Recommended Daily Dosage for Vitamin C
For healthy adults, the recommended daily intake of vitamin C is 90 mg for men and 75 mg for women, based on the most recent U.S. guidelines, though European authorities recommend higher amounts of 110 mg for men and 95 mg for women. 1
Standard Recommendations by Region
The global recommendations vary significantly based on different health perspectives:
- United States/Canada: 90 mg/day for men, 75 mg/day for women 2, 1, 3, 4
- European Union (EFSA): 110 mg/day for men, 95 mg/day for women 2, 1
- Germany/Austria/Switzerland (DACH): 110 mg/day for men, 95 mg/day for women 2, 5
- Countries focused on scurvy prevention only (UK, Australia, India, FAO/WHO): 40-45 mg/day 2
The higher European recommendations (95-110 mg/day) are based on maintaining optimal plasma vitamin C concentrations around 50 µmol/L and replacing daily metabolic turnover, representing a more health-optimizing approach rather than merely preventing deficiency. 2, 1, 5
Populations Requiring Higher Intake
Smokers
- Male smokers: 155 mg/day 5
- Female smokers: 135 mg/day 5
- Rationale: Smokers have 40% higher metabolic turnover and lower plasma levels than non-smokers 5
Pregnant and Lactating Women
- Pregnant women: Additional 10-20 mg/day above baseline (total ~85-110 mg/day) 2
- Lactating women: Additional 20-60 mg/day above baseline (total ~95-150 mg/day) 2
- Pregnancy complications and fetal development require enhanced vitamin C status 2
Older Adults
- Standard recommendations apply, but special attention needed for those in long-term care or with poor dietary intake 2
- A small glass of unsweetened orange juice daily helps achieve adequate intake 2
- Vitamin C supplement may be needed when diet is poor, as advised by a physician 2
Patients with Chronic Disease
- Chronic oxidative stress conditions: 200-500 mg/day 1
- Post-bariatric surgery patients: 200-500 mg/day long-term maintenance 1
Upper Safety Limit
The Tolerable Upper Intake Level (UL) is set at 2,000 mg/day for adults, based on gastrointestinal upset that can occur with excessive doses. 1, 6, 4
Critical Contraindications
Patients with hemochromatosis or iron overload conditions must completely avoid vitamin C supplements, as vitamin C accelerates iron mobilization and can cause fatal cardiac complications. 1, 7
- If vitamin C is medically necessary for other reasons in iron overload patients, limit to 500 mg/day only after physician consultation 7
Minimum vs. Optimal Intake
The 40-45 mg/day threshold prevents scurvy but does not achieve tissue adequacy or optimal health 2, 1:
- Scurvy prevention: 40-45 mg/day 2
- Tissue saturation and antioxidant protection: 75-110 mg/day 2, 1
- Optimal health perspective: Some authorities suggest 200+ mg/day, though this remains debated 8
Common Pitfalls
- Don't rely on the outdated 60 mg/day recommendation from 1989, which was based solely on scurvy prevention 2
- Body weight is not factored into current recommendations, despite being a significant predictor of vitamin C status and requirement 2
- Oral absorption is limited at higher doses due to saturation of intestinal transporters; doses above 200 mg have progressively lower absorption 1
- Tea consumption with meals interferes with iron absorption and should be avoided if iron deficiency is a concern 2
Practical Dietary Sources
Foods high in vitamin C include citrus fruits (oranges, lemons, limes), tomatoes, potatoes, and green leafy vegetables 3. Five servings of fruits and vegetables per day typically provides 200 mg of vitamin C 8.