July 2025
Vitamin and herbal supplements are seen as “natural” products — but that doesn’t meanthey can’t make you sick. According to the New England Journal of Medicine, an estimated 23,000 emergency department visits each year are linked to side effects of dietary supplements.
Here’s how you can prevent adverse or dangerous reactions:
Understand UL and RDA
The tolerable upper limit (UL) is the maximum upper amount of a vitamin you can take that
is unlikely to cause adverse health effects. Some supplements are sold in doses higher than the UL.
The recommended daily allowance (RDA), is the average daily level you need to meet nutrient requirements. When counting UL and RDA, be sure to include food sources of these nutrients.
Don’t take certain supplements on an empty stomach.
Iron supplements, and multivitamins with iron, are often hard to digest.
Fat-soluble vitamins — A, D, E, and K — need fat to be absorbed better by your body. Side effects of taking these on an empty stomach can include nausea and stomach pain. Eat a small meal or snack when taking these.
Ask your pharmacist about vitamin/medication interaction.
Supplements can impact how medications work, stop them from working, or increase their side effects. Some supplements marketed for brain health can cause dangerous — and sometimes fatal — reactions when taken with certain mental health drugs. It’s a condition called serotonin syndrome.
Tell your doctor about all the supplements you take. Remember, the U.S. Food and Drug Administration does not approve dietary supplements for treating specific conditions.
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