all-trans-retinol + AH2 => all-trans-7,8-dihydroretinol + A
all-trans-retinol + ah2 => all-trans-7,8-dihydroretinol + a
all-trans-retinol + AH2 => all-trans-7,8-dihydroretinol + A
all-trans-retinol + ah2 => all-trans-7,8-dihydroretinol + a