Is it possible to overdose on vitamins?

Recommending and taking supplements is most likely incredibly common in your practice and among your patients.

According to the 2015 CRN (Council for Responsible Nutrition) Consumer Survey on Dietary Supplements, more than 80 percent of American men and women questioned reported having a certain level of confidence in the safety, quality, and effectiveness of vitamin and mineral supplements.

However, what most people don’t realize is that it is possible to take too much of these nutrients in pill, powder, or liquid form, which makes them potentially more harmful in nature than good.

When supplements become too much

“Most vitamins and minerals have upper limits and can cause health problems if consumed in excess,” says Carol Haggans, MS, RD, Scientific and Health Communications Consultant for the National Institute of Health’s Office of Dietary Supplements. Or, put simply, an overdose type of situation can occur if someone takes too much of a nutrient that is actually intended to increase health.

Take vitamin B, for instance. “Certain B vitamins, like vitamin B12, are considered safe at high doses,” says Haggans, “but high doses of others, such as vitamin B6, can be toxic, causing severe nerve damage. Vitamin A is another nutrient that can cause serious problems at high doses, including birth defects if a woman is pregnant,” says Haggans. But it gets even more complex than that.

Even if a vitamin hasn’t been found to be toxic in doses higher than the RDA (recommended daily allowance), “this doesn’t mean that consuming more than the recommended amount provides any benefit,” says Haggans. “It’s also important for people to know that dietary supplements can interact with certain medications or surgical procedures,” she adds, making these vital considerations as well.

Vitamin overdose prevalence and safety

“It’s rare to get a vitamin or mineral overdose from foods and beverages, and taking a basic multivitamin/mineral supplement should be safe for healthy people,” says Haggans. “But people who take individual vitamin or mineral supplements and who consume foods and beverages that are fortified with extra nutrients might consume some nutrients at levels exceeding the upper limits.” Sometimes overdosing on these nutrients happen when supplements get in the hands of people who simply don’t understand how to best take them, like can happen with kids.

“It’s very important to keep all dietary supplements out of the reach of children,” warns Haggans, citing that “between 1983 and 2000, at least 43 U.S. children died from consuming supplements containing high doses of iron.” Fortunately, the Food and Drug Administration (FDA) responded and, “In 1997, the FDA began requiring oral supplements containing more than 30 mg elemental iron per dose to be sold in single-dose packaging with strong warning labels,” shares Haggans, adding that, “At the same time, many manufacturers voluntarily replaced the sugar coating on iron tablets with film coatings.”

When vitamin levels are too high

“Symptoms of excessive intakes vary widely depending on the nutrient and dose,” says Haggans. “They can be mild like GI disturbances (nausea, diarrhea) or serious like coma and even death.” Still, there are circumstances in which taking higher-than-normal doses is recommended.

For instance, when someone has a deficiency of a certain vitamin or mineral, the “health care provider might recommend a relatively high dose of that nutrient for a short period of time to boost their levels back to normal,” says Haggans. “And in some cases, people might have trouble absorbing nutrients from foods. For example, some people have trouble absorbing the vitamin B12 that is present naturally in food, so they need to get extra vitamin B12 from a supplement or an injection.”

Helping patients avoid vitamin overdose

To help protect patients from overdosing on the vitamins and minerals designed to help them enhance their health versus hurting it, Haggans suggests that patients “look carefully at the supplement facts label of any dietary supplement they are considering taking, and talk with their health care provider for advice. People shouldn’t try to correct a nutrient deficiency on their own,” says Haggans, “or ‘guess’ at how much they need.”

Because some research has found that hesitancy behind providing this type of information exists for certain patients, “DCs and other health care providers should ask their patients about dietary supplements and talk in an open and non-judgmental way about this topic,” suggests Haggans. This should help keep the lines of communication open, enabling you to provide the information your patient needs.

If you’re interested in learning more about vitamins and their potential impacts when taken in higher-than-recommended dosages, the Office of Dietary Supplements has many online fact sheets for most any vitamin or mineral available on the market today. These can be given to your patients as well, providing them the information necessary to make the best decision possible for their own physical health.