Evaluating the impact of plant biofortification on human nutrition.

An evaluation of the efficacy of biofortified foods for improving human nutrition and health requires both laboratory- and community-based trials. A three-step process is proposed. First, tests of nutrient bioavailability should be conducted in the laboratory. Various genotypes of modified foods may be screened for bioavailability using in vitro cell-culture systems or experimental animals before testing in humans. Second, comprehensive feeding trials are conducted to test the efficacy of the biofortified food for improving the nutrition and health of target populations. These trials are generally done for several weeks or months, and they involve measuring a comprehensive set of endpoints. If efficacy is demonstrated in the feeding trial, the third step, a community-based trial, is planned. This final trial involves evaluating the nutritional, health, agricultural, societal, environmental and economic effects of the biofortified food in the community. A multidisciplinary team including consumers, policymakers, health leaders, as well as scientists is required for successful completion of the community trial.