Ca2+ intake: 200-1000 mg/day, 5-25 mmol/day 40 - 50 % of the plasma Ca2+ content (2,2 - 2,6 mmol/L) is protein-bound.
- This bound protein is not filtrating in the glomeruli,
- The non-protein bound Ca2+ is freely filtrating
- 97-99% of the filtrated Ca2+ is reabsorbed in the tubular system.
The daily excretion is 2,5 - 7,5 mmol Ca2+.