Scientific Opinion on Dietary Reference Values for calcium
Following a request from the European Commission, the Panel on Dietetic Products, Nutrition and Allergies derived Dietary Reference Values for calcium. These include Average Requirement (AR), Population Reference Intake (PRI) and Adequate Intake (AI). For adults, data were analysed from a number of balance studies undertaken in North America and the mean value at which calcium intake equals excretion was calculated as 715 mg/day in adults ≥ 25 years. An allowance for dermal calcium losses (not included in the balance data) of 40 mg/day was added to derive an AR of 750 mg/day. The upper bound of the 95 % prediction interval at the estimated population mean at null balance (which represents the 97.5th percentile of the distribution of the individual predictions for each calcium intake level) was 904 mg/day, and when dermal losses are added this gives a PRI of 950 mg/day for adults ≥ 25 years. For infants (7–11 months), an AI was derived by extrapolating the average amount of calcium absorbed by exclusively breast-fed infants (120 mg/day) using isometric scaling and assuming an absorption of 60 %, and was calculated as 280 mg/day. The AR for children was derived using the factorial approach. The total quantity of calcium required for bone accretion and replacement of endogenous losses was adjusted for percentage absorption to derive PRIs for children aged 1–3, 4–10 and 11–17 years of 450, 800 and 1 150 mg/day, respectively. The PRI for young adults (18–24 years), who still accumulate calcium in bones, is 1 000 mg/day. This is the intermediate value between children aged 11–17 years and adults. Taking into consideration adaptive changes in calcium metabolism that occur during pregnancy and lactation, the PRI for non-pregnant women also applies to pregnant and lactating women of the same age group.