Comments on: Vegans Should Probably be Supplementing with Zinc

By: Pauline Pantaleo

Pauline Pantaleo — Sun, 08 Mar 2026 06:07:42 +0000

I have SLE Lupus and had a non healing wound on my shin for about 3-4 years. I had started taking zinc, mine is 50mg but I take it every few days.

By: JackNorrisRD

JackNorrisRD — Sun, 19 Oct 2025 01:30:01 +0000

In reply to Simone.

Simone,
There doesn’t seem to be much evidence for what is too much zinc over the long term. So, I’d suggest not taking more than seems necessary. For people who don’t have symptoms of zinc deficiency, I wouldn’t recommend more than an extra 10 mg.

By: Simone

Simone — Fri, 17 Oct 2025 17:03:20 +0000

Good morning, and congratulations on the very helpful article.
I take 10 mg of zinc in a multivitamin and get the rest from my diet (I eat a lot of legumes). Do you think I should also take a 15 mg zinc supplement? Calculating 10 mg from the multivitamin, plus the zinc supplement (another 15 mg) and my normal diet (about 10 mg), would be 35 mg. Could this be dangerous in the long term?

By: JackNorrisRD

JackNorrisRD — Thu, 18 Sep 2025 14:47:49 +0000

In reply to El. El, Thank you for the links. I added a section, Absorption Differences between Zinc Supplement Formulations. I agree that most nutrient formulations have some differences in absorption rates, but as you implied, in most cases supplementing at all is the most important thing.

By: JackNorrisRD

JackNorrisRD — Thu, 11 Sep 2025 14:00:06 +0000

In reply to Torin Doyle.

Torin,
I don’t think that’s necessary—there aren’t negative effects of 25 mg that I’m aware of.

By: Torin Doyle

Torin Doyle — Wed, 10 Sep 2025 08:45:25 +0000

In reply to JackNorrisRD. Hi Jack. There's another version with 15mg. I will opt for that the next time. In the meantime, would it be best if I took my 25mg supplements every second day?

By: JackNorrisRD

JackNorrisRD — Mon, 08 Sep 2025 15:22:55 +0000

In reply to Torin Doyle.

Torin,
I’d cut them in half to meet my recommendations for closer to the RDA. The upper limit is 40 mg, but those are based on acute symptoms rather than any longterm impacts. I wouldn’t be worried about 25 mg, but I also don’t see a reason to take that much so might as well be cautious unless someone has a reason for requiring more. If it were me and I couldn’t cut them in half for some reason, I’d use that bottle up and then get a smaller amount next time.

By: Torin Doyle

Torin Doyle — Mon, 08 Sep 2025 12:43:49 +0000

Hi Jack. I take a supplement of 25mg once per day at lunchtime. Is that too much? I eat a tin of baked beans every day and on 6 days a week I eat oatmeal for breakfast. I also have lentils in my dinners for 4 to 5 days a week.

By: El

El — Thu, 04 Sep 2025 12:05:55 +0000

In reply to JackNorrisRD.

Happy to share Jack, and would be interested in your thoughts:
https://academic.oup.com/jn/article/144/2/132/4637670
https://aspenjournals.onlinelibrary.wiley.com/doi/10.1177/0148607195019005393
https://www.tandfonline.com/doi/abs/10.1080/07315724.1994.10718389

B12 is another case as you mentioned, although it’d be nice to have studies truly exploring the impact (or lack thereof) of MTHFR gene mutations on cyanocobalamin versus methylcobalamin supplementation.

Generally speaking though, differences between supplemented nutrient forms are rather commonplace, although perhaps not as critical as supplementing at all to begin with, or dosages.
For example, magnesium oxide is notorious for poor absorption and negative side effects, kelp iodine for inconsistent dosages, et cetera.

By: JackNorrisRD

JackNorrisRD — Thu, 04 Sep 2025 02:24:49 +0000

In reply to JackNorrisRD. Vitamin B12 is an exception, since there's reason to believe that cyanocobalamin is absorbed at a much higher rate than other forms.