Vitamin C // Ascorbic Acid

Vitamin C Intake Recommendations

While in 1993 the2013 the European Food Safety Authority (EFSA) set population reference intakes (PRI) for vitamin C (62)European nutrition societies, like the ones in Germany, Austria and Switzerland(D-A-CH) (63), referred to these values to define reference values for vitamin C intake (recommended intake). 

 Age    Males: mg/day   Females: mg/day
Infants      
 7-11 months   20  
Children and adolescents      
 1–3 years   20  
 4–6 years   30  
 7–10 years   45  
 11-14 years   70  
 15–17 years 100   90
Adultsa      
 18 years and older 110   95
 Pregnant women
-   105
Lactating women -   155
a Smokers, D-A-CH
155   135

 

In 2013, EFSA stated that the average requirement (AR, applying to at least half of the population) to keep bodily vitamin C at healthy levels is an intake of 90 mg/day for men and 80 mg/day for women (63). The population reference intake (an ideal level for the majority of people) was set at 110 mg/day for men and 95 mg/day for women. These levels were sufficient, the expert panel said, to balance metabolic vitamin C losses and maintain fasting plasma ascorbate concentrations at about 50 micromoles/L (62).

In 2000, the U.S. Food and Nutrition Board revised the recommended dietary allowance (RDA) values for vitamin C upward, based primarily on the prevention of deficiency disease, rather than the prevention ofchronic disease and the promotion of optimum health. They used the near-maximal neutrophil concentration with minimal urinary excretion of ascorbate to provide antioxidant protection, which led them to define a Recommended Daily Allowances (RDA) (17).

RDA (mg/day) set by IoM:

 Life Stage   Age  Males: mg/day Females: mg/day 
Infants      
  0–6 months 40 (AIa) 40 (AI)
   7–12 months 50 (AI) 50 (AI)
Children      
   1–3 years 15 15
   4–8 years 25 25
  9–13 years 45 45
Adolescents      
  14–18 years 75 65
Adults      
  19 years and older 90 75
Smokers      
  19 years and older 125 110
Pregnancy      
  18 years and younger - 80
  19 years and older - 85
Breast-feeding      
  18 years and younger - 115
  19 years and older - 120
a AI: Adequate intake      

 

The recommended intake for smokers is 35 mg/day higher than for non-smokers, because smokers are under increased oxidative stress from the toxins in cigarette smoke and generally have lower blood levels of vitamin C (17).

Up to now, no functional biomarker was identified that could be used as a basis to define the dietary intake recommendations for vitamin C. New evidence support neutrophil motility as such a functional marker. Combined with established knowledge from pharmacokinetic studies and studies on cardiovascular diseases and common cold, intake recommendations should be increased to ≥200 mg/day which would be beneficial for the functioning of the immune system (73).

For a detailed overview of recommended daily intakes (PRIs/RDAs) of vitamins and minerals for adults derived from different countries and organizations see PDF.

Authored by Dr Peter Engel in 2010, reviewed and revised by Dr. Volker Elste on 22.05.2017