More than a third of all Americans take a multivitamin daily, according to the National Institute of Health, and it's possible to get virtually every vitamin the human body needs in supplement form. Many of us include them in our daily routines in the pursuit of making our immune systems and other bodily functions stronger. However, some grand claims have been made about vitamin supplements — from vitamin C's power for curing colds to vitamin D's potential for curing almost anything — that have, under scientific examination, been discovered to be exaggerated or untrue. After all, supplements are meant to supplement our food, which is where we're meant to get the vast majority of our vitamins. There's a lot about that daily pill you may not know.
Science is also still discovering many things about vitamin supplements and how they may help or hinder health, including the genetics that mean some of us respond differently to others. Some vitamins are definitely necessary for various groups; doctors agree, for instance, that folic acid is a necessary supplement for pregnant people because of its proven ability to help prevent birth defects. However, vitamins are more complicated than they might seem. Here are some quickfire facts about vitamins, their history, and their impact on human health.