Doctor's Note

This is the third video in a nine-part series on vitamin D. Be sure to check out yesterday’s video: Evolutionary Argument for Optimal Vitamin D Level.

For more context, check out my associated blog posts: Vitamin D: Shedding some light on the new recommendationsAçai to Zucchini: antioxidant food rankingsEating To Extend Our Lifespan; and Vitamin D from Mushrooms, Sun, or Supplements?.

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  • Michael Greger M.D.

    Please feel free to post any ask-the-doctor type questions here in the comments section and I’d be happy to try to answer them. This is the third video in a nine day series on vitamin D. Be sure to check out yesterday’s video-of-the-day Evolutionary argument for optimal vitamin D level.

  • Veguyan

    Looks like taking individual vitamins is not so healthy. I hope taking vitamin B 12 is safe.

    • DrDons

      Hi Veguyan, Yes it appears that taking isolated vitamin supplements is harmful especially in the case of the fat soluble vitamins A & E. Isolated supplement of betacarotene has also been shown to be associated with bad outcomes. Supplemental taking of B vitamins has not shown to be harmful or helpful for otherwise healthy folks. Dr.Greger’s video can provide more information. His recent videos on Vit D help shed light on the newest “craze” of supplementation. Vitamin D is a fat soluble vitamin and is known to be toxic in higher doses. You can supplement Dr. Gregers excellent information by reading an article by Dr. John McDougall in his March 2011 newsletter entitled, Vitamin D: Values for Normal are Exaggerated. The supplement you need to make sure you take is Vitamin B12. See Dr.Gregers video, This can be done by weekly, daily or consuming adequate amounts of B12 supplemental food. The easiest one for me is to take a sub-lingual 2000 mcg tablet as Dr. Greger recommends. So the best way to get your vitamins, minerals and nutrients is eating a whole foods varied plant diet.

  • Getting these vitamins from whole foods and your D from the sun seems like the best way.

  • So What’s the conclusion? Is sunshine enough? Is a small amount of supplementation necessary? How much Vit D should I be taking daily, if any?

    • Michael Greger M.D.

      Great questions–I answer them all in the 6 video conclusion of my video series on vitamin D. Click on the “Next Up” video in the upper right hand corner of this page to go to the subsequent video.

      • kamojett

        There is no “Next Up” if you are watching this on the page. ….Just sayin.

    • James Kantor

      If you can get in the sunshine for 20 min a day. Then otherwise that wound be enough. I have been taking 2,500 IU for serveral year.
      You can and should get a blood test for Vitiman D, then you will know for sure.

  • Michael Greger M.D.

    For some context, please check out my associated blog post Vitamin D: Shedding Some Light on the New Recommendations!

  • Ronald Chavin

    The following supplements are now known to be harmful except in special situations: vitamin A (retinol), beta carotene, vitamin B6 (pyridoxine), vitamin B9 (folic acid), vitamin E (alpha-tocopherol), acetyl-L-carnitine (triggers TMAO), and the pro-oxidant minerals iron, copper, manganese, and aluminum.
    The following supplements are usually only slightly beneficial: vitamin C (increases blood glutathione by 50% but increases heme iron absorption), calcium (causes calcified arteries), selenium (very beneficial antioxidant in theory but little or no benefit in practice), vitamin K1 (no benefit to bone health as had been hoped but surprisingly prevents cancer), astaxanthin (most powerful carotenoid antioxidant performed not quite as wonderful as expected), and fucoxanthin (works well in animals but may not work in humans)
    The following supplements have been shown to be extremely beneficial: vitamin B12 (even meat eaters should swallow vitamin B12 pills to prevent brain shrinkage), vitamin D2 or vitamin D3 (aim for 24ng/mL to 34ng/mL, which is the same as 60nmol/L to 85 nmol/L), vitamin K2/MK-7 (removes calcium from calcified arteries and puts calcium into bones to effectively prevent future bone fractures), tocotrienols (powerful fat-soluble antioxidants), vitamin PQQ, nattokinase (melts away blood clots), long-chain omega-3s (from krill oil, fish oil, or algae), conjugated linoleic acid, forskolin, astragalus, Korean red ginseng, psyllium husk, amalaki, triphala, zinc, benfotiamine, alpha-lipoic acid, and probiotics (lactobacilli, bifidobacteria, and bacillus subtilis natto).

  • Kartoffelmao

    First of all, several studies showing harm from taking vitamins use synthetic (isolated out from a spectrum) or a form of the vitamin that is not even found in food! Why is this not talked about??? We cant just assume folic acid is harmful just because a form that is not even found in food, has studies showing it is carcinogenic. This is beyond stupid if you ask me and shows a lack of IQ.

  • baggman744

    OK gang, I welcome your opinions: Of course I realize he SELLS vitamin supplements.

  • Shaylen Snarski

    You need to supplement with vitamin D if you’re not getting adequate sun, but you can do so by taking whole foods supplements. I take a supplement in the winter made 100% from organic mushrooms, so basically to say that THAT particular whole foods supplement would be bad, would be like saying that eating a bunch of organic mushrooms would be bad. Supplementing with concentrations of 100% whole plant foods is very different than unnatural supplements meant to replace foods. Some people can’t afford to eat all the foods they need to get optimal nutrition. I think it’s important to look at the difference between natural whole foods supplements and artificial supplements instead of scaring people out of taking something they may need, like vitamins D during winter months in an area where people are deficient that time of year. I don’t like videos like these because they don’t address the differences. But I don’t think there’s studies done on natural, whole foods supplements. Regardless, common sense says if it’s a bunch of concentrated fruit and veggies making up said supplement, then it’s food… just in concentrated form.

    • Rebecca

      Hi Shaylen, I feel similarly. What supplement brand do you take? And is it D2 or D3?

      • Great question Rebecca! I am a volunteer moderator that helps Dr. Greger and hopefully can provide you with some additional information. D2 is the version of vitamin D known as ergocalciferol. It is less stable and more toxin when taken in larger doses than D3, or cholecalciferol. Both of these are synthetic versions of the vitamin, not a whole food source (unless it states it on the bottle). Always read the labels of the supplement.

        • Rebecca

          The supplement I take currently is D3, sourced from lichen. Still would be curious to know what species of lichen it is!

  • Rebecca

    I would rather consume Vitamin D in whole food form. I noticed my supplement D3 spray contains lichen, but it doesn’t say which species. I couldn’t find any nutritional info for specific lichen species online, either. Native Americans in my region consumed Usnea spp and others — up to 25 lbs/year! Could this have been their source of D, particularly in the winter? I’d like to know which lichen species to harvest, how much would be a serving size of D3, and how to prepare the lichen (soaking/rinsing, cooking, etc.). Any information in the scientific literature that you can find?

    • Rebecca, The amounts available from food sources are far less than that necessary to raise the average low levels, we find clinically. I would suggest that you consider another brand if you’re questioning the excipients. There is a long and well done observational study by Life Extension foundation regarding their lab and supplement findings that clearly make a few points. One is that many people run a low level of vitamin D and that taking it with a fatty meal is absolutely necessary for absorption. Dr. Alan Kadish NF moderator

      • Rebecca

        O.K., thanks, Alan. I just hope that someday Vitamin D supplements won’t be the new Vitamin E, or we’ll have to figure out a more natural way of obtaining it.