FOOD SAFETY: PDF OnlySafety Facets of Antioxidant SupplementsOmaye, Stanley T. PhD, F ATS Author Information Professor, Department of Nutrition & Environmental Sciences and Health, Graduate Program, University of Nevada, Reno, Reno, Nevada TOPICS IN CLINICAL NUTRITION 14(1):p 26-41, January 1999. Buy Abstract Like other chemical substances, antioxidants and other nutrients found in dietary supplements have the potential to produce adverse effects at high intakes. The relationship between health and the concentration of such chemical substances in the diet can be expressed graphically as an intake concentration (dose)-response/effect curve. Concentration-dependent effects are a continuum from lethal deficiencies to lethal excesses for antioxidant nutrients. Currently the safety of antioxidant supplements is described by the Dietary Supplement Health and Education Act of 1994 (DSHEA). Based on past performance, most supplements, including antioxidants, have been found to be generally safe, particularly up to 150% of the recommended dietary allowance (RDA). However, in the event of safety concerns, the proof rests with the Food and Drug Administration (FDA). Under certain situations, antioxidant substances can be prooxidants. Recent studies, both in vitro and in vivo, demonstrated the potential for ascorbic acid, α-tocopherol, and β-carotene to exhibit prooxidant effects which, in certain conditions, may contribute to adverse (toxic) effects. Thus vulnerable populations may be susceptible may be susceptible to adverse effects from antioxidant supplements above recommended levels. Increasing the intake of foods rich in ascorbic acid, α-tocopherol, and β-carotene is the most prudent way to obtain these antioxidants. © 1998 Aspen Publishers, Inc.