Upper Limits

FAO/WHO verbatim

Upper limits

Curhan, G.C., Willett, W.C., Speizer, F.E., Spiegelman, D. & Stampfer, M.J. 1997. Comparison of dietary calcium with supplemental calcium and other nutrients as factors affecting the risk for kidney stones in women. Ann. Internal Med., 126: 497-504.

Curhan, G.C., Willett, W.C., Rimm, E.B. & Stampfer, M.J. 1993. A prospective study of dietary calcium and other nutrients and the risk of symptomatic kidney stones. N. Engl. J. Med., 328: 833-838.

Burnett, C.H., Commons, R.R., Albright, F. & Howard, J.E. 1949. Hypercalcaemia without hypercalciuria or hypophosphatemia, calcinosis and renal insufficiency. A syndrome following prolonged intake of milk and alkali. N. Engl. J. Med., 240: 787-794.

Because of the inverse relationship between fractional calcium absorption and calcium intake(Figure 15), a calcium supplement of 1000 mg (2.5 mmol) added to a Western-style diet only increases urinary calcium by about 60 mg (1.5 mmol). Urinary calcium also rises very slowly with intake (slope of 5–10 percent) and the risk of kidney stones from dietary hypercalciuria must therefore be negligible.

In fact, it has been suggested that dietary calcium may protectagainst renal calculi because it binds dietary oxalate and reduces oxalate excretion.Toxic effects of a high calcium intake have only been described when the calcium is given as the carbonate in very high doses; this toxicity is caused as much by the alkali as by the calcium and is due to precipitation of calcium salts in renal tissue (milk-alkali syndrome).However, in practice we recommend an upper limit on calcium intake of 3 g (75 mmol).