EFSA Publishes Reference Values for Vitamin C and Manganese

5 Nov 2013 --- EFSA has set population reference intakes for vitamin C and adequate intakes for manganese as part of its ongoing work on Dietary Reference Values (DRVs). At the request of the European Commission, EFSA is updating advice issued previously on DRVs, taking into account new scientific evidence and recent recommendations issued at national and international level.

The two opinions were finalised by the NDA Panel after public consultations, ensuring that EFSA benefits from the widest range of information, data and views from the scientific community, stakeholders and other interested parties.

DRVs comprise a set of reference values such as average requirements, population reference intakes, adequate intakes, lower threshold intakes and tolerable upper intake levels. Scientific advice on DRVs is an important basis for the policy decisions of the European Union in the field of nutrition.

The Panel concluded that an Average Requirement (AR) can be derived from indicators of vitamin C status, as well as a Population Reference Intake (PRI) assuming a coefficient of variation (CV) of 10 %. Several health outcomes possibly associated with vitamin C intake were also considered but data were found to be insufficient to establish DRVs. For healthy adults, the AR is determined from the quantity of vitamin C that balances metabolic vitamin C losses and allows the maintenance of an adequate body pool characterised by fasting plasma ascorbate concentrations at around 50 µmol/L. In men, an AR of 90 mg/day of vitamin C and a PRI of 110 mg/day are proposed. As no value for metabolic losses is available in women, the AR for women is extrapolated from the AR for men on the basis of differences in reference body weight, and an AR of 80 mg/day and a PRI of 95 mg/day are proposed. For infants aged 7-11 months, the Panel has decided to retain the PRI of 20 mg/day set by the SCF (1993), as no suitable evidence has emerged since the previous assessment. For children and adolescents, the ARs for vitamin C are extrapolated from the ARs for adults taking into account differences in reference body weight, and PRIs are derived, ranging from 20 mg/day for 1 to 3 year-old children, to 100 and 90 mg/day for boys and girls aged 15-17 years, respectively. For pregnant and lactating women, vitamin C intakes of 10 mg/day and of 60 mg/day in addition to the PRI of non-pregnant non-lactating women are proposed.

Manganese is an essential dietary mineral which is a component of a number of metalloenzymes involved in amino acid, lipid and carbohydrate metabolism. A specific manganese deficiency syndrome has not been described in humans. The body is able to adapt to a wide range of manganese intakes by regulating both efficiency of absorption in the intestine and the quantity excreted via bile. There are no reliable and validated biomarkers of manganese intake or status and data on manganese intakes versus health outcomes are not available for DRVs for manganese. As there is insufficient evidence available to derive an average requirement or a population reference intake, an Adequate Intake (AI) is proposed. Mean intakes of manganese in adults in the EU are around 3 mg/day. In addition, null or positive balances have consistently been observed with intakes of manganese above 2.5 mg/day. An AI of 3 mg/day is proposed for adults, including pregnant and lactating women. For infants aged from 7 to 11 months, an AI of 0.02–0.5 mg/day is proposed, which reflects the wide range of manganese intakes that appear to be adequate for this age group. The AI for children and adolescents is based on extrapolation from the adult AI using isometric scaling and reference body weights of the respective age groups.