Duration

Findings

5–12 d

↓ In vivo nitrosation (N-nitrosoproline)

1 wk

↓ Urinary β-glucuronidase activity (linked to bladder cancer)

4 wk

↓ Gastric mucosa DNAa adduct formation

4 wk

O6-alkyltransferase DNA repair enzyme

Significant (p < .001) correlation between gastric mucosa ascorbyl radical concentration and ROSb activity

4–12 mo

↓ Nitrotyrosine in gastric mucosa (measure of RNSc activity)

1 d

↓ In vivo nitrosation by urinary nitrosoproline products

Vitamin C Dose

Findings

18 mg/min (infusion)

↑ Forearm blood flow 1.6-fold (measured after acetylcholine infusion)

2,000 mg (oral)

↑ Brachial artery dilation 3.2-fold (measured after 2 h)

24 mg/min (infusion)

↑ Forearm blood flow 1.4-fold (measured after methacholine infusion)

10 mg/min (infusion)

↑ Brachial artery dilation 1.7-fold (measured after 20 min)

3,000 mg (infusion)

↓ Coronary artery vasoconstriction 2.6-fold (measured after acetylcholine infusion)

24 mg/min (infusion)

↑ Forearm blood flow 1.3-fold (measured after methacholine infusion)

25 mg/min (infusion)

↑ Radial artery dilation 1.6-fold (measured after 10 min)

2,000 mg (oral)

↑ Radial artery dilation 1.5-fold (following 4 wk supplementation)

2.4 mg/min (infusion)

↑ Forearm blood flow 1.3-fold (acetycholine)

24 mg/min (infusion)

↑ Forearm blood flow 1.4-fold (measured after methacholine infusion)



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