Alcohol and aldehyde dehydrogenases: Retinoid metabolic effects in mouse knockout models

► This review focuses on the enzymes that convert vitamin A (retinol) to retinoic acid. ► Alcohol dehydrogenases and retinol dehydrogenases convert retinol to retinaldehyde. ► Retinaldehyde dehydrogenases metabolize retinaldehyde to retinoic acid. ► We discuss mouse models carrying loss-of-function mutations for these enzymes. ► These mouse models have been instrumental for understanding vitamin A function.