Golden Rice is a genetically modified plant developed to contain more beta-carotene in the grains, seen as a viable method of alleviating vitamin-A deficiency particularly in developing countries. In its current form, Golden Rice contains 35 micrograms of beta-carotene per gram. But how much of these are actually absorbed by the body?
According to a newly published clinical study, four units of beta-carotene from Golden Rice convert to one unit of vitamin A in humans.
Our results showed that the mean (±SD) area under the curve for the total serum response to [2H]retinol was 39.9 ± 20.7 µg·d after the Golden Rice dose. Compared with that of the [13C10]retinyl acetate reference dose (84.7 ± 34.6 µg·d), Golden Rice β-carotene provided 0.24-0.94 mg retinol. Thus, the conversion factor of Golden Rice β-carotene to retinol is 3.8 ± 1.7 to 1 with a range of 1.9-6.4 to 1 by weight, or 2.0 ± 0.9 to 1 with a range of 1.0-3.4 to by moles.
They conclude that the Golden rice is effectively converted to vitamin A in humans.