Why Does My Multivitamin Give Me an Upset Stomach?

If you've had nausea, dizziness, heartburn, and even vomiting after taking a multivitamin, you may have given up on supplements as a result of your bad experience. The general public holds a number of misconceptions about this side effect. For the wrong reasons, some blame their own sensitive stomachs, others blame the vitamin itself.

It's true that some people will have more sensitive stomachs, and be more prone to heartburn or dizziness after taking a multivitamin. This can be mitigated by taking the pill alongside a meal, but it still leaves the question, why do we need to accompany the vitamin with food in the first place? The culprits are usually iron and zinc, two relatively irritating nutrients that are nonetheless very important for your heath.

Many multivitamin products will supply 100% of the Recommended Daily Amount (RDA) of iron and zinc, but that may be too much for some people to comfortably take at once. If you use the popular One-a-Day vitamins and get an upset stomach from it, you could consider cutting the pills in halves.

Another option is to find a multivitamin that doesn't make you vomit, and there are a few options that will be gentle on your stomach on account of their lower iron and zinc content. A company called New Chapter has an Organics product line with offerings such as Every Man and Every Woman Daily that might alleviate your discomfort. Some happy customers mistakenly believe this is due to the organic qualities or their US origin. The women's version has less iron and zinc, while the men's version omits iron entirely. The differences exist because women are more prone to iron deficiency than men (who may not need an iron supplement at all). It should be safe to take less than 100% of the RDA for iron and zinc, as the vitamin is not meant to be your primary source of nutrients. That's why they are called supplements, not sustenance!

That's why it's important to eat a healthy and well-rounded diet, whichever of the above approaches you take. Also remember: an upset stomach should not stop you from taking your daily multivitamin. At least try these suggestions, always being mindful to follow directions and take the vitamins with a meal.

Additional reading:
"Can Vitamins Upset Your Stomach?" at DrWeil.com
"Supplements 101" at Electroherbalism