We're told to get our vitamins—but there's a line when enough is enough, and when kids eat fortified breakfast cereal, they may be crossing that line, USA Today reports. "Millions of children are ingesting potentially unhealthy amounts" of three nutrients: vitamin A, zinc, and niacin, per a new report by the health research- and advocacy-minded Environmental Working Group. It found fortified cereal is the biggest source of excess, and says that's because the nutrients are packed in with adults' needs in mind—and labels list daily values set for adults in 1968. Just "a tiny, tiny percentage" of cereals show kids' daily values, says the group's director of research.
Per the report, some 10 million US kids get too much vitamin A; 13 million get too much zinc; and almost 5 million get too much niacin. While the three nutrients are necessary, too much vitamin A can eventually cause liver and skeletal problems, too much zinc can be bad for your immune function, and too much niacin can lead to rashes and vomiting. But a Kellogg's rep counters that kids need fortified cereals to get enough vitamins, and points out that of the 1,556 cereals EWG analyzed, only 23 had nutrient levels considered "much greater" than what kids 8 and under should eat—"and the vast majority of these are adult-oriented cereals not regularly consumed by children." Researchers say kids should only eat foods containing a max of 25% of the adult daily value of the nutrients in question. (Read more vitamins stories.)