title: Does short-term vitamin C reduce cardiovascular risk in type 2 diabetes?
abstract: OBJECTIVE
  Vitamin C is a powerful antioxidant that is potentially useful in the prevention of atherosclerosis in diabetic individuals. However, the mechanism(s) of vitamin C's anti-atherosclerotic effects in vivo are unresolved, and clinical trials in nondiabetic individuals have yielded conflicting results. Therefore, we performed 32 studies in a randomized, crossover, dose-response trial in 8 volunteers with type 2 diabetes to determine the effects of vitamin C on serum vitamin C levels, lipids, inflammation, and coagulation.
  
  
  METHODS
  Well-controlled, type 2 volunteers received, in randomized order for 2-week periods, each of the following: 1) no supplemental vitamin C, 2) low-dose vitamin C (250 mg/day), 3) medium-dose vitamin C (500 mg/day), and 4) high-dose vitamin C (1,000 mg/day). A high-caloric content lunch was ingested during each study arm to enhance oxidative stress. Serum vitamin C levels and atherosclerotic risk factors including lipids and markers of oxidative stress, inflammation, and hypercoagulation were determined.
  
  
  RESULTS
  Serum vitamin C levels increased significantly at all dosages. In addition, the high-caloric content meal resulted in acute elevations of glucose, insulin, and triglycerides for several hours postmeal. However, no significant effect of vitamin C was observed on lipid parameters or any of the surrogate markers of oxidative stress, inflammation, or hypercoagulability.
  
  
  CONCLUSIONS
  Our study suggests that if vitamin C does have anti-atherosclerotic effects in diabetes, it does not exert them through the traditional pathways identifiable by established surrogate markers of cardiovascular risk.
authors.affiliation: University of Texas Health Sciences Center at Houston, Houston, Texas.
authors.forename: Absalon D
authors.initials: AD
authors.lastname: Gutierrez
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Duran-Valdez
authors.forename: Irina
authors.initials: I
authors.lastname: Robinson
authors.forename: Daniela Gonzalez
authors.initials: DG
authors.lastname: de Serna
authors.forename: David S
authors.initials: DS
authors.lastname: Schade
mesh_terms: D000328:Adult; D000975:Antioxidants / Q000627:therapeutic use*; D001205:Ascorbic Acid / Q000097:blood / Q000627:therapeutic use*; D001786:Blood Glucose / Q000187:drug effects; D002318:Cardiovascular Diseases / Q000517:prevention & control*; D003924:Diabetes Mellitus, Type 2 / Q000150:complications / Q000188:drug therapy*; D005260:Female; D006801:Humans; D007328:Insulin / Q000097:blood; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress / Q000187:drug effects; D012307:Risk Factors; D014280:Triglycerides / Q000097:blood
chemical_list: D000975:Antioxidants; D001786:Blood Glucose; D007328:Insulin; D014280:Triglycerides; D001205:Ascorbic Acid