The purpose of this study is to compare levels of vitamin C in the blood over the 24 hour period following a single 1000 mg dose of vitamin C from ascorbic acid, calcium ascorbate and placebo.

Inclusion Criteria:

• Healthy as determined by laboratory results and medical history
• Females not of child bearing potential
• BMI 18-30 kg/m2
• Agrees to consume a low vitamin C diet
• Non-smoker or ex-smoker >1 year

Exclusion Criteria:

• Pregnant, breastfeeding, or planning to become pregnant during the trial
• Alcohol >2 drinks per day; alcohol or drug abuse within the past year
• Cardiac conditions
• Duodenal ulcer or gastric ulcer, gastritis, hiatus hernia, or gastroesophageal reflux disease (GERD) within past 3 months
• History irritable bowel syndrome, malabsorption or significant GI disease
• History of kidney stones
• Use of medications known to interact with vitamin C
• Use of supplements containing vitamin C
• Use of anticoagulants (warfarin), barbiturates, tetracycline antibiotics, beta-blockers, cyclosporine, prednisone, tricyclic antidepressants, diuretics and nitrate medications
• History of or current diagnosis of cancer
• Uncontrolled hypertension
• History of diabetes, renal disease and/or liver disease
• Unstable psychiatric disorder
• History of or current immunocompromise
• History of hemochromatosis or hemoglobinopathies
• Participation in a clinical research trial <30 days
• Use of acute medication w/in 72 hours of intervention
• Unstable medications <90 days
• Abnormal liver function
• Serum creatinine > 1.5 x upper limit of normal (ULN)
• Anemia of any etiology
• Blood donation w/in the last 2 months
• Allergy or sensitivity to test articles, foods or beverages provided during the study
• Cognitive impairment and/or unable to give informed consent