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
