Golden Rice is an effective source of vitamin A.

BACKGROUND Genetically engineered "Golden Rice" contains up to 35 microg beta-carotene per gram of rice. It is important to determine the vitamin A equivalency of Golden Rice beta-carotene to project the potential effect of this biofortified grain in rice-consuming populations that commonly exhibit low vitamin A status. OBJECTIVE The objective was to determine the vitamin A value of intrinsically labeled dietary Golden Rice in humans. DESIGN Golden Rice plants were grown hydroponically with heavy water (deuterium oxide) to generate deuterium-labeled [2H]beta-carotene in the rice grains. Golden Rice servings of 65-98 g (130-200 g cooked rice) containing 0.99-1.53 mg beta-carotene were fed to 5 healthy adult volunteers (3 women and 2 men) with 10 g butter. A reference dose of [13C10]retinyl acetate (0.4-1.0 mg) in oil was given to each volunteer 1 wk before ingestion of the Golden Rice dose. Blood samples were collected over 36 d. RESULTS Our results showed that the mean (+/-SD) area under the curve for the total serum response to [2H]retinol was 39.9 +/- 20.7 microg x d after the Golden Rice dose. Compared with that of the [13C10]retinyl acetate reference dose (84.7 +/- 34.6 microg x d), Golden Rice beta-carotene provided 0.24-0.94 mg retinol. Thus, the conversion factor of Golden Rice beta-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 1 by moles. CONCLUSION Beta-carotene derived from Golden Rice is effectively converted to vitamin A in humans. This trial was registered at clinicaltrials.gov as NCT00680355.

[1]  Alexander J. Stein,et al.  Genetic Engineering for the Poor: Golden Rice and Public Health in India , 2008 .

[2]  P. Trumbo,et al.  Dietary reference intakes: vitamin A, vitamin K, arsenic, boron, chromium, copper, iodine, iron, manganese, molybdenum, nickel, silicon, vanadium, and zinc. , 1998, Journal of the American Dietetic Association.

[3]  P. Arthur,et al.  The contribution of vitamin A to public health , 1996, FASEB journal : official publication of the Federation of American Societies for Experimental Biology.

[4]  A. Sommer.  Nutritional Blindness: Xerophthalmia and Keratomalacia , 1982 .

[5]  K. Jamil,et al.  Daily consumption of Indian spinach (Basella alba) or sweet potatoes has a positive effect on total-body vitamin A stores in Bangladeshi men. , 2004, The American journal of clinical nutrition.

[6]  J. Katz,et al.  Efficacy of vitamin A in reducing preschool child mortality in Nepal , 1991, The Lancet.

[7]  M. Grusak.  Intrinsic stable isotope labeling of plants for nutritional investigations in humans , 1997 .

[8]  G. Dolnikowski,et al.  Deuterium enrichment of retinol in humans determined by gas chromatography electron capture negative chemical ionization mass spectrometry , 1998 .

[9]  R. Russell,et al.  Atmospheric pressure chemical ionization and electron capture negative chemical ionization mass spectrometry in studying beta-carotene conversion to retinol in humans. , 1997, Methods in enzymology.

[10]  E. Hinchliffe,et al.  Improving the nutritional value of Golden Rice through increased pro-vitamin A content , 2005, Nature Biotechnology.

[11]  I. Darnton-Hill,et al.  Vitamin A Deficiency , 2001 .

[12]  Michael A Grusak,et al.  Spinach or carrots can supply significant amounts of vitamin A as assessed by feeding with intrinsically deuterated vegetables. , 2005, The American journal of clinical nutrition.

[13]  J. Hautvast,et al.  The contribution of plant foods to the vitamin A supply of lactating women in Vietnam: a randomized controlled trial. , 2007, The American journal of clinical nutrition.

[14]  Organización Mundial de la Salud.  Global prevalence of vitamin A deficiency , 1995 .

[15]  D. Karyadi,et al.  Lack of improvement in vitamin A status with increased consumption of dark-green leafy vegetables , 1995, The Lancet.

[16]  A. Giuliano,et al.  Plasma response of children to short-term chronic beta-carotene supplementation. , 1994, The American journal of clinical nutrition.

[17]  Joint Fao Who Expert Consultation on Human Vitamin and M Requirements.  Vitamin and mineral requirements in human nutrition , 2005 .

[18]  P. Nestel,et al.  Stable isotope dilution techniques for assessing vitamin A status and bioefficacy of provitamin A carotenoids in humans , 2005, Public Health Nutrition.

[19]  R. Russell,et al.  Serum carotenoids and retinoids in ferrets fed canthaxanthin , 1993 .

[20]  J. Hautvast,et al.  Orange fruit is more effective than are dark-green, leafy vegetables in increasing serum concentrations of retinol and beta-carotene in schoolchildren in Indonesia. , 1998, The American journal of clinical nutrition.

[21]  R. Russell,et al.  Use of the deuterated-retinol-dilution technique to monitor the vitamin A status of Nicaraguan schoolchildren 1 y after initiation of the Nicaraguan national program of sugar fortification with vitamin A. , 2004, The American journal of clinical nutrition.

[22]  R. Russell,et al.  Green and yellow vegetables can maintain body stores of vitamin A in Chinese children. , 1999, The American journal of clinical nutrition.

[23]  A. Ross,et al.  Vitamin A and retinoids in antiviral responses , 1996, FASEB journal : official publication of the Federation of American Societies for Experimental Biology.

[24]  R. Russell,et al.  Vitamin A equivalence of spirulina beta-carotene in Chinese adults as assessed by using a stable-isotope reference method. , 2008, The American journal of clinical nutrition.

[25]  A. Sommer,et al.  Vitamin A Deficiency: Health, Survival, and Vision , 1996 .

[26]  S. Booth,et al.  Human plasma carotenoid response to the ingestion of controlled diets high in fruits and vegetables. , 1996, The American journal of clinical nutrition.

[27]  Jing Zhang,et al.  Engineering the Provitamin A (b-Carotene) Biosynthetic Pathway into (Carotenoid-Free) , 2000 .