β-Cryptoxanthin from supplements or carotenoid-enhanced maize maintains liver vitamin A in Mongolian gerbils (Meriones unguiculatus) better than or equal to b-carotene supplements

Abstract

Maize with enhanced provitamin A carotenoids (biofortified), accomplished through conventional plant breeding, maintains vitamin A (VA) status in Mongolian gerbils (Meriones unguiculatus). Two studies in gerbils compared the VA value of β-cryptoxanthin with β-carotene. Study 1 (n 47) examined oil supplements and study 2 (n 46) used maize with enhanced β-cryptoxanthin and β-carotene. After 4 weeks' depletion, seven or six gerbils were killed; remaining gerbils were placed into weight-matched groups of 10. In study 1, daily supplements were cottonseed oil, and 35, 35 or 17.5 nmol VA (retinyl acetate), β-cryptoxanthin or β-carotene, respectively, for 3 weeks. In study 2, one group of gerbils was fed a 50% biofortified maize diet which contained 2.9 nmol β-cryptoxanthin and 3.2 nmol β-carotene/g feed. Other groups were given equivalent β-carotene or VA supplements based on prior-day intake from the biofortified maize or oil only for 4 weeks. In study 1, liver retinol was higher in the VA (0.74 (sd 0.11) μmol) and β-cryptoxanthin (0.65 (sd 0.10) μmol) groups than in the β-carotene (0.49 (sd0.13) μmol) and control (0.41 (sd 0.16) μmol) groups (P < 0.05). In study 2, the VA (1.17 (sd 0.19) μmol) and maize (0.71 (sd 0.18) μmol) groups had higher liver retinol than the control (0.42 (sd 0.16) μmol) group (P < 0.05), whereas the β-carotene (0.57 (sd 0.21) μmol) group did not. Bioconversion factors (i.e. 2.74 μg β-cryptoxanthin and 2.4 μg β-carotene equivalents in maize to 1μg retinol) were lower than the Institute of Medicine values. © The Authors 2008.