Beyond nutrition and cost, other factors come into play in choosing a calcium form with desirable attributes of taste, texture and color. Some calcium forms on the market are gritty and may also give foods off-tastes. Ground calcium carbonate may be as fine as 4µm, but more typically is between 8-12µm.
One product that has overcome this barrier is VICALity Albafil[r] precipitated calcium carbonate PPC by Specialty Minerals Inc. (Bethlehem, Pa.). VICALity Albafil PPC is a precipitated form of calcium carbonate that provides a smaller particle size, about 0.7µm. The process for manufacturing this ingredient involves calcination of natural calcium carbonate to lime and carbon dioxide. Lime is reacted with water to form calcium hydroxide, allowing heavy metals and other impurities to separate out. Calcium carbonate is reformed in a precipitation process by reaction with carbon dioxide.