NEW YORK (AP) — A new study is drawing attention to a rise in poisonings in children involving the sleep aid melatonin.

Last year, U.S. poison control centers received more than 52,000 calls of children consuming worrisome amounts of melatonin, a hormone that helps control the body’s sleep cycle.

That's a six-fold increase in what was reported about a decade earlier.

Most such poisonings are children ages 5 and younger who accidentally got into bottles of melatonin.

The Centers for Disease Control and Prevention published the study Thursday.

The Michigan pediatrician who was the lead author says parents might think of melatonin as a vitamin, but she says it belongs in the medicine cabinet.

The popular over-the-counter sleep aid is sold in the U.S. as a supplement.

The study's authors said sales have increased by 150% between 2016-2020.

And since it's not regulated, the U.S. Food and Drug Administration doesn’t have oversight to know what ingredients are in it or how accurate the dosages are.