Phase 2 Study of VITAMIN A EQUIVALENCE OF PLANT CAROTENOIDS IN CHILDREN

This project is to determine the vitamin A value (equivalence) of dietary provitamin A carotenes from spinach, Golden Rice, and pure ß-carotene (ß-C) in oil. These experiments will be conducted in children (ages 6-8) with/without adequate (marginal deficiency) vitamin A nutrition. As plant provitamin A carotenoids are a major and safe vitamin A source for a vast population in the world, it is essential to determine the efficiency of provitamin A carotenoid (mainly ß-C) conversion to vitamin A. By introducing ß-C into rice endosperm, Golden Rice may directly benefit consumers by providing vitamin A nutrition. Our investigation uses hydroponically grown, deca-deuterium labeled spinach and Golden Rice, synthetic ß-C-d10 and a vitamin A isotope reference, C13 labeled retinyl acetate (13C10-RAc), to evaluate the bioavailability and the bioconversion of plant provitamin A carotenes to retinol as compared with ß-C in oil capsules in vivo.

Seventy-two children each will take two meals, breakfast containing 13C10-RAc dose (0.5mg in 0.2g oil capsule) and lunch containing spinach containing 1 mg ß-C (along with white rice), or Golden Rice containing 0.5mg ß-C (along with light colored vegetables), or ß-C oil capsules containing 0.5 mg ß-C in 0.2g oil (along with white rice and light colored vegetables) on the first day of the study. Blood samples will be collected at 1 3, 7, 14, and 21 days after the study doses.

The enrichment of labeled ß-C and labeled retinol in human circulation will be determined using advanced liquid chromatography / mass spectrometry and gas chromatography / mass spectrometry. Through the applications of these novel technologies, we will be able to determine the relative biological activities of endogenous carotenoids; that is, the vitamin A value of spinach, Golden Rice, and ß-C in oil capsules for children with/without vitamin A malnutrition.

This study will be of importance in planning vitamin A deficiency prevention strategies and also will provide useful information regarding the potential efficacy of a bioengineered crop to provide vitamin A nutrition.