How to Tell if You’re Taking too Much Zinc

Zinc supplements are popular for boosting immunity. If you’re taking zinc to ward off illness, watch out for these signs that you’re taking too much zinc.

My son is in preschool, which means that he brings home a new, fun cold or other illness at least once a month, and that’s totally normal. But I don’t have to like it. Whenever my kid gets a runny nose, I start taking zinc supplements and vitamin C to help my immune system fight off whatever germs we’re dealing with this time. Because a sick kid is no fun, but caring for a sick kid while you’re also sick is even worse.

According to the National Institutes of Health, we need zinc to support immune health. Our bodies use zinc to heal and to ward off disease, and some studies have found that zinc supplements can help reduce oxidative stress and inflammation. Others have found that zinc supplements help reduce both how often you get sick and for how long, if you do come down with a cold.

Our bodies need zinc to function healthily. Care2′s Zoe Eisenberg explains that it’s an essential mineral for cellular functions and a healthy metabolism. She also notes that zinc helps balance our hormones. We need zinc to stay healthy, but it’s possible to overdo it in the zinc department, as well.

Symptoms of Too Much Zinc

So how much is too much zinc? Like many other supplements, zinc has some nasty side effects if taken in excess. Here are some symptoms which could indicate that you’re taking too much zinc, according to the NIH and WebMD:

  • nausea
  • vomiting
  • loss of appetite
  • stomach cramps
  • diarrhea
  • headaches
  • fever
  • coughing
  • fatigue

Ironically, taking too much zinc in the long term can actually harm your immune system. The NIH also warns that taking too much zinc for a long period of time can deplete your copper levels and lower your “good” cholesterol levels.

Too Much Zinc vs. Just Enough

When we talk about how much of any vitamin or mineral the body needs, there are really two numbers to look at: recommended daily allowance (RDA) and Upper Limit. The RDA is how much of a nutrient your body needs to avoid deficiency. The Upper Limit is how much most people can take before they start to see negative side effects.

Here are the RDAs and Upper Limits for zinc:

RDA and Upper Limits for Zinc

Remember that both animal products and some plant foods also contain zinc, so you need to account for diet when calculating your daily zinc intake.

If you’re taking close the Upper Limit for zinc to avoid catching a cold, don’t do it for more than a week or two. To reduce the duration of a cold, stop taking zinc supplements when your symptoms disappear. Infants and children should not take high doses of zinc—stick to the RDA when it comes to kids, unless your pediatrician says otherwise.

Some companies sell a zinc nasal spray for cold and flu, but this supplement has caused some users to experience a permanent loss of their sense of smell. Zinc syrups and lozenges are a better short-term option, if you’re looking to take zinc for immune support.

Related at Care2

Zinc supplements are popular for for boosting immunity. If you're taking zinc to ward off illness, watch out for these signs that you're taking too much zinc.

Image Credits: All images via Thinkstock.


Melania Padilla
Melania P9 months ago

Thank you for sharing

heather g
heather gabout a year ago

Useful info, thanks

Mona P
Mona Pietschabout a year ago


Marc P
Marc Pabout a year ago

thank you for sharing!

Winn Adams
Winn Aabout a year ago


Winn Adams
Winn Aabout a year ago


Rob and Chloe N
Rob Chloe Sam Nabout a year ago

Interesting article, Thank you for sharing this.

Angela A
Angela Kabout a year ago

thanks for sharing

Telica R
Telica Rabout a year ago

Thanks for sharing

Gino C
Past Member about a year ago

thanks for this