Table 1.

Threshold intake and mean calcium balance per age group

Age group	Threshold intake (mg/day)	Threshold balance (mg/day)
0–1 yrs	1090	+ 503 ± 91
2–8 yrs	1390	+ 246 ± 126
9–17 yrs	1480	+ 396 ± 164
18–30 yrs	957	+ 114 ± 133
> 30 yrs	583	+ 72 ± 35

Following analysis of calcium balance studies in 519 healthy individuals, this table shows the threshold intake at which the calcium balance does not increase further with increasing intake, and the mean balance for each age group. Under the age of 30 years, the calcium balance is always positive due to skeletal calcium accrual, but as more mineral is laid down, and peak bone mass is reached, the balance mean becomes smaller. Adapted from Matkovic & Heaney [26]. Over 30 yrs adapted from [32–34]