Comparing the vitamin A bioefficacy of β‐cryptoxanthin to β‐carotene from supplements and maize in Mongolian gerbils

Abstract

Maize biofortified with provitamin A carotenoids maintains vitamin A (VA) status in Mongolian gerbils. β-Cryptoxanthin (βCX) contributes to VA, but the VA equivalency factor of βCX is unknown. Two studies were performed in gerbils to compare the bioefficacy of βCX to that of β-carotene (βC). Study 1 (n = 47) examined the VA value of oil supplements and study 2 (n = 57) used biofortified maize with varying levels of βCX. Gerbils were fed VA-free diets (45% white maize) for 4 wk. Seven gerbils were killed at baseline. Remaining gerbils were placed into weight-matched groups of 10. In study 1, treatments were oil control, or 35, 35, or 17.5 nmol VA (retinyl acetate), βCX, or βC, respectively. Blood and livers were collected at 3 wk. In study 2, 3 groups were fed diets with 45% maize which were mixed to contain 5.9 nmol VA/g feed assuming 100% bioefficacy. The diets had 0.30, 1.05, or 2.13 nmol βCX/g feed. Controls received either equivalent VA or oil only. Livers and serum were collected at 4 wk. In study 1, liver VA was higher in the VA (0.69 ± 0.11 μmol) and βCX (0.60 ± 0.10 μmol) groups than in the βC (0.49 ± 0.13 μmol) and control (0.37 ± 0.15 μmol) groups (P < 0.05). Study 2 will further evaluate the provitamin A value of βCX from maize. βCX contributes significant VA to the gerbil. Biofortified maize should be promoted in countries that consume maize as a staple food to enhance VA status. Supported by HarvestPlus, Hatch WIS04975 and USAID.