Bioavailability of Golden Rice Carotenoids in Humans

• The enrichment of labeled golden rice β-carotene and its conversion to labeled retinol in serum samples after the golden rice meal with 0, 5, or 10 g fat (butter) as compared to the reference dose of vitamin A that is labeled differently. [ Time Frame: 33 days ] [ Designated as safety issue: No ]
  

Recently, scientists have genetically engineered "golden rice" that contains 1.6 ug ß-carotene in a gram of dry rice (12). Since the vitamin A equivalency varies from 2 ug (oil dose) to 27 ug (vegetable) carotene to 1 retinol equivalent and the equivalency is matrix dependent, it is necessary to know what the vitamin A equivalency of golden rice beta-carotene is. The determination of the absorption and conversion of golden rice beta-carotene is of importance for designing food programs in many rice-eating regions of the world, where vitamin A deficiency is common.

To evaluate the absorption and intestinal conversion of rice beta-carotene after an acute dose of golden rice, an intrinsically labeled Golden Rice with a labeled reference dose of vitamin A are used. We propose to conduct a pilot study on the US adults with normal vitamin A status (n = 15).

The specific aims of this pilot study are:

1. To determine ß-carotene response kinetics following a meal of golden rice with 0, 5, or 10 g fat (butter);
2. To determine retinol kinetics from the golden rice and from the labeled vitamin A dose;
3. To determine vitamin A value of golden rice ß-carotene in adults with normal vitamin A status. The determination of the absorption and conversion of golden rice ß-carotene is of importance for designing food programs in many rice-eating regions of the world, where vitamin A deficiency is common.