The Bottom Line on Dietary Supplements

How to avoid being duped by your vitamins and supplements

Photo by pina messina on Unsplash

Taking a daily multivitamin or fish oil pill is a common ritual. In fact, Americans spend more than $30 billion a year on dietary supplements.

But a growing body of evidence suggests that popular vitamins and supplements may not always contain what their labels claim, and potentially dangerous ingredients can get into the pills. A recent October 2018 report by California Department of Public Health researchers, published in the journal JAMA Network Open, revealed that more than 700 supplements on the market included unlabeled ingredients found in pharmaceutical drugs, and less than half received voluntary recalls from health authorities. “That’s just the tip of the iceberg,” says Dr. Pieter Cohen, a Cambridge Health Alliance physician who researches supplements.

Here’s everything you need to know about dietary supplements, and how to take them safely.

Do I Need to Take a Supplement?

Estimates suggest more than half of all Americans take dietary supplements, but many may not need them. If you’re eating a healthy diet and don’t have an underlying health condition that prevents you from absorbing nutrients from food, you probably don’t need extra supplements. “For most healthy people who are not on a very restrictive diet, like strict vegan, there is no need for vitamins with only two common exceptions,” Cohen says.

Women of childbearing age should take a folic acid supplement, and post-menopausal women should take calcium supplements if they’re not getting enough from their diet, Cohen says. There are also people at greater risk of developing nutritional deficiencies who can benefit. For example, women who have heavy periods, people with cancer, and people who frequently donate blood are all more likely to be iron deficient, according to the National Institutes of Health (NIH). In this case, iron supplements may be recommended by a doctor.

“The bottom line is that people should talk with their health care provider for advice,” says Carol Haggans, a nutrition scientist and consultant to the Office of Dietary Supplements at the NIH. That may seem like obvious advice, but estimates suggest that…