June 25, 2014 -- The glut of food products -- namely breakfast cereals and snack bars -- pumped up with vitamins and minerals puts children and pregnant women at risk for eating too much of a good thing, concludes a report out Tuesday.
But a leading nutrition scientist calls the report “worrisome” and says fortified foods can play a role in proper nutrition.
The report, from the Environmental Working Group (EWG), says nearly half of U.S. children age 8 and younger ingest potentially harmful amounts of vitamin A, zinc, and niacin because of excessive food fortification, along with vitamin supplements. The EWG is a national environmental health research and advocacy organization.
Over time, regularly getting too much vitamin A from foods or supplements can lead to liver damage, bone abnormalities, peeling skin, brittle nails, and hair loss, the report’s authors write. And too much vitamin A during pregnancy can result in abnormalities in the fetus, the report says. (Eating foods naturally high in vitamin A, such as carrots or pumpkin, is considered safe.)
According to the report, “It is difficult or impossible to link these nutrient overexposures to specific cases of harm to children’s health," but several studies show that fortified food, when taken with supplements (such as gummy vitamins), over time could put children at risk for potential bad effects.
“We’re not trying to raise a huge alarm,” coauthor Renee Sharp, EWG research director, tells WebMD. However, she says, “parents should exercise caution when it comes to products with more than 20% or 25% of the daily value for vitamin A and niacin.”
Fortification of certain foods with specific nutrients is required in the U.S. For example, enriched cereal grain products must be fortified with folic acid. But manufacturers choose to fortify many other products, a move designed to raise their health cachet, the EWG report says.
Simply looking at nutrition labels on foods isn’t enough of a safeguard against getting too many vitamins and minerals, Sharp says, because the listed “Daily Values” were determined in an era when vitamin deficiencies were a greater concern. Also, few products provide nutritional information for children as well as adults, she says.
“It’s a fact that the daily values were set in 1968 and they’re out of date. It’s a fact that they’re for adults and not for children. It’s a fact that since the daily values were set decades ago, there have been huge changes in our food supply,” Sharp says.
Kris Charles, a spokesperson for Kellogg Company, a leading breakfast cereal manufacturer, says in a statement that the company “is concerned that the EWG report could needlessly alarm parents looking to make the right nutrition choices for their children. The report ignores a great deal of the nutrition science and consumption data showing that without fortification of foods such as ready-to-eat cereals, many children would not get enough vitamins and minerals in their diets.”
Louise Berner, PhD, whose research is cited in the EWG report, also questions its conclusions.
“I agree that excessive or indiscriminate fortification, particularly along with the indiscriminate or unneeded use of supplements, is a potential issue of concern, but the EWG report is worrisome to me in several respects,” Berner, a professor of food science and nutrition at Cal Poly State University in San Luis Obispo, CA, tells WebMD.
One problem, she says, is that the report fails to mention uncertainty surrounding the “tolerable upper intake level,” or UL, the highest level of daily nutrient intake likely to pose no risk of harm. The UL is the cutoff the report uses when it makes such statements as “45% of 2- to 8-year-old children consume too much zinc.”
But researchers have widely noted that the UL values are too low for some nutrients, such as zinc, Berner says. The UL values for children should be revisited, she says. Also, Berner says, the report “selects data and summarizes findings out of context.”
And finally, she says, the report “mischaracterizes the main message of our published data as I interpret them.” She says her research shows that fortified foods, mainly enriched grains, breakfast cereals, milk and juice, play an important role in ensuring that children get adequate amounts of many nutrients. Supplement use, and not fortification, seems to be “the major driver of potentially high [nutrient] intakes,” Berner says.