Following a request from the European Commission, the Panel on Dietetic Products, Nutrition and Allergies was asked to re-evaluate the safety in use of calcium and to provide, if necessary, revised Tolerable Upper Intake Levels (ULs) of calcium for all relevant population groups.
Calcium is important for the maintenance of healthy teeth and bones, cell signalling, coagulation, muscle contraction, neural transmission and many other functions. Calcium is the fifth most abundant element in the human body. Some 99 % of the total calcium of the body is located in bones and teeth, mostly as calcium hydroxyapatite. Bone mineral provides structure and strength to the body, and a reservoir of calcium that helps to maintain a constant concentration of calcium in the blood.
Foods vary widely in calcium content. The best sources are milk and milk products, which provide about 45 to 70 % of the dietary calcium in European diets. Some plants, drinking and mineral water, and food supplements are also good sources of well absorbable calcium.
A number of potential adverse effects of excessive calcium intakes have been proposed. These include hypercalciuria, deterioration of kidney function, kidney stone formation, the milk-alkali syndrome (MAS), vascular calcification, increased risk of cardiovascular disease and increased risk of prostate cancer.
The SCF (2003) based the derivation of a UL for calcium on the evidence of different intervention studies of long duration, some of which were placebo controlled, in which total daily calcium intakes of 2,500 mg from both diet and supplements were tolerated without adverse effects. Because of the abundance of data, the application of an uncertainty factor was considered unnecessary. A UL of 2,500 mg of calcium per day from all sources was proposed for adults, and for pregnant and lactating women.
A number of placebo controlled human intervention studies in adults published since then also show that total daily calcium intakes of 2,500 mg from both diet and supplements are tolerated without adverse effects.
The Panel notes that new case reports have become available on consumption of calcium supplements and the CAS/MAS syndrome. However, the Panel considers that no dose-response relationships can be derived from these.
The Panel considers that no relationship has been established between long-term calcium intakes from diet and supplements and increased risk of nephrolithiasis, cardiovascular disease or prostate cancer.
The Panel concludes that no new data have become available which would require a revision of the UL for calcium for adults, including pregnant and lactating women, of 2,500 mg, and that no new data have become available which would allow the setting of a UL for infants, children or adolescents.
Data from European populations indicate that intakes of calcium in high consumers among adult males can be close to the UL. Although available data do not allow the setting of a UL for infants, children or adolescents, no risk has been identified with highest current levels of calcium intake in these age groups.