Headaches After Going Vegan? Here’s Why…


I’ve seen more than a few complaints from vegans, particularly new ones, about getting frequent headaches.

So, I spent a few hours doing research on the topic to try to figure out what’s causing these headaches.

There’s no definite answers, but I did find several potential causes worth considering.

Keep in mind that this is not medical advice. If you’re having significant pain on a regular basis, see a doctor, there might be more than a dietary issue going on.

Vitamin and Mineral Deficiencies That Cause Headaches

Many of the potential causes I found were anecdotal. But there are some nutrient deficiencies that have been proven to cause headaches, so let’s start with those.

  • Vitamin D deficiency – While this usually takes at least a few months to form, a vitamin D deficiency can lead to frequent migraines. Vegans can struggle to get enough vitamin D if they don’t get much sun. Consider a vegan vitamin D supplement if that’s the case.
  • Magnesium deficiency – It’s not crystal clear, but some evidence does point to a magnesium deficiency causing headaches. Focus on vegan foods high in magnesium if worried about this.
  • Vitamin B2 (riboflavin) deficiency – There’s also a potential link between a B2 deficiency and migraines. I’d only worry about this if you’re not really eating vegetables. Here are the best vegan food sources of riboflavin for reference.
  • Dehydration – If for some reason you’re not getting as much liquids as you were before going vegan, it may explain minor headaches.
  • Salt – Some people start eating a lot healthier after going vegan. Less processed food that’s high in salt, and more whole foods. While you don’t want too much salt, too little may also trigger headaches. There’s not much salt naturally in foods, so you may need to add a bit extra.

So how do you know if you have a deficiency? Ideally, get a blood test from your doctor.

But if you can’t do that for some reason, use a free tool like Cronometer to track your diet for a few days and see if there are any obvious deficiencies.


Other Possible Causes of Headaches for Vegans

The causes in this section are less studied and proven as far as evidence goes.

I included them because they were often anecdotally reported to be causing headaches.

Too Many Nutrients

This is rarely a problem just from eating food, but if you take multiple supplements it’s possible.

I saw multiple reports of vegans worried about iron and B12 deficiencies, so they took way too many supplements of either kind.

The Dreaded “Detox”

I hate the word detox, but it came up a lot when researching for this post.

A better term would be “adjustment period.”

When you switch to a drastically different diet, as many vegans do, it takes your body some time to get used to it (your gut bacteria in particular).

If you all of a sudden stop consuming something that you’re used to, like dairy or sugar, it can take weeks or even months to fully get used to it. Dairy withdrawal and meat withdrawal appear to be real things, even though they haven’t been studied that much.

Coffee is another big one when it comes to headaches. If you stopped drinking it after going vegan, it can give you headaches for a while.

A Reaction to New Foods

There were also anecdotal reports of headaches being caused by eating more of certain foods.

Since it’s common to introduce new foods into your diet after going vegan, this could be causing your headaches. Try eliminating certain foods you’re worried about for a few days and see if that helps.

Here’s a compilation of different foods that may cause headaches in some:

  • Processed food in general (if you eat a lot)
  • Peanut butter
  • Legumes (beans, lentils)
  • Sourdough bread
  • Baked goods with yeast
  • Artificial sweeteners

Your Headaches Might Not Be Related to a Vegan Diet

Finally, your headaches may have nothing to do with being vegan at all.

It could be a completely unrelated infection.

It could also be stress. Going vegan is stressful.

You have less certainty and possibly anxiety about what to eat, and it can affect social situations as well. If you’ve been feeling extra stressed lately, try and address that and see if it helps your headaches.

About the author

Dale Cudmore

Your friendly neighborhood vegan from Toronto. I've spent over 6 years as a freelance nutrition writer and researcher. During this time, I've tested over 50 vegan protein powders, and over 100 other types of vegan supplements.

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