Why do some vitamins make me nauseous?

Vitamins can cause frequent nausea. In this video, Dr. Oz discusses the reasons why vitamins cause nausea.

Not all vitamin supplements list "nausea" among their potential side effects, but some do. For example, taking high doses of iron supplements can lead to nausea and vomiting, but sometimes these side effects can be avoided by taking smaller doses a few times a day. Vitamin C may cause nausea, vomiting, stomach cramps and headache, but these symptoms are less likely with low doses. Other nutrients that may cause nausea or an upset stomach include niacin (vitamin B3), vitamin A and vitamin D.

Talk to your doctor. If you need to take these supplements, your doctor may be able to suggest ways to take them (such as with a meal) that are less likely to cause nausea.