BCO1 and metabolic dysfunction-associated steatotic liver disease: Additionally, retinoids have been reported to be useful as a therapeutic agent for NAFLD, but their overconsumption can cause adverse effects, while provitamin A molecules such as β-cryptoxanthin do not cause adverse effects and are known to serve as a supply source of retinoids through metabolic conversion by BCMO1 only when retinoids are deficient in the body.