Retinoic acid (RA) is the most biologically active metabolite of vitamin A and is important for stomach physiological function. However, little is known about the metabolic status of RA in human gastric lesions. From 2015 to 2018, 1,392 local residents in Lujiang County were recruited into a cross-sectional survey program, which included a questionnaire interview and blood collection. We detected the mRNA and protein expression of RA metabolism-relevant factors in gastric tissues from 68 local patients with gastric lesions. The effects of all-trans retinoic acid (ATRA) supplementation were investigated in a gastric precancerous lesions (GPLs) rat model. In the cross-sectional survey, no significant differences in the level of RA precursor (