It is evident that blood calcium may be found under different conditions and in various combinations. This fact has been expressed in several ways, one of the most common being by the use of the classfication "diffusible calcium" and "nondiffusible calcium." It must, nevertheless, be kept in mind that this simple classification is far from giving an exact idea of the complexity of the question. Hess1 has said that calcium may be found in the blood in at least four states: two diffusible and two nondiffusible. Of the diffusible portion, two thirds is an absorbable calcium-phosphorus compound, the rest being ionized calcium. About one fourth of the nondiffusible fraction is absorbable by dry barium sulfate (40 per cent solution), and the remaining three fourths is accepted by Hess as being in combination with the serum protein.
For the time being we have adopted the designations of diffusible calcium and
GARRAHAN JP, THOMAS GF. CALCIUM FRACTIONS IN INFANTILE SPASMOPHILIA. Am J Dis Child. 1940;60(2):249–255. doi:10.1001/archpedi.1940.02000020003001
Customize your JAMA Network experience by selecting one or more topics from the list below.
Create a personal account or sign in to: