Association between Peripheral Leukocyte Telomere Length and Dietary Vitamin A and Carotenoid in U.S. Adults

To investigate the independent association between peripheral leukocyte telomere length and dietary vitamin A and carotenoid, we collected 839 participants older than 20-year from the 1999-2000 National Health and Nutrition Examination Survey. The peripheral leukocyte telomere length was obtained using the quantitative polymerase chain reaction method. Dietary information, such as alcohol, caffeine, carotenoid, folate and vitamin A/B1/B2/B6/B12/C/E was from a recall of the previous 24h taken food. Multivariable logistic regression and smooth curve fitting was conducted to analyze the independent association between telomere length and dietary vitamin A and carotenoid. Obesity was further treated as effect modification factor in the stratified analysis. After adjusting for age, race, sex, education, obesity, physical activity, PIR, smoking status, CAD history, serum concentrations of vitamin E/A/B12, folate, gamma-tocopherol, CRP, total cholesterol, cadmium and dietary intake of alcohol, caffeine, fiber, folate and vitamin B1/B2/B6/B12/C/E, the daily vitamin A and carotenoid intake was not significantly associated with telomere length in general population (vitamin A: 0.0009, 95% CI: -0.0041, 0.0058; carotenoid: 0.0040, 95% CI: -0.0458, 0.0538). In non-obesity population, the association coefficient was -0.0121 (95% CI: -0.0259, 0.0017) for vitamin A and -0.1369 (95% CI: -0.2809, 0.0070) for carotenoid. Vitamin A and carotenoid consumption was not associated with peripheral leukocyte telomere length independently in general adult population. However, in non-obese individuals, increasing vitamin A and carotenoid might tend to associate with decreasing peripheral leukocyte telomere length.