• INCLUSION CRITERIA:

We propose to study 150 male and female subjects between the ages of 18 and 65. This will include 50 healthy subjects and 100 subjects with type 1 or type 2 diabetes. To be included in the study, study subjects should:

• Be non smokers and be in good general health.
• Have no significant illnesses other than the complications of diabetes mellitus but should not have neuropathy affecting the functioning of internal organs such as the stomach and urinary bladder.
• Have serum creatinine less than 2.
• Be normotensive at the time of the study, with a blood pressure less than or equal to 140/90.

Acceptable medications include insulin and ACE inhibitors or ARBs for type 1 diabetes and oral hypoglycemic agents and ACE inhibitors or ARBs in the case of type 2 diabetes. Type 1 and type 2 diabetic subjects on aspirin are also eligible provided they are not taking it for known ischemic heart disease or cerebrovascular disease. The aim of this study is to determine whether diabetic subjects lose vitamin C in the urine in their normal clinical condition (i.e while on treatment) and not in the native untreated state of uncontrolled hyperglycemia. Therefore the patients will not discontinue medication.

EXCLUSION CRITERIA:

Exclusion criteria will include the following:

• Significant organ malfunction including liver disease, pulmonary disease, ischemic heart disease, heart failure, stroke, peripheral vascular disease, and anemia.
• Other serious or chronic illness; history of serious or chronic illness; coronary artery disease, or peripheral vascular disease.
• Pregnancy or acromegaly.
• Alcohol abuse, drug addiction or the use of illegal drugs.
• Use of vitamin supplements within 2 weeks prior to sample procurement.
• Positive HIV or hepatitis (B or C) screening tests (subjects will be notified of these test results).
• Presence of other concomitant conditions which in the judgment of the investigators can influence vitamin C metabolism or vitamin C renal handling.

For inpatient subjects, an additional exclusion criterion is consumption during the hospitalization of any foods or beverages other than those in the vitamin C free diet.