BackgroundNon-alcoholic fatty liver disease (NAFLD) is described by the abnormal accumulation of fats in livers of individuals without significant alcohol intake. It includes a spectrum of diseases from simple steatosis to steatohepatitis (NASH) with fibrosis and cirrhosis. The prevalence of NAFLD is rising in association with increasing obesity worldwide. Retinoic acid (RA), a metabolite of vitamin A, mediates the functions of vitamin A required for growth and development. Also, RA has been shown to reduce adiposity not only in fat cells but also in the liver through increasing triglyceride hydrolysis and fat oxidation. This could put a future trial of preventing NASH and cirrhosis development by vitamin A supplementation. This work aimed to study the role of retinoic acid in NAFLD, whether it can differentiate simple steatosis from NASH and correlate the result with the NAFLD fibrosis score. It is a cross-sectional study done on 180 patients divided into three groups. Group 1 is composed of 80 patients with simple steatosis and normal ALT; group 2 is composed of 80 patients with NASH and high ALT in addition to group 3 with 20 healthy subjects served as a control group. All patients were proven to have fatty liver by ultrasonography. Serum RA was assayed by using enzyme-linked immunosorbent assay (ELISA) technique, and the NAFLD fibrosis score was calculated and compared with the retinoic acid level.ResultSerum RA level was significantly decreased in the patient groups as compared to the controls; the lowest serum level was observed among the NASH group, followed by the steatosis group. NAFLD fibrosis score was calculated, and it was higher in the NASH group than in the steatosis group. Besides, there was a significant negative correlation between retinoic acid and NAFLD score among the patient groups.ConclusionSerum RA level was lower in patients with simple steatosis and NASH. RA had a high statistically significant difference in differentiation between the patient groups and the control group. The results were comparable to the NAFLD fibrosis score. Thus, retinoic acid could be used for diagnosis and accessing the degree of NAFLD.