share with you some crucial but little-known information about Vitamin D that your doctor simply won’t tell you.

You see, if your blood test results have shown that you are Vitamin D deficient, chances are your doctor prescribed Vitamin D2 (ergocalciferol) supplements instead of D3 (cholecalciferol).

Today, you’ll learn the difference between these two forms of Vitamin D and why you should take D3 and never D2.

Study Proves The Inadequacy Of Vitamin D2 (And The Superiority Of D3)

A report published in The American Journal of Nutrition points out the very clear difference between Vitamin D3 and Vitamin D2, the latter, the “form of vitamin D used in major preparations of prescriptions in North America.”1 Vitamin D2 is in fact not the bioavailable equivalent of D3.

“Vitamin D2, if given in high enough doses, prevents infantile rickets and is capable of healing adult osteomalacia. However, the inefficiency of vitamin D2 compared with vitamin D3, on a per mole basis, at increasing 25(OH)D is now well documented, and no successful clinical trials to date have shown that vitamin D2 prevents fractures.”1 (emphasis added)

The study goes on to state that

“… ergocalciferol should not be regarded as a nutrient suitable for supplementation or fortification.”1

Here’s why. There are several biological mechanisms that contribute to the superior absorbability and efficacy of Vitamin D3. In the liver, thanks to a particular hepatic enzyme, Vitamin D3 is more readily metabolized into a bioactive form of D that is easily converted to its hormone form in the kidneys. It takes much longer to make this hepatic conversion with Vitamin D2.1

In fact, D2 and D3 are metabolized so differently that they result in “the production of unique biologically active metabolites.”1

Clearly, these forms of Vitamin D are simply not the same. Hence the study’s conclusion that ergocalciferol should not be used as a supplement.

So Why Are Most Prescription Supplements Vitamin D2?

You may be wondering how Vitamin D2 supplements came to be the mainstream protocol in the first place. We need to go back almost 100 years to find the answer.

Back in the early 1920s, scientists discovered that exposing foods to ultraviolet light produced Vitamin D2. Thus the manufacturing of this vitamin was born, and the process was sold to what would become Big Pharma. Drug companies then produced and sold this medicinal form of Vitamin D2 to the public and to doctors.

Less than 10 years later, in the 1930s, scientists noticed that Vitamin D2 did not seem as effective in the treatment of rickets in children (the primary use of the vitamin in those days) as the Vitamin D3 in cod liver oil.

Subsequent studies showed mixed results, and not surprisingly, in 1949 the World Health Organization declared that differences between the two forms are “minimal”. But recent research clearly shows that they could not be more wrong!

The Dangers Of Vitamin D Toxicity

One of the primary dangers of Vitamin D2 is that there is a fine line between an effective therapeutic dose and toxicity. In fact, prescription Vitamin D2 carries a warning that the dosage should be adjusted as soon as there is notable improvement in D levels.

The popular prescription Vitamin D2, Drisdol, carries the following warning (among others):

“Dosage levels must be individualized and great care exercised to prevent serious toxic effects. IN VITAMIN D RESISTANT RICKETS THE RANGE BETWEEN THERAPEUTIC AND TOXIC DOSES IS NARROW.”2

Why risk poisoning when there is a completely safe way to get all the Vitamin D3 (not D2) you need? We’re going to discuss that in a moment, but first I would like to briefly review…

Why Vitamin D Matters For Your Bones

It’s well-documented that Vitamin D is essential for the proper synthesis of calcium, and it’s been shown to greatly reduce fracture risk in two ways. First, it helps with the formation of stronger bones; second, Vitamin D actually helps improve balance and prevent falls by enhancing muscle contraction.

For rejuvenating your bones, it’s vitally important that you avoid Vitamin D2, and choose a bioavailable form of this important vitamin to avoid deficiency.

If you live in an area where it’s difficult to get sun exposure or if you can’t spend 20 to 30 minutes outdoors a few times a week, then you should be taking at a minimum 600 IU of Vitamin D3 or cholecalciferol daily. But to achieve and maintain desirable levels, I recommend taking 2,000 IU once a day. Don’t worry that you may have too much Vitamin D if you also sunbathe. Remember that there’s no risk of overdosing from the sun.

Till next time,


1 Houghton, Lisa A. and Vieth, Reinhold. “The case against ergocalciferol (vitamin D2) as a vitamin supplement.” The American Journal of Clinical Nutrition. October 2006. Vol. 84 no. 4. 694-697. Web.


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Comments on this article are closed.

  1. Chris

    Whatever you do, insist on Rocaltrol (brand name) Vitamin D3. Not Vit D2.

    As pharmacist I knew this when I visited the nurse practitioner (getting to see a Dr is about impossible in today’s health care system.)

    For years my blood work shows substantial Vit D deficiency–even with Rocaltrol (I wanted brand) Vit D3 50,000 units five times a month.

    Well she insisted to order Vit D2 and when I called and called trying to be heard-she discharged me as a patient !!!!!!!

    So—heads up, THE system will push you to Vit D 2. Seems the system wants that. You may now know better. Maybe this article will help you be heard.

    Also this is a video on the subject by Dr.Alexander Wunsch, MD, Wismar University of Applied Sciences, Germany, discusses the importance of measurement when studying vitamin D. Michael F. Holick, PhD MD, Boston University Medical Center, discusses how to treat patients at risk for vitamin D deficiency.

    • Vivian Goldschmidt, MA

      Thank you for sharing, Chris. It’s our aim to inform Savers about the dangers of taking D2 through this article – thanks for adding to the information, we appreciate it.

  2. Sheila

    Just a quick e-mail to let you know that I cannot tolerate D3 (tried oil form, then tried dried form) and therefore have been taking D2 for nearly 20 years. One D3 gives me an upset stomach (diarrhea) which last for days and then I can’t take any of my supplements. Take 50,000 IUs every 6 days and it seems to work for me. No fractures. Hard to believe I’m the only person in the USA (world?) to have this problem.

    • Sabina walsh

      I take food first before I take vitamins. Otherwise I would have dirrach. Hope this helps

  3. Jill

    I have just discovered a product that I think is very worth mentioning. It is NewChapter Bone Strength. Why I am impressed is because it contains D3, K1, K2, calcium, magnesium, strontium, silica, venadium – all made from organic sources and in right proportions. (Originally manufactured in Vermont but recently sold to a large corporation that is keeping intact the original ingredients.) Recommended dose is 3 tablets a day. Not cheap but I’m giving this a try. If one can trust reviewer comments it seems to have greatly improved bone density scans. My highly educated doctor has recommended Fosamax (now being sued) and high doses of D2. Lesson: Always research as best you can whatever drugs and therapies doctors recommend.

  4. michaele alpenglow

    I’m a big fan of drs. Slnatra and mercona re supplements for atherosclerosis and osteoporosis. I have both. Refuse to take oste meds in any form, due to possible necrotic jaw problems, so really want correct info on supplements. Primary Dr has me on 50,000 IU of D2. I want to switch to D3. On my own, I take magnesium, and just started K2 MK7. Take those with calcium 1000-1500( Dr recommended. Take ,also, COQ10 ,etc., per Dr. Sinatra’s booklet. My biggest fear . . .a clot or unstable plaque (have narrowed carotid) from taking K2! ! I’m also on low dose asperin. Please advise. Thanks

  5. Lawanda

    My doc prescribed me vitamins d2 50000iu once a week is that to much

    • Kathleen

      Hi Lawanda, I would get a second opinion from another physician. 50k sounds high and this arrival just revived the better benefits by taking in more sun natural D and that D3 is a better option then D2. Hope this helps. Good luck !

      • lawanda

        thanks i thought that was to much and when i took another blood test it raised my level up one point now i am on over th counter d3 3000 iu a day

  6. Nelda

    After reading so many different points of view on vit. 3 vs. Vit. 2 , I’m more confused about it. I’ve never been told what my vit D level is, and don’t know if it’s ever been tested.

  7. Georgie

    What does the 3 mean in vitamin D, and what is the difference between Straight vitamin D and Vitamin D3 ?

  8. Romila

    Dear Mam

    My Vitamin D level is 14 and i took vita d3 10000 ICu daily for 1 month. Now doctor prescribed d2 50000 per week. Clacium 600 .+D along with this. Is it the correct balance of suppliments. please advise

  9. Kathleen Schleehauf

    ***Please research and share information on the critical partnership of D3+K2*** All my physicians have tried different forms of Vitamin D so that I could absorb it but none worked. Then I tried a D-3&K-2 combo that has raised my levels from 17 to 28. I’m thrilled and I also learned about how important Vitamin K-2 is in combination with D3. Physicians NEVER talk about it! Thank you!!

    • Sandy

      It is correct that you never hear of K2 and this is what makes D3 work. (You might raise your D levels, but it is not “working” in your body without K2.)

      There is an under the tongue (sublingual) dissolving supplement that works very well. The one I use has 1,000 IU of D3 and 90 mcg of K2.

      Do not take more of these if you feel you need more D3 as 90 mcg of the K2 is 112% of the daily requirement and you should not take too much K2. Just supplement with a separate D3 gel cap.

    • Kathleen

      Thanks for info you received from your Dr in regards to D3 k2 combo. Glad your d is doing better.

  10. Françoise Menneboo

    Hypothyroidism since 1978, on 50K X1/wk D2 for 5 years and my OH 25 D level is only 9 (D3) and 30 ((D2) as if Aug 2016. Went through CHF and OPD in Oct 2015. I just found out yeast ersatz from a friend the importance of D3 vs D2, been researching since until I came across your most informative article. I had no idea that Vit D deficiency could lead to CHF and asthma. I am irate that nine if the docs/cardiologists ever mentioned it not changed my Vit regiment. Didn’t even mention my severe deficiency and found out when I demanded copies of my lab results. Now my question is, what level of D 3 should I start with? Thank you for your most appreciated and informative article. Where can I get your book? I’m 64 and live in buttcrack TX where we don’t even have a bookstore. Looking impatiently for your recommendation. I’ve also been suffering from horrible mood swings and brain fog, joint pains and depression.

  11. Galina Rozen

    My Vitamin D-25 Hydroxy is 20.7. My doctor gave me Vit D2 1.25mg(50,000unit) ones per week. Is it correct, or beter to go to Vit D3??? Thank you for answering.

    • Skip

      As a person who was very low on Vitamin D many years ago ( around 20 or a bit below), I was given a script for the 50,000 IU of D2, 1 pill weekly, for 6 months (or 1 years) until my next blood test which came back at 80 (level range is 30-100) and then I went off of it, all the experts say you need to be at least in the 30-50 level range but a little higher is no problem. I also increased my daily multi vitamins from 1 in the am to 2 daily, 1am, 1pm, which is what folks taking multis should take (not the 1 daily the bottle says), and also get a quality supplement that includes Calcium and Vitamin D3, together, never take D alone without Calcium. I have blood tests once a year and I’m in perfect level range on everything every year since, with what I have taken daily for around 7-8 years now, my Vitamin D level is 40-46 (you would think that is low for what I take, but it just shows you how short folks are with D and what you need to do to be in the normal blood level range).

  12. Hillary Rockwell

    Hello, I was diagnosed with MS back in may 2015 and my MS doctor told me to take 4000 iu of D3 daily I been doing this going on 2 years and my MS symptom of vertigo is gone 🙂

    • Fred

      You are right. Vit.D3 is very beneficial and can cure lot of diseases, MS, Lyme, Arthritis, etc. Only Vit. D3 is beneficial, D2 is not good and should be avoided.

    • Nelda

      I have ms, too, and have had it for27 yrs. I was put on a high dosage of vit. D3 the last year..I guess doctors are just learning the importance of it. My biggest problem is pain in my back at the moment. It changes where the pain is.

  13. Marie Lopez

    THANK YOU for the clarification. My lab work said I was deficient in Vitamin D. My DR told me to take Vitamin D 4000IU so I took D3 because that is all I already had. I am healing my thyroid so keeping my liver healthy is very important. Thyroid imbalance depletes vitamin D in the body is what I learned.

    • Vivian Goldschmidt, MA

      You’re welcome, Marie. You are so right about liver health, too, especially as it relates to Vitamin D synthesis.

      • judy

        My lab work said I was deficient in vitamin D my doctor told me to take 2000 mg a day. But didn’t say D2 orD3. I just started taking D3 is this wright. Also I have an underacted thyroid took more blood today waiting to see if he will start me on meds .your input will help me so much thank you

        • Cindy

          Yes! Take the D3. Take liquid also (drops or gels). It will absorb faster, and remember to take magnesium (such as glycinate) and K2 with it. Zinc, A, and E are other cofactors to take with the D3. Boron is also recommended. I’ve never taken the Boron (I’ve had Hashimoto’s for 20 years by the way). My levels were initially around high 40s/low 50s. Within a few months, I had raised it to high 70s with the D3.

  14. JMac

    I was vitamin D deficient & my Rheumatologist put me on 50k on D2. I’ve been on it over a year & went from 15 to 24…..which isn’t much over such a long period. Then it was changed from 1x weekly to 2x’s. But I just found out from my neurologist that I should have been on D3 instead & it is better, especially with absorption. I won’t tell anyone not to trust their doctor, but to just remember they are going off what they know & have learned. New things are discovered everyday. So, at one point they believed D2 was the right thing (not to say it isn’t), but from my symptoms & things I’ve had going on with me, I wish I knew about D3 before because I probably could have avoided some problems. I am now taking D3 2x’s daily.

    • Mr. Brain

      Research and info is fast evolving over Vitamin D so not too surprising. My level was 11 and 12 weeks of D2 at 100,000/week moved it to a 29. Now doing 7,000/day of D3, adding in more calcium and magnesium.

      I have MS and some of the Vitamin info from G.P. was correct and some wasn’t. My neurologist same thing… he had some things right and some not so much.

      Both D2 and D3 do work. Folks on this blog make it like one is junk and the other is a miracle. Doctors typically use D2 as you can err on the high side without dire consequences esp. when giving real high doses. D3 a little more volatile at higher doses. But don’t take my word for it… check my citations… check EVERYONE’S citations…

      Vitamin D Intoxication and Related Hypercalcemia
      Etiology and Effects of Vitamin D Intoxication

      Increased serum 25OHD levels and resulting hypercalcemia are the hallmarks of vitamin D toxicity (Jones, 2008). Although intakes of either vitamin D2 or vitamin D3 can cause toxicity, there is evidence that higher levels of vitamin D2 can be tolerated (Hunt et al., 1972; Stephenson and Peiris, 2009). Similarly, in laboratory animal experiments, vitamin D3 has been reported to be more toxic (Roborgh and de Man, 1960).

      • David F Sander

        Recent tests of vitamin D3 for toxicity reveal that it doesn’t have much toxicity. A research trial gave patients 15,000 IU of vitamin D3 daily for several months and NO side effects were noted. In a compendium of vitamin D3 toxic patients, there were no patients taking under 30,000 IU of vitamin D daily.
        Compared to this, vitamin D2 has only a quarter to a third the activity in the body, it metabolizes vitamin D3 and raises the concentration of amyloid in the brain. People who want to avoid dementia should avoid D2.

  15. Noname

    I’ve been exhausted and run down, my doctor gave me 50,000 units of D2 for once a week and I could notice a huge improvement in energy after taking my weekly dose. You have no right to tell people to disregard doctors orders.

    • Sam

      Thank you Sandra! Why are you (Advertisement) telling people that this is Toxic to them when it is a Prescription form and Doctors medical opinion for their Patient ? Then turning around to sell your product. You might want to re-write your AD to explain in depth that this is strictly your Opinion and not Medical or FDA approved facts before you find yourself in a Lawsuit and lose what little profit Im sure you have gained by this False information. I probably would of purchased this Product up until this point.

      • Wylie

        After being diagnosed as Osteopenic, I’ve been taking Vit D3 for about 15 years. Recent scan showed normal healthy bones. I’m now 72 yrs old, and being a very fast moving person, have tripped and fallen frequently, with no fractures, but torn muscles/tendons. The specialists were all astounded, but when told I was taking D3 daily, they all commented that it was the D3 that prevented fractures. There are multiple studies that recommend NOT to take D2. Please read info from The Vitamin D Council.

  16. Sandra

    Tammy , I take 50,000 twice a week (Mon & Friday) I have took this for years.
    My doctor does blood work every 3 months and I trust him completely

    • Noname

      I agree completely

  17. wanda cruzado

    Hi: I took three month therapy of 25-hydroxy, 10,000 monthly and my vit D levels rise from 21 to 22 only, while my pth gets 95. I live in a tropical island so sun is free and heavy. My doctor told me about the D2 and now I am reading is not safe. What I am suppose to do? Help. the bone pain is getting worst.

    • Sandy

      Mr. Brain is correct in his advice.

      Additionally, you need to take K2 and this is what makes D3 “work” in your body. D2 or D3 will raise your levels, but it does not guarantee it is working in your body.

      I posted the following above:

      It is correct that you never hear of K2 and this is what makes D3 work. (You might raise your D levels, but it is not “working” in your body without K2.)

      There is an under the tongue (sublingual) dissolving supplement that works very well. The one I use has 1,000 IU of D3 and 90 mcg of K2.

      Do not take more of these if you feel you need more D3 as 90 mcg of the K2 is 112% of the daily requirement and you should not take too much K2. Just supplement with a separate D3 gel cap.

    • Mr. Brain

      I agree with Cindy’s comment at least in switching to D3 as you may have other complications that are slowing down the D2. D2 chemically needs to change to D3 and D3 needs calcium, magnesium to really be bio-available to you.

      It sounds like a merry-go-round but you need Vitamin D for one thing… it regulates calcium and magnesium in the body… but you need calcium and magnesium in the body for the D3 (or D2->D3) magic to happen. And it takes a long time to get caught up if you’re that deficient.

      I don’t know if it’s a typo but 10,000 monthly is bupkiss. It took almost three months of 150,000/week for me to go from an 11 to a 29.

    • Cindy

      D2 does not absorb well. Take D3, and make sure you take a good absorbable magnesium (such as glycinate) and K2 with it. Zinc, A, and E should also be taken (Boron is also recommended). I’ve never taken the Boron, but I take the others regularly. Take a gel or drop D3 also. It will absorb faster.

  18. Johnny N.

    I am 74 years old. After reading this article I am very much confused. My doctor prescribe Vitamin D2 50,000 IU and one capsule every 2 weeks. I just bought a bottle of Vitamin D3 5,000 IU (300 softgels) from Costco this morning.
    My question is should I use it along with the 50,000 unit that I am taking every two weeks, or do I have to wait until I ran out all the D2 prescribe by my doctor? which one is better for me?

    • Joan

      I too was on an elevated dosage. Finish the doctor recommend amount first. That amount is to bring u your level. Then take the D3 you bought.

  19. Lamar

    I have D deficiency. My doctor proscribed VIT D 50,000 IU D2 (ERGO) CAPS for me. I took one capsule yesterday afternoon after I got my prescription. I have been having terrible headache for over a day now. I just realized my headache is caused by the D2 capsule I took. It can be toxic for certain people!!

    • Vivian Goldschmidt, MA

      Thankfully you discovered the problem before taking any more, Lamar! I hope you’re able to get your Vitamin D levels up safely.

  20. Ron Mak

    I’m new here and loved your comments. I was also told my D levels are dangerously low. Here’s my dilemma. My primary Dr prescribed me D2 25,000 once a week. But me Rheumatologist said D3 5,000 a day. I don’t know if I should take both or just stick to D3. Would appreciate any advice.

    • Sandy

      Posted above but hope you see this:

      It is correct that you never hear of K2 and this is what makes D3 work. (You might raise your D levels, but it is not “working” in your body without K2.)

      There is an under the tongue (sublingual) dissolving supplement that works very well. The one I use has 1,000 IU of D3 and 90 mcg of K2.

      Do not take more of these if you feel you need more D3 as 90 mcg of the K2 is 112% of the daily requirement and you should not take too much K2. Just supplement with a separate D3 gel cap.

    • Anna

      New study shows that we need vitamin k2mk7 taken with vitamin d3.otherwise the d3 is not distributed where it needs to go to the bones instead goes in the arteries

      • Diana

        I just read, on the Mayo Clinic site, about all the side affects of vitamin D. I was appalled. One of the side affects was hardening of the arteries. Something is wrong if a vitamin is so dangerous. Here it is…
        Vitamin D may cause allergic skin reactions (inflammation, irritation, rash, and thinning), build-up of calcium in the arteries, changes in cholesterol levels, daytime sleepiness, excessive vitamin D levels, hardening of the arteries, headaches, increased calcium excretion or levels, increased risk of falls and fractures, increased risk of heart attack and stroke, increased risk of high blood pressure during pregnancy, increased risk of urinary tract infection, kidney or urinary stones, muscle pain, respiratory tract infection, and stomach problems (constipation, cramps, diarrhea, upset stomach, and vomiting).

        Vitamin D may affect blood sugar levels. Caution is advised in people with diabetes or low blood sugar, and in those taking drugs, herbs, or supplements that affect blood sugar. Blood sugar levels may need to be monitored by a qualified healthcare professional, including a pharmacist, and medication adjustments may be necessary.

        Vitamin D may affect blood pressure. Caution is advised in people with blood pressure disorders or those taking drugs or herbs and supplements that affect blood pressure.

        Use cautiously in people with headaches, heart disease, immune disorders (including lymph cancer and tuberculosis), kidney disease, liver disease, lung disorders, musculoskeletal disorders, skin disorders, stomach disorders, and thyroid disorders.

        Use cautiously in pregnant women at risk of high blood pressure associated with pregnancy.

        Use cautiously in breastfeeding women.

  21. Vicky

    How can I know the level of both D2 and D3 in my body?
    My doctor prescribed me to take Vit D. It was difficult to get my test data and to know what kind ofVit D. It looks like nor the clinic neither the doctor wanted to give me me details. I had to mention my legal rights. Even though I could only take the info after approaching the doctor in the lunch room 3 hours later. The test just says Vit D. My doctor said D2 act faster and my plan does not include D3. My plan neither include D2. So what is the issue? Money.???
    Before taking D2 I decided searching on professional scientific investigation and history about D2 and D3. After some searching I concluded D3 is better than D2 and I will take it over the counter. I also conclude Big Farma is behind this and other health issue. I will continue searching on this and other info from my test. Of course, I will search about Big Farma. Looks like they are killing people to get money.

    • Vivian Goldschmidt, MA

      Hi Vicky,

      It sure sounds like you’ve had a frustrating experience!

      The most accurate way to test for Vitamin D is a 25-hydroxy-vitamin D [25(OH)D] blood test. Levels above 50 ng/ml are considered fine. Unfortunately, about 10–20% of the doctors order the wrong test. They order a 1,25-dihydroxy-vitamin D, thinking that by measuring the most potent steroid in the system, they are getting useful information. They are not. 1,25-dihydroxy-vitamin D is an adaptive hormone; it goes up and down with calcium intake. Furthermore, as 25(OH)D is a weak steroid, when 25(OH)D levels are low, the body compensates by increasing the amount of the potent steroid, 1,25-dihydroxy-vitamin D. Thus, a common cause of high 1,25-dihydroxy-vitamin D is low 25(OH)D or vitamin D deficiency.

      The bottom line is that you should first be sure that your vitamin D deficiency was accurately measured, and then, if your levels are confirmed low, decide how you want to proceed.

  22. Chris V.

    This is scary… I have been researching Vitamins for over 30 years. In that time, I have never heard of “Not being able to overdose from the Sun…”. Nor have I heard that D2 was inferior to D3. especially since D2 is the naturally occuring form of Vitamin D that is found in Fish and other plant based oils.
    The reason that there is a warning label on D2 “INJECTIONS” and “50K” prescribed dosages is because the body is NOT supposed to break it down quickly. The body is designed to break down D2 over a 24-48 hour time frame; whereas D3 is broken down within a 4-6 hour timeframe and whatever is not used by the body is flushed out of your systems via natural filtration (your kidneys).
    Now, D3 is readily available on the market and can be taken in large enough quantities to ensure that your Vitamin D2 concentration Serum levels are, when checked by a lab, within normal ranges. It is also much cheaper than it’s D2 cousin. However, Please understand that this article is designed to scare you into believing that one form is inferior to another, which is simply not the case. D2 is simply not as readily availble as D3. That being said, Each Has its benefits and its drawbacks. Do yourself a favor, Research vitamins on a respectable site, not the first one that Google throws up at you.

    • Wylie

      Chris, not true, D2 is not natural, D3 is. Please check before writing ….

      • Cindy


    • Lisa

      Thanks Chris,
      Your comment really helped and it also re-enforced other articles I’ve read on Vitamin D2 and Vitamin D3. Reading this article scared the crap out of me. After reading a little further I see now the website is trying to push a product.
      Just Sad

    • Tammy

      Thanks Chris!!! My mom has osteoporosis, she has to take the D2 50K once a month, the doc told her it was different than that of the sun and take it exactly as prescribed…. hence the google search!!! I just had to find out the difference…. for me, your comment was VERY helpful…

      • Sandra

        Tammy I take 50,00 un twice a week, Monday & Friday. Have for several years
        My Doctor does blood work every 3 months and I trust him completely

    • Vitamin D

      I would not follow the advice of a person who is not medically qualified, but I do like to read what other people have personally experienced. You had stated “whatever is not used by the body is flushed out of your systems via natural filtration (your kidneys)”. In my experience Vitamin D can NOT be flushed out of your system. I had neck surgery and was put on 50,000 units of D2 once a week. Approximately 10 months later after a routine blood work, it show my Vitamin D level extremely high at 64, normal is greater than 30. If vitamin D was able to be flushed out of your system I never would have gotten this high.

      Long-term complications of untreated hypervitaminosis D include: kidney stones, kidney damage, kidney failure, excess bone loss, calcification (hardening) or arteries and soft tissues

      I do need to research why taking just 1,000 units a day I can’t not absorb the Vitamkn D, as a result I have hyperparathyroidism.
      PTH-N-TACT 112.6 High pg/mL 11.1-79.5

      • Chrisy

        Who told you it was extremely high at 64? Optimal levels is 24.0-80.0np/ml. Theraputic, cancer fighting range is between 70np/mm and 100np/mm. Also you need K2MK7 in order for your body to absorb the Vit D. People taking Calcium with Vit D are more prone to heart attacks and the problems you speak of. I have been researching these things since I found out my Vit D2 is <4.0np/ml and my D3 is 12.4np/ml which is severely defficient.

      • Anna

        You need k2mk7 for the vit d to be absorbed

    • Chris V.

      Lost my train of thought sorry:
      Regarding the warning label–because the body breaks down D2 over a 24-48 hour period, the half life of D2 is 60 hours (5 days), you only take the large dose (usualy 50K IU) once a week. taking it any sooner would result in a build up and cause a strain on both your Liver and your kidneys as they try to process out the excess. This can lead to both liver damage, kidney stones, kidney failure, and other NASTY issues.
      Bottom line. If you are taking D2, take it as prescribed if it is in a High Dose–ANYTHING OVER 5000 IU is considered a HIGH DOSE of D2 or Ergocalciferol (if reading it on a vitamin lablel.
      The RDA for D3 is 600 IU max daily.
      The RDA for D2 is 350 IUmax daily

      • Chrisy

        Who told you it was extremely high at 64? Optimal levels is 24.0-80.0np/ml. Theraputic, cancer fighting range is between 70np/mm and 100np/mm. Also you need K2MK7 in order for your body to absorb the Vit D. People taking Calcium with Vit D are more prone to heart attacks and the problems you speak of. I have been researching these things since I found out my Vit D2 is <4.0np/ml and my D3 is 12.4np/ml which is severely defficient.

      • Dawn

        I had my thyroid removed bc of cancer 3 1/2 months ago. Dr put me on vit D2 50,000u weekly. After reading your blog, got me thinking is this to much and do I really need it?I don’t need kidney problems too.

        • Tammy

          Please discuss this with your doctor, get him to go over your level with you, and discuss any thing else you might be wondering about. With things like this, you shouldn’t just wing it…. at least not without discussing it with you doctor… 🙂

  23. Laine

    How can you state “Remember that there’s no risk of overdosing from the sun.”?

    We are ambushed daily about how harmful it is and in that one sentence you have destroyed your credibility.

    • Diana

      The article said you can’t overdose on vitamin D from the sun. It wasn’t talking about sun damage. On other words, you can stay in the sun as long as you want and not get too much vitamin D

    • ahna

      Clarification : The author of this article was implying not being able to overdose from vitamin D from the sun not other risk factors of excess sun exposure ; cancer etc…

  24. Alex

    I have a low Vitamin D count and i always knew i did but decided to go see a doctor about it and he prescribed D2 50k once a week, i havent taken it yet.

    I told my doctor i had low energy levels, low sex drive/libido. He did bloodwork he said my testosterone levels were normal but on a recent trip to Miami in April i laid out in the Sun for about 20 min and about 4 days later i experienced this little bone pain like when you have a flu. Sure enough my testes got fuller/larger, my penis hung, was thicker fuller and my sex drive went up, its amazing what sun can do for you. The sun definately recharges your manhood. Problem is, it didnt last for long, so there is something about sub tropical climates and being closer to equator that it does something for you, i had same experience when i flew to central and south america, call me crazy but my sex drive hits normal levels in tropic areas and gets low when i get back home, hmmm strange but true.

    • mykul johnson

      I live in MI. In July and August (our hottest months)… testicles feel bigger…scrotum hangs lower…penis hangs little longer and appears slightly thicker as well. When I am in constant warm climate….everything hangs lower and increase in libido. It’s simply what was called “the shrinkage factor” on the Seifeld show.

  25. Charles Bettacourt

    This article is DANGEROUS. If you have chronic kidney disease, renal insufficiency, or are in renal failure, following the advice of this non-medical writer would be, at the least, very foolish, and at the worst, deadly. I can’t believe such misinformation is legal when it comes to medical “advice”. This writer is free to write whatever she thinks she knows about, even when she’s wrong. Just remember that.

    • Red head

      Look it up and Google the difference. ARE U KIDDING ME??? D2 is a manufactored substance. NOT D3. My father who know has ONE kidney takes 3 along with K2. And his DR told him to.

      Research first before you make your foolish comments

  26. hope

    hi ive taken d3 and i can swear it immediatly weaken my kidneys but when i take d2 it doesent and strenthings my musles and i feel better truth is d3 is more toxic than d2 because d3 is uptaked to fast in the body than d2 .d2 is change by the system by what it needs body decides but d3 its allready changed body dosent decide but tries to use whats to much to availible same thing with vitamin e verses sytenthic to non sytenthic interestely vitamin k3 was damaging peoples kidneys but not k2 which all oils are in the same family please be careful with vitamin A also very dangerous also the fact is to much carrot juice can kill you so to much of any natural form is bad to but taken right is less toxic than a sytethic form in a lower dose so stict with d2 but dont take high doses dont take d3 bad like vitamin k3 take care follow physians orders.

  27. Lindsey

    I just had blood work done and my vitamin D2 level is 4ng (severely deficient), and my D3 levels are 16ng (deficient). I’ve also heard D2 supplements are not good to take, but I’m having a hard time finding how to raise D2 levels. I just found out a few days ago, and have been sitting out in the sun without sunscreen for about 30 mins each day, but I want to understand more before I go back to the doctor to discuss what’s next.

    Every single article I’ve read talks about low vitamin D levels, but no one ever talks about what their actual levels of each are. If my D2 is severely deficient, I’m not seeing anyone talk about how you address that. Any advice would be greatly appreciated.

    • Diamond

      I can understand where you’re coming from I just had blood work done and my levels are 10.5 I was prescribed vitamin D2 and I’ve heard really bad articles on it at this point I’m not even sure of what I should do I go talk to my doctor on the 24th of this month to get a better understanding of which one is safer to take because right now I’m so confused some people say take Vit D2 and some say take Vit D3 all I want at this point is to know how Vit D2 helped people not how bad it is or not

      • Hayley

        I’ve had low vitamin D levels for years now. I’ve been put on the high doses for usually 6 weeks but they never re-check my blood levels to see if they are good. This time I had it checked at a different Dr’s Office. I was low at 27. According to their ranges under 30 is low. So they put me on 50,000 for 6 weeks. I have had eczema on my arms for the last few years that won’t go away (even with steroid creams), I have never had eczema in the past. After two weeks of taking it I started noticing that after a day or two the eczema would clear up like it was never there, but a few days before I needed to take the D2 again it would come back. My daughter has had severe eczema her entire life so I took her into be checked for Vitamin D. She was even lower than me at a range of 22. They put her on the same 50,000 D2 as me. 6 weeks later we both went in to be checked. My daughter’s went up to a range of 38, mine went down to 11! I don’t understand it and neither did the doctor. The doctor told me the D2 and D3 is suppose to be the same but since my levels went down she is trying me on 50,000 D3 for 6 weeks. I don’t think one is necessarily worse than the other I just think that everyone’s body reacts differently to everything.

    • Alex B

      So you’re worrying about specific Ds without thinking about what you’re putting into your body via sunscreen…. (which can negate any benefit you may get from the sun).

      Try coconut oil…

      The skin breathes and absorbs, remember that.

  28. Jaziel

    This lady, Dr Rhonda Patrick has a lot of Interesting health findings.

    This is a graphic about vitamin D

    • Alex B

      The name Jaziel plus talking about Phd.

      I find it hard to believe your comment is sincere and not basd on selling a product.

      Names matter.
      signed ENTP.

  29. Kris

    Bad advice to say that you cannot overdose on vitamin D produced by sunlight. Whenever I have prolonged sun exposure (a day out fishing for example) I get elevated vit D levels and toxicity results. My grandmother was the same. I’m sure there is a gene affecting the feedback mechanism that moderates vit D production and we are not the only ones affected as I have heard similar stories from others. I have to be very careful with vit D supplements and sun exposure.

    • Jim

      Kris, you are too quick to comment on D2 vs D3. Do a little Google research on
      D2 vs D3. I think you will change your mind. As you said you react much differently to sun exposure than others probably due to a genetic situation. But for those
      without your condition I would guess that 99.99% of the population needs the extra Vit D3 or exposure to Sunshine if they don’t live in the tropics or the desert.

  30. Laurie

    There is no merit to this article. I live in the north where I get D3 from the sun for only 3 to 4 months out of the year. The rest of the year I take D2. I am 47 and 100% healthy vegan. So is my 66 year old mother, my fiance and my 23 year old son. We go for yearly physicals and are tested every year and we are always healthy. Is Vivian, the author, a nutritionist and a registered dietitian? That is the first question to be answered here.

    • Jan

      D 2 is the worst form of vitamin D you can take. This is a very excellent article and it most definitely has a great deal of merit. Remember, everyone is different. I would not take D 2 if you handed me a million tax free dollars. The same goes with the inferior poison brands of 12 Methyl B 12 is the best and the safest.

      Glad you are all healthy though!

  31. Maria

    Hi, I was diagnosed with osteopenia and I take Alendronate 70mg once a week. I have beeb taking this for a few years now. What do you think? Is my doctor prescribing the right meds for me?

    Thank you.

  32. E Nesland

    I am studying to be a nurse practitioner- have worked in pediatrics for 20 years- and I’ve never seen a licensed health care provider prescriber supplementing for vitamin D deficiency with ONLY vit D3, they always give ergocalciferol as well. (When blood levels become adequate we continue only the D3) I can’t find any basis for this!! Not even USPSTF guidelines!! Why? All I can find is this in a Medscape article which echoes your assertion:
    “Traditionally, oral formulations of vitamin D2 and D3 have long been regarded as equivalent in their clinical activity. However, studies indicate that ergocalciferol (vitamin D2) is much less potent and has a shorter duration of action than cholecalciferol ” Is it simply old habits die hard?

    • Kevin

      D2 perhaps less “potent” (whatever that means) and shorter “duration” (whatever that means) may well be true but the terms are a bit vague. D2 is in your system for more time (has a longer half life) and is not as immediately bio-available as D3.

      Hard to find consistent info on Vitamin D via Google but I found this link to be helpful… which is the “DRI DIETARY REFERENCE INTAKES Calcium Vitamin D”. Some good reading if you’re into the obscure and have a bad case of insomnia (1,114 page long…. yikes!).

      And yeah, I agree… I think a lot of this IS due to fact that old habits die hard. I think that the thinking was in “The Old Days” was that if you got a patient to take D2 once or twice a week you didn’t have to worry about daily patient compliance. It would stay in your system quite a while… about 15 days vs 15 hours.

      Hope that helps.

    • Jackie Hildebrandt

      I take 50,000 Vit D 2 once a week. My level is 25, and should be like (30 to 70 ) I have took it for over 7 months. Its seem like a lot to take. My vit d was 11 , when I started taking it How long should I take it ?I worry I am taking too much. Thanks

    • Amy

      I was just diagnosed with vitamin D deficiency and my doctor prescribed me ONLY D2 and never mentioned D3. The pharmacist actually pointed it out to me and suggested I buy D3 as well as my script for D2 and to research it myself before I take either. He recommended D3. I guess it’s hard for doctors to stay current on everything. I’m going D3.

      • Jan

        Amy! Most doctors don’t have a clue. Stick with a good brand of the D 3 and make sure there is no garbage in it like gluten, soy, wheat, nuts ext….

      • katie

        i was prescribed D2 50000mg once a week and it did nothing for my levels so he bumped me up to D3 50000mg weekly to see if that changes anything at my next visit… they were not prescribed together and he hardly mentioned the change in the vitamin if i wasn’t listening closely i would have missed it. This is one of the best doctors in Boston who also happens to teach at Harvard.

        • AnkeS

          D3 is most likely not covered by insurance and D2 is covered. I ran into that b efore when my doc specifically order D3 and I got D2. I refuse to take D2. end of story.

          only D3

          • Cindy

            You can buy a $13 bottle of Carlson’s liquid D3 drops at 4,000 i.u. per drop.

          • Max

            Even though vitamin D2 is covered by insurance, my 50000 mg, once weekly, prescription copay is $20 per month. $220 per year, $5.00 per capsule. While the vitamin D3 10,000mg, free of all those additives I don’t want, taking 5/10,000 per week is just $16.00 for 100 capsules a 5 month supply. Annual cost for D3 is just under $40. I have been taking D2 prescription 50,000 weekly for 2 years and I am borderline deficient. I will be switching to D3 in January 2017 at my next annual checkup. Will do that for a year and then report back what the change is in my bloodwork.

  33. Esther Kusi

    Am suffering from Lumbar spondylosis after delivery, can I take the Vitamin D3

  34. Stephenie

    My doctor put me on vitamin D2 50,000 units twice a week. I had a level of 11 the first time I was tested. Now I’m at a vitamin D level of 18. The highest level my vitamin d has ever been was a 24. That month I took my vitamin as always but I had spent two weeks at the beach. I’ve been on this dose for about three years now. Would it be better to take vitamin D3 50,000 units once a week?

    • Bob

      Particulars from most recent blood panel: 70 years old

      Vitamin d – 36
      Vitamin d2 – 1.4

      • Bob

        Inadvertently hit the wrong button: To continue:

        Vitamin d3 – 35

        What do these figures mean and any suggestions…. Thanks… Bob

  35. Nico

    Hello, this is an old post but my doctor gave ergocalciferol when I was 14 because a medicine for allergy did some bad thing to my bones (sorry I don´t know the right word in english) so this way I recovered and 15 years later I keep an active life, do sports so I hope taken 2 or 3 times when I was a teenager was bad 🙁

  36. Ella willis

    i have a bone problem i am taking alga cal and
    stronitum also doctor prescribe vit d (ergo)50,000 iu ca pliva don know what tis lettering mean 2xa week
    now brand vit d from healthstore 1,00iu vcaps also calcium citrate witj magnesium and vit d 600mg
    cant take another bone test that the insurence wil help with till next year it is expensive to pay out pocket
    i am confused about D3 can the doctor prescibe
    if so i will ask and see if insurance wil pay confusedt
    thanks Ella

    • liz

      you can buy vit d3 at any drug store or grocery store it is inexpensive and it’s over the counter

  37. Sam kasem

    Do you recommend specific vitamin D and calcium , that you know it is the best in the market

    • Ana simon

      I have a compressed vertebra fracture and the doctor just prescribed for me to take 50000 units of vitamin D2. I just read that this is not the best source of vitamin D and the dosis is so high. Really concerned

      • Mr. Brain

        50,000 to 100,000 IU/week is pretty typical for D3. I think the smallest dosage pill you can get is 50,000 IU

        And it’s not that D2 is better or worse. You’re body uses and needs both (and YES both D2 and D3 are “natural”)

        D2 stays in your system for days and D3 is hours. Doctors often prescribe D2 as it converts to D3 over time so it’s like making the vitamin become “time released” HOWEVER…

        Some people have problems converting D2 to D3. As long as you remember to take your pill every day, you’ll find D3 is much more bio-available.

        I have a deficiency and am taking 20,000 IU per day… PER DAY of D3. I was very low… an 11 so keep that in mind. The average person should be fine with 5,000 to 10,000/day.

        According the NIH website, anything below 10K a day is considered safe for the general adult population.

  38. Susan

    Vivien. I’ve been taking True Osteo for bone health but I’ve had trouble with kidney stones and the doctor wants me to take calcium nitrate since my calcium levels are still high. Do you offer that supplement, and can that be taken in conjunction with the True Osteo? Thanks so much.

    • Sheila K

      Please have your parathyroid checked. Kidney stones and high calcium levels are 2 of the main symptoms, along with sweats, fatigue, depression and memory loss…just to name a few!
      Dont do like I did and wait 12 years…tell them to check your PTH levels. I would advise you to go to the best endocronologist in town. Youre on to something with the whole Vitamin D thing but keep digging deeper, my friend- 🙂

    • Susan

      That’s calcium citrate. Stupid spell check

  39. rosemary

    When I take D3, I also take K2 with it. High doses of D3 could also be a problem with sticking to our arteries, and the K2 supposedly helps to keep that from happening. Then another nutritionist says to take magnesium with it also so the D gets absorbed where we want it to go.

    Direct sunlight should only be for 14 minutes. Our cells begin to break down at the 15 minute count.

  40. Lucy

    My primary care physician does recommend vitamin D3. I had my latest bone density test yesterday and my spine and one hip numbers have improved and the other hip has not changed. It seems that I am doing reasonably well thanks to your great information. Thank you, as always!

    • Loren

      How much D3 should I take, how often, how long? I Get outside a moderate amount (sunny So Calif). The dr. Did think my levels were low enough that she RX’d 50K 1x/wk for a month.

      • Mr. Brain

        That sounds like a very reasonable number. Unless covered by insurance, D3 can be taken daily. I just got bottle of 5000 IU D3, 360 pills for under $10 at That’s a full year for less than $10… can’t beat it.

        And that’s a dose that you can (and should) take for the rest of your life.

  41. bea mowry

    vivian i had a test it was by my heal and it said my t-score is -1.6 is this a bad score thank you bea

  42. Jan D

    Hi Betty, your post is interesting to me because I too have a lot of trouble keeping my weight up (I am underweight as it is) and so cannot keep following the 80-20 ratio. Of course doing exercise uses up more calories as well.
    Thanks for your reply to the post Vivian, I have hesitated about including more pasta as it is acid forming, but recently found buckwheat and millet pasta (alkalising grains) and so am eating more of that. I am also trying to making healthy but higher calorie snacks using predominantly alkalising ingredients (almond & coconut flour, buckwheat and millet, coconut butter for eg). I know we are in the minority trying to keep our weight up and I know that being underweight is bad for bones so it is a bit worrying at times. If you have any tips I would be pleased to hear them, thanks.

    • Connie

      Stop eating dairy! The protein in any dairy product draws calcium out of the bones. Yes, dairy contains calcium, but the net effect is a loss of calcium to your bones. It is unhealthy to eat dairy. No doubt the powerful marketing promotion of
      The Dairy Association has most people deceived and this information probably sounds incredible. But check out to see the amazing amount of research that supports omitting dairy from the diet.

      • Mr. Brain

        A more CREDIBLE citation needed on that one, Connie. If you google the author of “The Milk Letter”, Robert M. Kradjian, MD you’ll see the only links to this guy is the THIS letter that he writes and… “The Milk Letter”.

        A letter that has ZERO citations other than mentioning which is a website dedicated to no GMO’s, the Earth is burning up due to global warming, etc. Their own “About…” page describes their web site as such…
        “Utne Reader is a digest of the new ideas and fresh perspectives percolating in arts, culture, politics, and spirituality.”

        I’ll trust Harvard over UTNE any day.

        Read this article from T.H. Chan from Harvard University talking specifically about milk as a source of calcium.

    • Haris

      im suffering from osteoporosis, im 26 years of age
      please i need your expert opinion about it

    • Vivian Goldschmidt, MA

      Glad to know you’re proactive about your bone-healthy diet and caloric intake. Some of us are prone to lose weight easily, so I completely understand. And I think you’ll enjoy reading this previous post on how weight affects your bones:

  43. Ita.

    Thank you, Ita.

    • Vivian Goldschmidt, MA

      You’re very welcome, Ita. Love having you in the community!

  44. Betty

    Have not been in the conversation for awhile due to being busy and sometimes not feeling well. Vit. D3 is the one that is promoted here for bone health. I take 2000 iu every day and probably should do more. Just had a bone density test in March. Showed my spine had a slight improvement from -4.3 to -4.2 (+.17 per cent) but the hip was down from -2.8 to -3.0 (-4.25 percent). Why the difference I wonder. My category of risk is severe. My exercise of squats and walking etc should help the hip. I can’t follow the 80/20 target for nutrition as I need to maintain my weight which has always been hard for me to do. I want to tell you how much I appreciate the resources that are sent to us on a regular basis. What a wealth of information. My mind doesn’t retain all of it but easy to reference when we need to check out info about the drugs being used for osteop. etc.

    • Vivian Goldschmidt, MA

      Hi Betty,
      Don’t let the numbers worry you! Remember, the numbers do not show bone quality, and if you’ve been following the Program, chances are your bones are in excellent shape. If weight maintenance is an issue, consider choosing high-calorie options for your 20%, such as beef instead of turkey. And you can also add more carbs to your 20%, such as pasta. And it’s fine if you need to do more of a 70/30 ratio. 🙂 Keep up the great work!

      • Betty

        Thanks for your encouragement Vivian. I try to remind myself of that. I actually had a bone density technician say that once – that our bones are more than just the numbers. I think the term is tensile or maybe flexible is better.

        • Vivian Goldschmidt, MA

          Yes, exactly! Bones that have been exposed to osteoporosis drugs may actually be “denser,” but they are harder and thicker and more prone to breakage (think of a thick, dry stick vs. a thin, flexible twig).

  45. Caroline

    Vivian, first thank you so much for your work on behalf of the rest of us who are seeking healthy answers to our questions about health. I have received your emails for at least two years and have learned a lot. I love True Osteo which among other things helps me to get a good night’s sleep.

    I tried to order the probiotic supplement you suggested, then was going to add TrueOsteo to the order but was unable to do so. I understood from your website that I could order both from the same place. Perhaps I don’t have the appropriate link? Can you help?

    • Customer Support

      Hi Caroline,
      If you want to order both items together, your best bet is to contact NatureCity directly. You can do so at this link.

  46. Georgiann

    Hello Vivian – Can you please comment on why you do or do not recommend calcium supplements? Thank you so much for your very helpful information.

  47. Belinda Svatek

    Can you improve negative two diagnosis. Severe pain mostly on left side of body! Cannot take drugs that are available, had serious side affects while taking them. Statins sideffects unimanaga me pain. Now they have perscribed Prolia, no way am I going to take that. Help!!

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