Federal health officials are seeking to clear up confusion about safety rules for dietary supplements by issuing draft guidelines for when manufacturers need to notify regulators about new ingredients, Reuters reported. The U.S. Food and Drug Administration (FDA) is seeking public comments on the document, which was issued July 2. Greater Des Moines is home to several supplement manufacturers, among them Kemin Industries Inc. The guidelines are intended to help companies comply with a 1994 law regulating new dietary ingredients in tablets, powders, liquids and other supplements. The law requires manufacturers to file a safety notification with the FDA before marketing dietary ingredients that were not on the market when the law passed. However, the FDA has only received about 700 notifications of new dietary ingredients in the past 16 years.