Taking a multivitamin
Roughly 40% of Americans take a daily multivitamin, according to the Centers for Disease Control and Prevention. Unfortunately, they don't appear to making us any healthier.
A trio of studies published in 2013 found no evidence that supplements could prevent or slow down chronic conditions like heart disease and cancer among people who are well-nourished (like most Americans).
In an editorial published alongside those studies, a group of doctors also addressed multivitamins specifically, writing that there's "no substantial health benefit" to taking them.
If you think that you might be deficient in any nutrients, talk to a doctor before you buy vitamins.
[Photo via @trsinka]