Side Effects of Iron Supplements for Vegans


Iron deficiency is one of the most common vitamin or mineral deficiencies.

But for vegans, it’s even more likely.

While there’s plenty of iron in vegan foods, it’s all non-heme iron, which is poorly absorbed by the body (compared to heme iron in meat).

Most vegans can get enough iron in foods, but if you’re struggling, turning to supplements is your only option left.

I’ve written a detailed guide to the best vegan iron supplements if that’s relevant to you at this time.

Unfortunately, iron supplements often cause symptoms, regardless of whether you’re vegan or not.

This is usually due to :

  • The form of iron used in a particular supplement
  • Getting too much iron (easily possible with supplements)
  • Other causes that you’ll need to see a doctor for (like hemoglobin disease).

Iron supplements are one of the few supplements where you should really see a doctor before taking if possible.

The Common Symptoms of Iron Supplementation Side Effects

Iron supplements can cause a wide array of side effects, which includes:

Those are mild symptoms of iron poisoning, but if you really overdo your iron supplementation intake, it can even lead to death.

Iron poisoning is rather common in children, so keep any supplements away from them.

What You Can Do If You’re Experiencing Side Effects

Not all hope is lost if you do experience these side effects.

Here are some potential practical solutions:

  • Don’t take supplements with food or drinks. Try to take it on an empty stomach (source).
  • Switch supplements. There’s a lot of variety in vegan iron supplements. One might cause you issues while another won’t.
  • Reduce the dose. Supplements often have multiple times the RDA for iron. Take 1/3 or 1/2 the dose and see if that clears up your symptoms.

Do those one at a time so you know what helps (if anything).

Alternatively, here are a few alternatives to using an iron supplement:

  • Get a lucky iron fish. You add these to your frying pan, and a bit of iron leaches into your food.
  • Use a cast iron pan. Similar reasoning to the iron fish. Some studies have shown some evidence that this cooking with iron pots can be helpful.
  • Add more vitamin C to meals. Vitamin C greatly improves iron absorption. Here’s a detailed breakdown of how much vitamin C you need for optimal iron absorption.
  • Eat more iron-rich foods. This is ideally the first option you try. Here’s a list of the best vegan iron sources.

Now that you’ve read all this, you’re much more informed than the average person taking iron supplements.

If you have any questions about iron supplementation and side effects, just let me know in a comment below.

About the author

Dale Cudmore

Your friendly neighborhood vegan from Toronto. Chemical engineer turned semi-professional soccer player and freelance nutrition writer. I've been vegan for years and try to make life easier for others by sharing what I've learned.

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