Scientific Opinion on Dietary Reference Values for vitamin A

Abstract

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. Vitamin A is involved in vision as retinal, which plays a central role in the mechanisms of phototransduction, and in the systemic maintenance of the growth and integrity of cells in body tissues through the action of retinoic acid, which acts as regulator of genomic expression. The most specific clinical consequence of vitamin A deficiency is xerophthalmia, which encompasses a clinical spectrum of ocular manifestations. In low-income countries, vitamin A deficiency in young infants and children has been associated with increased infectious morbidity and mortality, including respiratory infection and diarrhoea. © EuropeanPreformed vitamin A is efficiently absorbed (70-90 %). The absorption of β-carotene appears to be highly variable (5-65 %), depending on food-and diet-related factors, genetic characteristics and the health status of the subject. The intestine is the primary tissue where dietary provitamin A carotenoids are converted to retinol. Retinol, in the form of retinyl esters, and provitamin A carotenoids enter the body as a component of nascent chylomicrons secreted into the lymphatic system. Most dietary retinol (in chylomicrons and chylomicron remnants) is taken up by the liver, which is the major site of retinol metabolism and storage. Hepatic retinyl esters are hydrolysed to free retinol, and delivered to ti...

Assessment of genetically modified maize Bt11 × MIR162 × MIR604 × 1507 × 5307 × GA21 and subcombinations, for food and feed uses, under Regulation (EC) No 1829/2003 (application EFSA‐GMO‐DE‐2011‐103)

“…Milk, meat, vegetables and derived products are the main sources of vitamin A in the diet. Cereals and cereal-based products contribute much less to the total intake of vitamin A, with contributions in the adult population ranging between 2.7% and 6.5% of the total (average contribution = 4.1%), with the maximum contribution (10%) estimated in adolescents (EFSA NDA Panel, 2015). The decrease observed in b-carotene is not considered relevant from a nutritional point of view.…”

“…Cereals and cereal-based products contribute much less to the total intake of vitamin A, with contributions in the adult population ranging between 2.7% and 6.5% of the total (average contribution = 4.1%), with the maximum contribution (10%) estimated in adolescents (EFSA NDA Panel, 2015). Milk, meat, vegetables and derived products are the main sources of vitamin A in the diet.…”

Supplementation during pregnancy: beliefs and science

“…Vitamin A supplementation European Food Safety Authority recommended dietary allowances for vitamin A intake in pregnancy and lactation are 700 mg retinol equivalent (RE)/d and 1300 mg RE/d, respectively [40]. The WHO does not recommend vitamin A supplementation during pregnancy as part of routine antenatal care for the prevention of maternal and infant morbidity and mortality [41].…”

Vitamin A in Health and Disease

“…Vitamin A is mainly found in human tissues in the form of retinyl esters, which explains why the vitamin is commercially produced and administered as esters of retinyl acetate or palmitate. Retinyl esters will subsequently be converted into retinols in the small intestine [1,2]. The pro-vitamin A comes from plant-derived foods primarily in oils, fruits and vegetables.…”

“…Both of these structural moieties are essential for the vitamin to exert biological activity. The β-ionone ring containing carotenoids include α-carotene, β-carotene and the xanthophyll β-cryptoxanthin [2].…”