Update: Zinc

Just added two tables to the page on zinc. Table 1 lists the DRIs and Table 2 lists plant foods high in zinc. Link.

15 Responses to “ Update: Zinc”

  1. Miles Says:

    Dried pumpkin seeds have 2.5 mg of zinc per 1/4 cup according to that same source. Other databases such as have it at 4 mg per 1/4 cup even. Chia seeds have 3.5 mg zinc per 100 grams.

  2. Jack Norris RD Says:


    The chia seed industry should hire you as a spokesperson! I have added it to the zinc table.

    > Dried pumpkin seeds have 2.5 mg of zinc per 1/4 cup according to that same source.

    Which source, this one?

    If so, do you have a copy of that paper?

  3. Miles Says:

    No, no I thought the listings in your table were from the USDA database-

  4. Jack Norris RD Says:


    The problem is that there is no listing for just pumpkin seeds but rather pumpkin and squash seeds, so I don’t want to use their listing. It’s pretty amazing that they don’t have one for just pumpkin seeds.

  5. Laura Says:

    The absorption of zinc is lower from plant foods, so maybe, even if a vegan gets the RDA of zinc, they could still have problems with zinc deficiency.

  6. Laura Says:

    I read that vegetarians need “up to” 50% more zinc, because it’s less well absorbed from plant foods. Vegans might need even more.
    So vegans looking at your zinc page and comparing their intake to the RDA’s may get the wrong impression.
    Dr. Weil suggests that vegetarians take 30 mg of zinc/day.
    He says vegetarian diets are high in copper. More zinc may compensate for the high copper content.
    I’ve found zinc supplements help me sleep.

  7. Jack Norris RD Says:


    I have not seen enough evidence to suggest that vegetarians or vegans need more zinc than meat-eaters. I also have not seen evidence that vegans have particularly high copper intakes.

  8. Laura Says:

    Here’s where the “vegetarians need 50% more zinc” comes from:

  9. Jack Norris RD Says:


    I have seen people *suggest* that vegetarians might need more, but as the page you referred to says:

    “Individuals consuming vegetarian diets were found to be in positive zinc balance (Ganapathy et al., 1981; Hunt et al., 1998)….At this time there are not sufficient data to set algorithms for establishing dietary requirements for zinc on the basis of the presence and concentration of other nutrients and food components.”

    If memory serves, those studies by Hunt were based on diets that were not representative of typical veg diets and were designed to decrease zinc absorption.

    Due to your persistence :), I have added a paragraph to the page on zinc:

    “There is some concern that factors in a vegetarian or vegan diet can reduce zinc absorption, increasing needs for vegetarians by up to 50% (5). A modest zinc supplement of 50 to 100% of the RDA should be safe for those who are concerned. Too much zinc supplementation can reduce copper absorption, so it is best to err on the side of less zinc supplementation or also take copper.”

  10. Renee Says:

    vegans and vegetarians who consume large quantities of legumes and wholegrains may have increased zinc requirements due to the phytates found in legumes and wholegrains. Apparently soaking your legumes and wholegrains will reduce the activity of phytakes, however, I’ve noticed for myself that regardless of my zinc intake of foods, I seem to be generally low in zinc.

  11. Jack Norris RD Says:


    How do you determine that you are low in zinc?

  12. Renee Says:

    using a zinc tally test, plus I can tell when I’m low because my skin breaks out, my sense of taste is reduced and my nails become brittle

  13. Jack Norris RD Says:


    Very interesting. I’ve never even heard of such a thing before, but found this link. I need to check into that more, but won’t have time until I get an article on soy done and am back to blogging frequently.

  14. Renee Says:

    I usually use a liquid zinc supplement/tally test (zinc sulfate) such as Orthoplex Zinc status. You just swish 10 ml of the zinc in your mouth for 10 seconds, taking note of tastes and sensations you experience. The less you taste or feel, and the longer it takes to taste anything the more likely you are to be zinc deficient. If you have a strong reaction to the taste straight away (people usually say it tastes ‘eggy’ or really metallic) the less likely you are to be zinc deficient. I find this test to be quite accurate with my patients (I’m a final year naturopathy student), family, friends and myself

  15. Wendy Says:


    I was reviewing this update and raw hearts of palm are a really good source of zinc. Almost 3,73 mg/100 g.

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