1. Copyright © 1999 American Medical Association. All rights reserved.
From: Criteria and Recommendations for Vitamin C Intake
JAMA. 1999;281(15): doi: /jama
Figure Legend:
Oxidation of vitamin C (L-ascorbic acid) sequentiallyreleases 2 donor electrons that become available for biochemicalreactions observed in vivo and/or in vitro. In the molecular diagrams,carbon atoms are black; oxygen, red; and hydrogen, white. Up and downarrows mean an increase or decrease in level.
Date of download: 10/9/2017
Copyright © 1999 American Medical Association. All rights reserved.

2. Copyright © 1999 American Medical Association. All rights reserved.
From: Criteria and Recommendations for Vitamin C Intake
JAMA. 1999;281(15): doi: /jama
Figure Legend:
Subjects ingested less than 5 mg of vitamin C daily from dietarysources. When subjects' vitamin C plasma concentrations decreased toapproximately 7 µmol/L, each of 7 repletion doses were administeredin succession. Doses of 15 to 1250 mg were administered twice daily.Subjects achieved steady-state for each dose before the next dose wasadministered. Data represent fasting morning samples. Plateauconcentration was defined as the mean of 5 or more samples drawn overat least 7 days with 10% SD or less. The first sample included in allplateau determinations was 90% or more of the final plateau mean. Usedwith permission from the Proceedings of the National Academy ofSciences.
Date of download: 10/9/2017
Copyright © 1999 American Medical Association. All rights reserved.

3. Copyright © 1999 American Medical Association. All rights reserved.
From: Criteria and Recommendations for Vitamin C Intake
JAMA. 1999;281(15): doi: /jama
Figure Legend:
Bioavailability is shown for 1 subject at 200 mg (top) and at 1250mg (bottom). For each dose, vitamin C was administered at zero time (8AM) orally and samples were obtained as shown. After 24hours the same dose was given intravenously and samples were obtainedas shown. Dashed lines indicate baselines. Bioavailability sampling wasperformed at steady-state for the total daily dose. Bioavailability wasthe ratio of the area of the oral dose (area under thecurvepo) divided by the area of the intravenous dose (areaunder the curveiv). See "Bioavailability" for details.Used with permission from the Proceedings of the National Academy ofSciences.
Date of download: 10/9/2017
Copyright © 1999 American Medical Association. All rights reserved.