Do children's multivitamin supplements contain too much manganese for developing brains?

What's actually in it

Manganese is a mineral your body needs in small amounts. It helps with bone growth, blood clotting, and metabolism. But too much manganese is toxic, especially to developing brains. It's added to children's multivitamin gummies, chewables, and liquid supplements, often without parents paying attention to the amount.

Kids get manganese from food too: whole grains, nuts, leafy greens, and tea all contain it. When you stack a daily supplement on top of dietary intake, the total can climb well past what's safe for a small child.

What the research says

A 2026 study in PLoS One tested children's multivitamin supplements and found that many contained excessive manganese. The amounts exceeded the tolerable upper intake level for children, meaning a single daily dose could push a child past the safe limit before they even eat breakfast.

Why does this matter? Manganese is neurotoxic at high levels. Studies in children have linked excess manganese to lower IQ scores, attention problems, and impaired memory. The developing brain is far more sensitive to manganese overload than the adult brain.

The problem is partly regulatory. The FDA doesn't require supplement makers to stay below the tolerable upper intake level. They just have to list the amount on the label. Most parents see manganese listed and assume the dose was chosen with their child's safety in mind. Often, it wasn't.

A child's tolerable upper intake for manganese is roughly 2 to 3 mg per day (depending on age), and some supplements contained amounts that would use up most or all of that allowance in a single serving. Add in food sources, and you've overshot.

Check your child's vitamin label for the manganese content per serving. If it's more than 1 mg, that's a large chunk of their daily limit. Better yet, choose a multivitamin without added manganese. Most kids get plenty from food alone.