Originally Posted by
Diggie's Friend
The "NOW" brand has a greater volume by measure than Pure Bulk does. From research about the same about of calcium is absorbed into the bloodstream. And though C. carbonate is lower in volume, the advantage is lost from it having a high propensity to bond with oxalic acid.
Calcium citrate is greater in volume because it includes the 'anion' that is the organic compound that in the case of Calcium citrate is the citrate, which makes this form of calcium more absorbable more soluble, and as explained, less likely to bond with oxalic acid, so that more calcium is made available to the bones. It is a form naturally found in milk and mammal bones. Over the 8 years of using C. citrate was included in a gray squirrel diet, whether added to organic plain low fat yogurt, or a moist food, the squirrel slurped it all up.