Scientific Opinion on Dietary Reference Values for vitamin A
Following a request from the European Commission, the Panel on Dietetic Products, Nutrition and Allergies derived Dietary Reference Values for vitamin A. The Panel considered that a concentration of 20 µg retinol/g liver can be used as a target for establishing the Average Requirement (AR) for vitamin A. In the absence of a better characterisation of the relationship between vitamin A intake and liver stores, a factorial approach was applied. This approach considered a total body/liver retinol store ratio of 1.25, a liver/body weight ratio of 2.4 %, a fractional catabolic rate of body retinol of 0.7 % per day, an efficiency of storage in the whole body for ingested retinol of 50 % and reference weights for women and men in the EU of 58.5 and 68.1 kg, respectively. ARs of 570 µg retinol equivalent (RE)/day for men and 490 µg RE/day for women were derived. Assuming a coefficient of variation (CV) of 15 %, Population Reference Intakes (PRIs) of 750 µg RE/day for men and 650 µg RE/day for women were set. For infants aged 7–11 months and children, the same equation as for adults was applied by using specific values for reference weight and liver/body weight ratio. For catabolic rate, the adult value corrected on the basis of a growth factor was used. ARs range from 190 µg RE/day in infants aged 7–11 months to 580 µg RE/day in boys aged 15–17 years. PRIs for infants and children were estimated using a CV of 15 % and range from 250 to 750 µg RE/day. For pregnancy and lactation, additional vitamin A requirements related to the accumulation of retinol in fetal and maternal tissues and transfer of retinol into breast milk were considered and PRIs of 700 and 1 300 µg RE/day, respectively, were set.