This study is an open-label pilot designed to examine the dose-dependent effects of erythritol, a zero calorie sweetener, on endothelial function. Twenty-four subjects with type 2 diabetes mellitus will make three study visits. At each visit, the will consume an orange-flavored beverage containing escalating amounts of erythritol (6, 12, and 18 grams). Endothelial function will be assessed before and two hours after beverage consumption. Endothelial function will be measured as the change in pulse amplitude in response to reactive hyperemia measured in the fingertip by peripheral arterial tonometry. The results will be used to plan a randomized, placebo-controlled study.

Inclusion Criteria:

• Male and Female subjects
• Otherwise healthy patients with Type 2 diabetes mellitus as defined by fasting blood glucose >125 mg/dl or with ongoing treatment for Type 2 diabetes mellitus with the exception of insulin.

Exclusion Criteria:

• Women with a positive urine pregnancy test
• Body mass index >35 kg/m2
• Current daily long-acting insulin therapy (short acting, insulin as needed is not an exclusion).
• Clinical history of other major illness including cancer, renal failure, hepatic failure, or other conditions that in the judgment of the principal investigator make a clinical study inappropriate.
• Treatment with an investigational drug within the last twelve weeks
• History of a psychological illness or condition such as to interfere with the subject's ability to understand the requirements of the study.
• Treatment with vitamin E, vitamin C, and beta carotene, lipoic acid, and other food or herbal supplements within 1 month of enrollment. Subjects taking multivitamins or other forms of vitamin E and C in doses that do not exceed two times the recommended daily allowance will not be excluded.
• Recent change in diet or level of physical activity that in the judgment of the investigators would be likely to affect endothelial function (to be evaluated on a case by case basis).
• Ongoing illicit drug use or alcohol abuse.
• Sensitivity/intolerance to dietary polyols.