The endothelium is the lining of the blood vessels that helps prevent damage to the vessels. The endothelium does not function as well as it should in adolescents with type 1 diabetes. This causes future diabetes complications. Adolescents with diabetes also have abnormalities of the cells that repair the endothelium. These abnormalities may be due to damage caused by intermittent hyperglycemia. This studied is designed to study whether low dose, combined Vitamin C and E supplementation improves endothelial function and repair in adolescents with type 1 diabetes.

Inclusion Criteria:

1. Children and adolescent with T1D between 8 and 15 years of age will be studied.
2. Started on insulin therapy immediately after diagnosis.
3. Fasting c-peptide levels must be less than 0.4 ng/ml.
4. Hgb A1c levels greater than 8.3%.
5. All subjects must be in good health other than having diabetes. Subjects with hypothyroidism will be allowed assuming they are on stable thyroxine replacement and have normal thyroid function tests.
6. Females on oral contraceptives will also be eligible to participate.

Exclusion Criteria:

1. History oral hypoglycemic agent use.
2. BMI>95th percentile
3. Hypertension
4. Elevated creatinine levels
5. Microalbuminuria.