Abstract
Objective: The scope of the diabetes epidemic stresses the critical need for primary prevention. The consumption of foods high in vitamin C has been associated with lower risk of diabetes. The aim of this study was to analyze the relation between vitamin C concentration and glycemic control index in a large sample of U.S. adults without a history of diabetes.
Methods: We analyzed data collected from 7697 adult participants in the National Health and Nutrition Examination Survey (NHANES) 2003–2006 who did not report a history of diabetes. Multivariate linear regression analyzed the association of vitamin C and hemoglobin A1c (A1c) levels after accounting for potential confounders. We also conducted stratified analyses based on race/ethnicity, gender, age group, body mass index, and vitamin D status.
Results: Vitamin C concentrations were inversely associated with A1c (p = 0.0202). Stronger inverse associations were observed in subjects 18–44 years of age (p = 0.0017), as well as in female (p = 0.0035) and Mexican American (p = 0.0149) subgroups. Evidence of a significant interaction between vitamin C and vitamin D was noted in subjects aged 18–44 years and in females (p = 0.0073 and 0.0095 respectively), with the inverse association tending to be evident at lower levels of vitamin D.
Conclusions: Vitamin C status may influence glycemic control. Investigators should be cognizant of the interaction of vitamins C and D and should take this into consideration in planning future studies.
ACKNOWLEDGEMENT
The authors would like to thank Dr. George Kuchel at the UConn Center on Aging for helpful comments on the manuscript.
Notes
V.L.F. was supported by in part by National Institutes of Health (NIH) Grant 5R01CA129140.