Liver injury from herbals and dietary supplements in the U.S. Drug-Induced Liver Injury Network

Approximately half the US adult population consumes herbals and dietary supplements (HDS),(1,2) with recent reports showing their use to be increasing.(3,4) Supplement users are more commonly women, non-Hispanic whites, over age 40, and have higher levels of education than non-users.(4-7) NHANES III data indicate that multivitamins and minerals are the most common supplements used, followed by calcium and fish oils.(5) However, the range of HDS is far broader and includes numerous commercial products. Although dietary supplements are perceived as safe (8), the current regulatory framework established by the Dietary Supplement Health and Education Act of 1994 (9) requires less evidence of safety prior to marketing as assessed by the Food and Drug Administration (FDA) than is required for pharmaceuticals. The FDA and other regulatory bodies can take action against a manufacturer only if there is proven adulteration or injury from its supplement. Recent cases of life-threatening hepatotoxicity from the dietary supplement OxyElite Pro (10) underscore the potential adverse consequences of this oversight process. The Drug-Induced Liver Injury Network (DILIN), supported by the National Institutes of Diabetes and Digestive and Kidney Diseases, was established in 2003 to identify, enroll, and characterize cases of drug-induced liver injury attributable to medications (excluding acetaminophen) and HDS (ClinicalTrials.gov Identifier:NCT00345930).(11) The original DILIN report identified HDS as the second most common cause for liver injury. (12) Since that report, many more cases have been accrued by the DILIN. Thus, we examined the burden and characteristics of liver injury attributable to HDS in the DILIN, and compared this injury with that due to conventional medications.