Recommended dietary allowance for vitamin C
Pro Research Analysisby 
Searched over 200M research papers
Recommended Dietary Allowance for Vitamin C: Prevention of Deficiency
The traditional recommended dietary allowance (RDA) for vitamin C has been set to prevent scurvy, a deficiency disease. Historically, values such as 45 mg/day and 60 mg/day for adults have been used, which are sufficient to prevent scurvy in most peoplePauling1974Carr1999Olson1987. A minimum intake of about 10 mg/day is needed to avoid deficiency symptoms.
Updated RDA Values and International Guidelines
Recent updates have increased the RDA in several countries. The Institute of Medicine (US) recommends 90 mg/day for men and 75 mg/day for women, while the European Food Safety Authority (EFSA) suggests 110 mg/day for men and 95 mg/day for womenProducts2013Eggersdorfer2020. These values are based on maintaining adequate body stores and plasma concentrations of vitamin C, not just preventing deficiencyProducts2013Levine1996Eggersdorfer2020.
Optimal Vitamin C Intake for Health Benefits
Research indicates that higher intakes of vitamin C may provide additional health benefits beyond deficiency prevention. Studies suggest that 90–100 mg/day is needed for optimal reduction of chronic disease risk, such as cancer, cardiovascular disease, and cataractsCarr1999Levine1999. Some experts propose increasing the RDA to 120 mg/day or even 200 mg/day to maximize health benefits, including immune function and antioxidant protectionCarr1999Levine1999Levine1996+3 MORE.
Pharmacokinetics and Functional Markers
Pharmacokinetic studies show that plasma and leukocyte saturation occurs at daily intakes of 100–200 mg, with no additional benefit at higher dosesLevine1996Eggersdorfer2020Frei2012. Bioavailability is complete at 200 mg/day, and doses above 400 mg/day do not provide further advantagesLevine1996Eggersdorfer2020Frei2012. Functional markers, such as neutrophil motility, support the recommendation for 200 mg/day as optimal for immune functionEggersdorfer2020Frei2012.
Safety and Upper Intake Levels
The tolerable upper intake level for vitamin C is generally considered to be 1,000 mg/day, as higher intakes may lead to adverse effects in some individualsLevine1999Levine1996Ausman1999. Most recommendations advise not exceeding this amount.
Conclusion
While the minimum vitamin C intake to prevent deficiency is around 10–45 mg/day, current evidence supports higher daily intakes—90–120 mg/day for general health, and up to 200 mg/day for optimal immune function and chronic disease prevention. Intakes above 400 mg/day do not show additional benefits, and daily consumption should remain below 1,000 mg to avoid potential adverse effectsCarr1999Levine1999Products2013+4 MORE.
Sources and full results
Most relevant research papers on this topic