Plants for human health: Stable isotope approaches to assess the vitamin A value of biofortified Golden Rice and high beta-carotene maize

Authors: Grusak, Michael

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 1/12/2011
Publication Date: 3/3/2011
Citation: Grusak, M.A. 2011. Plants for human health: Stable isotope approaches to assess the vitamin A value of biofortified Golden Rice and high beta-carotene maize [abstract]. Texas Academy of Sciences 114th Annual Meeting. p. 54.

Interpretive Summary:

Technical Abstract: Vitamin A deficiency is a major public health problem, especially in populations of the developing world where staple foods, such as rice, wheat, and maize, make up a significant portion of daily caloric intake. Seeds of these crops contain little to no provitamin A carotenoids (e.g., beta-carotene, a precursor of vitamin A); thus, the consumption of diets focused on these foods, in combination with limited intake of colored fruit, vegetables, or animal products, leads to sub-optimal vitamin A status in humans. To combat this problem, plant scientists have used various strategies to develop biofortified food crops. These are new crop cultivars with the ability to accumulate or synthesize higher concentrations of nutrients or nutrient precursors (relative to existing cultivars). The transgenic Golden Rice and conventionally bred high beta-carotene maize are two such product lines. In order to assess their nutritional value, and to determine their potential for alleviating vitamin A deficiency, we have used stable isotope approaches to label beta-carotene in seeds, using deuterium, a heavy isotope of hydrogen. Labeled food products have been fed to human subjects and blood samples have been collected, which allowed us to monitor the absorption of beta-carotene and determine its conversion efficiency to vitamin A. Our methods development will be discussed to describe the possibilities and problems encountered when attempting to label plants with heavy water (deuterium oxide). Results of the clinical trials will be presented to demonstrate that both Golden Rice and high beta-carotene maize can serve as effective sources of vitamin A.