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Zinc Has Many Health Benefits, But Don’t Overdo It

Genes Mentioned

How common is zinc deficiency?

Was I deficient?

I believe I did have a mild zinc deficiency (and later confirmed the deficiency with a Spectra Cell test) as a side effect of transitioning to a more plant based diet. It should be noted that while vegetarian and vegan diets are typically lower in zinc, it is possible to maintain healthy zinc levels on plant forward diets with proper planning.

In the western world, acute severe zinc deficiency is rare, but as with magnesium deficiency, it’s a real issue that can go unnoticed. However, in the developing world, where zinc deficiency is far more common, it can cause stunted growth, severe immune system dysfunction and even early death. 1

It has been estimated that zinc deficiency impacts as many as 2 billion people in third world countries. 2

Why would you have a zinc deficiency?”

First, mild zinc deficiency like we see in the West, is largely sub-clinical, meaning it’s very difficult to identify.

Phytic acid rich foods can block zinc absorption

I had been eating a lot of food, like oatmeal, beans, and nuts that are high in phytic acid, which can block mineral absorption. 3

Finding the right dose of zinc

According to the National Institute of Health, the upper limit for dosing zinc is 40 mg a day. This seems like a very high dose to me if the plan is to take zinc long term.

When I believed I was suffering from mild deficiency, I felt my zinc levels rapidly stabilize with just a few days of 50 mg dosing, and I did take it a bit too far, so much so that I developed some side effects like an upset stomach and dizziness.

You do not want to overdo it with zinc. Taking too much zinc will eventually draw down your copper and magnesium levels, both of which can cause health issues. 5 I now find that about 15mg of zinc 3-4 days per week is ideal for me.

With those personal factors out of the way, what do studies have to say about zinc supplements?

Are there proven benefits?

Benefits of zinc supplements

Zinc boosts the immune system

The research is clear that zinc supplements can have a positive impact on the immune system through a number of different mechanisms.

The two primary drivers appear to be IL-2 activation and the corresponding increase in T cells. 6 7 T cells “hunt down” and kill bad cells, like germs/infections and cancer cells.

Zinc increases testosterone

There is evidence that supplementing with zinc can help the body make more testosterone.8

Histamine intolerance and allergy

I’ve blogged a good bit about histamine intolerance. Histamine is released from immune cells when the body perceives a threat, both real (a virus), or imagined (pollen). When you add the histamine in food and genetic predispositions to the equation, some people begin to develop symptoms.

Zinc has been shown to inhibit the release of histamine from mast cells, which is a blessing for anyone who is trying to bring their histamine levels under control. 9

Note: if you’re looking at zinc because of an issue with histamine, remember copper. Zinc draws down on copper levels and copper is a co-factor for diamine oxidase production, the enzyme that clears extracellular histamine. For more, check out our AOC1 gene page.

Zinc and infectious disease

There are multiple studies, in both the elderly and in younger populations, which found zinc plays an important role in combating infectious disease.

Double blind, placebo controlled studies (the gold standard of studies) found zinc supplementation reduced the severity and incidence of diarrhea in infants and young kids in India. 10

This study found that zinc supplementation saved the lives of children in developing countries with lower respiratory tract infections. 11

Supplementing with zinc has also been shown to decrease the number of infections in the elderly. 12

As we mentioned in a men’s health post Gene Food did on chronic prostatitis, adequate levels of zinc in the prostate are associated with increased ability to ward off trichomonas vaginalis, a parasite that can infect the prostate gland. This makes sense because zinc levels are 10 times higher in the prostate than in other soft tissue. 13

This meta-analysis found significant reduction in the duration of cold symptoms when patients were administered doses of zinc > 75mg.

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Zinc acts as an antioxidant and decreases oxidative stress

This small (10 subjects), but double blind, placebo controlled study found supplementing with zinc decreased oxidative stress markers in patients who took 45 mg of zinc (again, a large dose in my view).

Put simply, our mitochondria use oxygen as part of the process of generating ATP, which is the energy currency of the body. This is a good thing. But as with any process of burning fuel, there are waste products associated with oxygen metabolism. One of these is called superoxide, which is a harmful free radical that can damage our cells if left unchecked.

In order to neutralize superoxide, our bodies generate a native, or “endogenous,” antioxidant called superoxide dismutase, or SOD. SOD converts the harmful free radical superoxide into the much less harmful hydrogen peroxide, which our bodies further break down from there. But when we lack SOD, and people born with certain variants in this gene are thought to have lower SOD2 levels, our bodies aren’t as good at mopping up free radicals.

Still with me?

Good, because SOD is made up of both copper and zinc.

In our Guide to Nutrigenomics, I list zinc as a nutrient that directly enhances expression of the SOD3 gene, as well as for ADA. To quote Aaron:

Zinc, along with copper, is one of two metal co-enzymes required by SOD3 to function 7. There is no evidence demonstrating a beneficial effect on SOD3 activity following zinc supplementation. However, zinc has been shown to demonstrate an antioxidant capacity through unknown means 9, therefore supplementation may benefit those carrying the risk ‘G’ allele of C691G.

Closing thoughts

I think the bottom line here is that, whether you supplement, or eat foods rich in zinc, zinc is a mineral that should be on your radar. It has proven health benefits. However, at large doses over long periods of time many people will experience side effects.

Dr. Aaron Gardner, BSc, MRes, PhD

Dr. Aaron Gardner, BSc, MRes, PhD is a life-scientist with a strong background in genetics and medical research, and the developing fields of personalized medicine and nutrition. Read his full bio here.

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  1. Kevin says:

    I started supplementing with Zinc about 6-7 years ago. I felt the effects it had on me immediately (focus,pleasure,mood booster). I once was taking 50mg of zinc a day and after reading that 50mg is a high dose I cut back my dose to 25mg a day. I felt a lot better on 25mg instead of 50mg that’s for sure. 25mg a day reduced the nausea (my worst side effect) to almost zero as well as the rest of the side effects from it. So I have been on 25mg the past 6 years. It has so many great functions; anxiolytic, anti-depressive effects, sexual boost, and also a great stamina booster. I take an SSRI and experienced some sexual dysfunction from it which went away for the most part over time. I will say the SSRI+Zinc combo helps keep testosterone levels up and works great for me. Zinc is also one of the FEW minerals that help ssri induced or stress induced loss of pleasure (for me anyways). 25mg of Zinc a day work for me as the 50mg made me tired all day and actually gave me anxiety. So like they say go slow! 10-25mg a day max. thanks and have a great day y’all

    • Great insights, thanks for sharing Kevin. I 100% agree that 50mg of zinc is a major dose. I certainly don’t handle doses like that well for any extended period.

  2. Keith says:

    Zinc Bis-Glycinate is a (way?) better form than Zinc Picolinate, for absorption + no side effects—while still being on the cheaper-end – unlike Zinc Carnosine, which is very pricey, from being backed by clinical trials *specifically* for IBS/IBD/leaky gut, and thus causing people to jump on that expensive ‘bandwagon’. (Though, really it’s a matter of my personal choice not to spend that much money, despite my having IBS lately… which I’ve been curing through other means, anyway.)

    The form by Pure Micronutrients (very good reviews, and the least amount of Amazon fake reviews according to Reviewmeta’s algorithm) is a 25mg formula that I just took 1 pill of today. And I already feel way better, less stressed, etc. I slept pretty much instantly for 2-ish hours afterward, and could barely even tell I was sleeping or for that long, even thinking I’d only fallen asleep for a few minutes – and snoring very loudly according to family, than any other snoring I’ve ever done. (The dog went into the other room, even.)

    I really felt like my nasal passages were a lot clearer (still continuing to be clear!), especially after some lingering mucus still present, from weeks later after I’d had to pop 2 Claritins and 2 Airbornes from insane allergies I’d never experienced prior. (I think I’d been suffering from medium/heavier IBS, from November 2018’s overuse of antibiotics—which I’ve been slowly curing by using Heather’s Tummy Fiber from the Acacia tree in Africa. And it really felt like my weakened gut was letting cold bugs/allergy problems into my system, without that natural gut immunity.) My mucus might’ve actually still been present right up to the moment of taking this zinc. But I actually don’t even remember… just glad the incessant clogging and the occasional/seldom albeit massive ‘kerchief blowing is gone from my left nostril.

    Medically, the upper limit is 40mg, so it’s probably not good to take two of their 25mg Zinc Glycinates, and get any further desired zinc from foods. (Some people go for 70mg, or somewhere around there, for some likely just quicker/more potent benefits. But they’d probably tell you they’ve only done it for the short-term!) Any form of zinc that is not the absolute best absorption method is a definite cause for negative side effects, because of the extra processing your body must go through. Zinc Orotate is supposedly even ‘better’ absorbed, but I feel that’s fairly new territory; and regardless, I’ve not found a single better formulation than Pure Micronutrients—since every single, *immense* amount of formulations I’d looked at [probably even more I didn’t look through, and feels like a miracle I found Pure Micronutrients at the very last second before giving up, and even having bought Thorne’s Picolinate form + having to ask to return it], prior to finding that company, had Magnesium Stearate or Stearic Acid, or other questionable fillers in it. (Some say those aren’t bad, perhaps even because “it’s a small amount” – but try taking even just 3-4 different supplements, all of them with that stuff in there!)

    Supposedly to balance the copper, eventually you’ll want to take some days off of the zinc (not sure how many days) and start taking a tiny amount of copper, from probably natural sources, or *perhaps* a very good supplement, which I haven’t bothered looking for. Shiitake Mushrooms have all the related co-factors you need: manganese, zinc, copper, forgot what else! Anyway, I do believe that’s the end of my understandings from thoroughly thinking and cross-checking about this topic.

    • Shawn, I am sure this answer varies from individual to individual, but 10 mg is closer to the recommended daily doses than many of the supplements which offer mega doses.

  3. Carlajane White says:

    How far apart should I take the zinc tablets ,I’m taking 2 per day plus cuprimine 2 time a day I have Wilson s disease,too much copper

  4. Munny says:

    Hi John,
    A close friend of mine took Zevit which contains 41.4 mg Zinc Sulphate for three solid years! Although this was 30 years back she has developed arthritic symptoms, migraine and has nausea throughout the day. I suggested she drink water from a Copper container and also start taking Magnesium. My query is do you think her Zinc overdose would have such long lasting effects?


    • Hey Munny, thanks for the comment. This is probably a question for a physician. While taking that amount of zinc for that long definitely goes against health guidelines, it’s hard to say what caused the symptoms. I do think it’s fairly common for people to make themselves sick by taking the wrong supplements at the wrong time and at the wrong dose.

  5. Tarak Kadia says:

    Just discovered this site and I love it. Seems well researched. One issue. The Immune Engine link from this article doesn’t work and a google search of Immune Engine did not lead me to any supplement. Where can I go to find a zinc supplement that is low dose enough for regular use without too many extraneous ingredients? I presume I need one that comes with copper (and maybe even magnesium?) since my histamine levels are high and I’m an undermethylator.

  6. Sherry says:

    I took 50 mg and noticed nausea severe dizziness which threw me into slight panic attack

    • Sharice says:

      You may have high copper. When you supplement with Zinc, especially higher dosages, you can cause copper to dump and that causes anxiety. Start very low and work up if needed.

      • Tracey says:

        How long did the panic attack/anxiety last? I ask because I was taking 30mg (daily) for a little over a week. I stopped taking it for a week now but really struggling with the anxiety etc. I’ve never felt like this, so glad I came across this post.

  7. Diana Nieto says:

    2 weeks ago i started supplementing with copper ask me why ? I been suffering from lower back pain , seen drs but they all said it was sciatica . so at first taking copper pain went away at the same time i deleted alot of high histamine foods that were causing me issues ,but then i started to feel bad and i also got a yeast infaction brainfog confusion . so i stopped and started taking zinc 50-100mg at day and avoiding rich copper foods . but now i feel worst and im getting skin rashes . what should i do ? I just had a baby and i feel guilty because im never happy my poor memory is causing problems 🙁 please help

    • Hedawa says:

      Diana, take magnesium and selenium. They say that selenium is find in walnuts, selenium helps the brain function. I also use Magnesium and msm powder. I feel more power and mentally more clear. Less phone radiation is also very important.

  8. Shawn says:

    With the 5mg zinc dose, would you still need cooper to balance it out or that dose is too small to cause any problems long term?

  9. Joe says:

    John, larger dosages of zinc really seemed to improve symptoms of an autoimmune issue I was dealing with but with some negative side effects. Can you go into more details on what side effects you experienced with the larger doses?

    • Hey Joe, it’s been awhile since I experimented with high doses of zinc, but dizziness was definitely one of the side effects for me. I now stay around the 7-8mg per dose “sweet spot.”

  10. Rene G Volpi says:

    I find it very peculiar that the supplement manufacturers almost consistently make the 50 mg the regular dosage amount in the bottles. Don’t they know such high amounts could cause issues? Just wondering.

  11. Maria says:

    Have you ever heard of a small dose of zinc helping someone within five minutes? Every once in awhile my glands under my neck feels sore and I feel hot and generally unwell. Almost as if I am on the verge of getting a cold. I noticed that if I take a zinc lozenge of 5 mg, which I know is a small one, all of my symptoms disappear. I felt sick like this last night and I took a zinc lozenge and I felt 100% better. Not only did I feel better, but I also fell asleep extremely quickly. I usually can’t fall asleep until 3 in the morning, but I was out like a light at 12 a.m.. I usually don’t remember my dreams at night, but last night I had a lot of them, which I like. Over the years I always thought that I had a zinc deficiency, as taking zinc makes whatever this is go away. But what’s weird is that my zinc levels have always come back normal. It is one of the few minerals that is in its proper place. I had various forms of testing, one of which was hair analysis. From everything I’ve read on the internet, it doesn’t seem like zinc should have this quick of a positive effect on people.

    Thanks for this article. It was extremely helpful. I loved learning how it helps boost the immune system.

  12. Gianluca says:

    Very interesting article!

    I am actually takin some zinc supplement now (22mg picolinate) and i think it is maybe too much.. i feel like it is protecting me from stress bit at the same time creating some brainpeople confusion.. i am a bit concerned of depleting too much copper.. i m tjinking to cut it down to lower doses (1/4 of a pill o, around 5mg).. how many days did you supplément at high dosages before slowing down?

    • Hey Gianluca, I can’t say, you’d have to ask your doctor that. Having said that, if you’re having doubts best to stop altogether or go down to one small dose every 5 days or so. 22 mg a day is a pretty hefty daily dose of zinc over time.


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