Serum vitamin C concentrations and diabetes: findings from the Third National Health and Nutrition Examination Survey, 1988-1994.
BACKGROUND
Previous studies suggested that diabetes mellitus may lower serum vitamin C concentrations, but most of these studies used clinic-based populations with established diabetes of varying duration and did not adjust for important covariates.


OBJECTIVE
Using a population-based sample and adjusting for important covariates, we asked whether serum vitamin C concentrations in persons with newly diagnosed diabetes differed from those in persons without diabetes.


METHODS
Data were obtained from the third National Health and Nutrition Examination Survey (1988-1994). Serum vitamin C was assayed by using reversed-phase HPLC with multiwavelength detection. Diabetes status (n = 237 persons with diabetes; n = 1803 persons without diabetes) was determined by oral-glucose-tolerance testing of the sample aged 40-74 y.


RESULTS
After adjustment for age and sex, mean serum vitamin C concentrations were significantly lower in persons with newly diagnosed diabetes than in those without diabetes. After adjustment for dietary intake of vitamin C and other important covariates, however, mean concentrations did not differ according to diabetes status.


CONCLUSIONS
When assessing serum vitamin C concentrations by diabetes status in the future, researchers should measure and account for all factors that influence serum vitamin C concentrations.
Division of Nutrition and Physical Activity, National Center for Chronic Disease Prevention and Health Promotion, Centers for Disease Control and Prevention, Atlanta, GA 30341, USA. jxw6@cdc.gov
J C
JC
Will
E S
ES
Ford
B A
BA
Bowman
D000328:Adult; D000368:Aged; D000375:Aging; D001205:Ascorbic Acid / Q000008:administration & dosage / Q000097:blood*; D001786:Blood Glucose / Q000378:metabolism; D003920:Diabetes Mellitus / Q000097:blood*; D004522:Educational Status; D015444:Exercise; D005260:Female; D006801:Humans; D007328:Insulin / Q000097:blood; D008297:Male; D008875:Middle Aged; D009749:Nutrition Surveys; D012907:Smoking
D001786:Blood Glucose; D007328:Insulin; D001205:Ascorbic Acid