Ionized Calcium (Ca2+) and Hydrogen ions (H+) compete for binding to Albumin (-) and other negatively charged protein molecules.
WHEN pH is low (acidosis)
- Increase in Hydrogen (H+) molecules and therefore less protein binding of Ca2+, INCREASES serum Ca2+ levels.
WHEN pH is high (alkalosis)
- Decrease in Hydrogen (H+) molecules and therefore more protein binding of Ca2+, DECREASES serum Ca2+ levels.
- Nakamaru Y, Schwartz A. The Influence of Hydrogen Ion Concentration on Calcium Binding and Release by Skeletal Muscle Sarcoplasmic Reticulum. The Journal of General Physiology. 1972;59(1):22-32.
Cooper MS, Gittoes NJL. Diagnosis and management of hypocalcaemia. BMJ : British Medical Journal. 2008;336(7656):1298-1302. doi:10.1136/bmj.39582.589433.BE.
- Bushinsky DA, Monk RD. Electrolyte quintet: calcium. Lancet 1998;352:306-11