Nutrient Requirements Twice the Amount of -Carotene Isolated from Carrots Is as Effective as -Carotene in Maintaining the Vitamin A Status of Mongolian Gerbils

The vitamin A (VA) value of carotenoids from fruits and vegetables is affected by many factors. This study determined the VA value of -carotene isolated from carrots compared with -carotene and retinyl acetate supplements fed to Mongolian gerbils (Meriones unguiculatus). Gerbils (n 38) were fed a VA-free diet for 4 wk. At baseline, 6 gerbils were killed to determine liver VA. Gerbils were divided into 3 treatment groups (n 9/group) and given 35, 35, or 17.5 nmol retinyl acetate, -carotene or -carotene, respectively, in 2 divided doses 5 h apart each day. The remaining 5 gerbils received oil vehicle. Gerbils were killed after 3 wk of supplementation. Serum samples and livers were collected and analyzed for VA. Liver extracts were subsequently saponified to quantify -retinol. Serum retinol concentrations did not differ among the groups. Liver retinyl palmitate concentrations were significantly higher in the retinyl acetate treatment group (0.198 0.051 mol/g; P 0.05) than in all other groups. The and -carotene treatments resulted in similar retinyl palmitate concentrations, i.e., 0.110 0.026 and 0.109 0.051 mol/g, respectively, which did not differ from the concentrations in gerbils killed at baseline (0.123 0.024 mol/g). The oil group had significantly less retinyl palmitate (0.061 0.029 mol/g; P 0.05) than all other groups. -Retinol was detected in livers of the -carotene group (0.062 0.013 mol/g). Thus, twice the amount of purified -carotene maintained VA status as well as -carotene in VA-depleted gerbils. Conversion factors were 5.5 g -carotene or 2.8 g -carotene to 1 g retinol. J. Nutr. 135: 2622–2626, 2005.