PURPOSE
Epidemiologic evidence regarding the role of dietary vitamin A in the development of diabetes is limited and inconsistent. This study was to explore the association between vitamin A intake and diabetes risk in Chinese adults.
METHODS
A prospective cohort study was conducted among 17,111 adults (8,537 men and 8,577 women) who participated in the China Health and Nutrition Survey (CHNS) during 1989-2015. Dietary intakes were assessed by three consecutive 24-hour dietary recalls combined with a household food inventory. Diabetes was determined by self-reported diagnosis, diabetes medication use or additional criterion in 2009 of fasting blood glucose or HbA1c. We analyzed the association of vitamin A intake (total, β-carotene, retinol) with diabetes risk using Cox proportional hazards models.
RESULTS
A total of 519 men and 531 women developed diabetes during a median of 11 years of follow-up. Higher dietary total vitamin A intakes were associated with a lower risk of diabetes in both men (Q5 vs Q1: HR=0.69, 95%CI: 0.49-0.97, P-trend=0.079) and women (Q5 vs Q1: HR=0.63, 95%CI: 0.45-0.89, P-trend=0.039). An inverse relation with diabetes risk was observed for dietary intakes of β-carotene (Q5 vs Q1: HR=0.71, 95%CI: 0.52-0.97) and retinol (Q5 vs Q1: HR=0.58, 95%CI: 0.39-0.85) among men, but not women. Dose-response analyses showed the association of dietary intakes of total vitamin A, β-carotene, and retinol with diabetes risk in men was L-shaped (P-nonlinearity=0.043), reverse J-shaped (P-nonlinearity=0.001), and linear, respectively.
CONCLUSION
Our findings suggest that adequate intake of vitamin A may help protecting against diabetes, especially for men.