Bioaccumulated provitamin A in black soldier fly larvae is bioavailable and capable of improving vitamin A status of gerbils

Abstract

The aim was to study whether provitamin A (proVA), which can bioaccumulate in black soldier fly larvae (BSFL), is bioavailable and can restore VA status in mammals. A model for studying the metabolism of this vitamin, the gerbil, was either fed a standard diet (C+ group), a diet without VA (C-), a diet in which VA was provided by β-carotene (β-C) from sweet potatoes (SP), or a diet in which VA was provided by β-C from BSFL that had been fed sweet potatoes (BSFL). The animals were killed at the end of the supplementation period and β-C, retinol and retinyl esters were measured in plasma and liver. As expected β-C was not detected in plasma and liver of the C+ and C- groups. β-C concentrations were lower (p < 0.05) in plasma and liver of the BSFL group as compared to the SP group. Liver retinol and retinyl ester concentrations were lower in the C- group than in all the other groups (p < 0.05). These concentrations were not significantly different in the C+ and SP groups while they were lower in the BSFL group (p < 0.05 for retinyl oleate and retinyl linoleate). In total, the liver stock of retinol equivalent was almost twice lower in the BSFL group than in the SP group. Thus, β-C present in the BSFL matrix is bioavailable and capable of improving VA status, but this matrix decreases its effectiveness by a factor of around two compared to the sweet potato matrix.