Zinc Supplements: Which are Absorbed Best?

Summary

Zinc citrate and zinc gluconate are absorbed well by apparently healthy people. Some apparently healthy people cannot absorb zinc oxide.

A 2014 study from Switzerland compared the absorption from various forms of zinc supplements (1). Measuring zinc absorption in 15 healthy volunteers, they found the following median absorption rates:

zinc citrate – 61% (range: 57–71)
zinc gluconate – 61% (range: 51–72)
zinc oxide – 50% (range: 41–58)

The lower absorption from zinc oxide was almost entirely due to three participants who absorbed much lower amounts, with two absorbing almost none.

The authors reviewed other studies which indicated that zinc sulfate and zinc acetate might also be absorbed well.

Interestingly, they noted that none of the study subjects were vegan. They didn’t explain why they pointed this out, but it’s good to know that vegans are on their radar.

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References

1. Wegmüller R, Tay F, Zeder C, Brnic M, Hurrell RF. Zinc absorption by young adults from supplemental zinc citrate is comparable with that from zinc gluconate and higher than from zinc oxide. J Nutr. 2014 Feb;144(2):132-6. | link

11 Responses to “Zinc Supplements: Which are Absorbed Best?”

  1. Nick Says:

    Interesting study. Thanks for sharing. They missed zinc monomethionine (ZMA) and zinc piccolinate though, which are other popular forms.

  2. Laury Says:

    Gluconate made me sick so I switched for piccolinate. However I don’t know if it’s effective. I’d be interested to know as well if there is a study with all forms.

  3. Jack Norris RD Says:

    Laury,

    Here is the one study that came up when I searched PubMed:

    http://www.ncbi.nlm.nih.gov/pubmed/3630857

    It suggests that zinc picolinate is as absorbable as citrate and gluconate.

    The Linus Pauling Institute says:

    http://lpi.oregonstate.edu/infocenter/minerals/zinc/

    “A number of zinc supplements are commercially available, including zinc acetate, zinc gluconate, zinc picolinate, and zinc sulfate. Zinc picolinate has been promoted as a more absorbable form of zinc, but there are few data to support this idea in humans. Limited work in animals suggests that increased intestinal absorption of zinc picolinate may be offset by increased elimination (5).”

  4. Brandon Becker Says:

    Is there any scientific evidence that zinc to copper intake needs to be in a certain ratio?

  5. Jack Norris RD Says:

    > Is there any scientific evidence that zinc to copper intake needs to be in a certain ratio?

    I doubt there’s enough to justify worrying about it.

  6. Markus Says:

    “Interestingly, they noted that none of the study subjects were vegan. They didn’t explain why they pointed this out, but it’s good to know that vegans are on their radar.”
    Reason for excluding vegans is that vegans are prone to be zinc deficient and zinc absorption depends on the zinc status (if you are zinc deficient you will probably absorb more zinc). Excluding them helps to reduce the variance.

    “The lower absorption from zinc oxide was almost entirely due to three participants who absorbed much lower amounts, with two absorbing almost none.”
    Please note that the mentioned values are “medians” not “means”, thus the value is not really affected by the non-absorbers.; excluding them leads to median absorption of 50.9% for zinc oxide (see table 2).

  7. Michelle Says:

    After doing a lot of research, I’ve determined that I should probably be taking a zinc supplement. I’m having an extremely hard time finding a vegan option that is a reasonable dose – most seem to be 30mg-50mg. If I took a 30mg dose of zinc every OTHER day, would that be comparable to taking 15mg EVERY day? Thanks so much!

  8. Jack Norris RD Says:

    Michelle,

    I’d suggest to break it in half and take 1/2 per day.

  9. Alex Says:

    Hi, Thanks for summarizing these results. PubMed has several studies showing Zn glycinate more effective than Zn gluconate (and perhaps little benefit of Zn gluconate).

  10. Bob Nichols Says:

    I question some of the zinc numbers. I read a recommendation that I take 45 mg but NOT to exceed that amount because it could interfere with copper absorption and cause nausea. I had been taking 60 mg of gluconate and could detect NO effects. When I switched to zinc Orotate 45 mg stopped the body from converting testosterone into DHT and made a big difference in energy and muscles.
    My guess is that gluconate number is nearer 0%. Zinc Picolinate is much better absorbed but I can not get any firm information and I’m afraid to take 45 mg or any higher because I do not want the nausea Ii got trying to find the proper doseage.
    I Info I refered to said zinc at 45mg would, by stopping the conversion, would stop all prostate problems including cancer.
    The gluconate at 60 mg did nothing, 45 mg of orotate made a BIG
    difference – I went off the prescription medication for prostate.
    Oh, for your info I’m in my mid 80’s.

  11. Jack Norris RD Says:

    Bob,
    This isn’t my area of expertise, but if you’re vegan, you normally don’t have to worry about copper absorption as vegans normally get more than enough.

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