(Reuters) - Significant levels of arsenic may be found in some prepared food products listing organic brown rice syrup as a sweetener and main ingredient, including some cereal bars and infant formulas, according to findings from a study published on Thursday.

Higher concentrations of inorganic arsenic found in certain infant formulas, some cereal bars and high energy foods prompted Dartmouth College researchers conducting the analysis to call for regulatory limits on arsenic levels in food.

According to the study, one of the two infant formulas tested with organic brown rice syrup as the primary ingredient had arsenic concentrations up to six times the federal safe drinking water limit.

Results showed the cereal bars and energy foods used by endurance athletes that contained organic brown rice syrup also had higher arsenic concentrations than comparable food products without the sweetener.

Organic brown rice syrup is used as a sweetener in some food products as an alternative to high fructose corn syrup, researchers said, and rice can be a major source of inorganic arsenic.

The study, "Arsenic, Organic Foods, and Brown Rice Syrup" was released online in Environmental Health Perspectives, a journal published by the National Institute of Environmental Health Sciences.

The Dartmouth College researchers tested 17 infant formulas, 29 cereal bars and three energy shots that were purchased in the Hanover, New Hampshire area.

The Dartmouth study follows a report last year analyzing arsenic levels in some fruit juices that showed samples exceeding federal limits in place for drinking water and prompted concern from consumer groups.

Juice producers said they were confident the juice being sold is safe for kids.

(Reporting By Lauren Keiper; Editing by Daniel Trotta)

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