Several commercial calcium salts have been used for calcium fortification of products. From an economical point of view, the higher the calcium content of the salt, the less will be need to be added. However, a responsible manufacturer would also consider the high nutritional value, cost effectiveness and minimal effect on consistency, mouthfeel and taste on the products. Bioavailability (absorption) and solubility are the main measures when comparing the nutritional value of calcium salts (Jungbunzlauer, 2003; Susan et al, 2008).
In general, organic salts of calcium such as Lactate Gluconate are more bioavailable than inorganic salts such as carbonate. Calcium carbonate is practically insoluble without acid secretion. Therefore the low solubility reduces the availability of calcium from calcium carbonate (Susan et al., 2008).
Calcium carbonate is generally the least expensive calcium salt and contains higher calcium content but it is practically insoluble in water. Calcium Lactate Gluconate is pH independent and dissolves quickly in water (Jungbunzlauer, 2003).
Calcium Lactate Gluconate has neutral taste which facilitates the formulation of products whereas calcium carbonate has chalky taste which may affect the flavour of products when used in large quantity. Some studies show that Calcium Lactate Gluconate that is added to dairy products and high protein products caused coagulation after sterilisation in the product but can be prevented by adding a chelating agent (Jungbunzlauer, 2003; Susan et al, 2008).
Most studies show that the bioavailability of Calcium Gluconate Lactate is higher than calcium carbonate. However, bioavailability of calcium depends on absorbability and the incorporation of absorbed calcium into bone and also the urinary excretion and fecal loss of calcium. Certain types of food such as food enriched in vitamin D increase the likelihood absorption of calcium into the bone. Others factors such as age, physiological factors and hormones regulation play a major role in the bioavailability of absorbed calcium (Jungbunzlauer, 2003; Susan et al, 2008).
Jungbunzlauer. (2003). International Food Ingredients: How can we get more calcium? (pp. 24-26). UK: United Business Media.
Susan, R., Connie, M. W., & Jeffrey, J. K. (2008). Advances in Food and Nutrition Research(pp. 219-324). Amsterdam: Elsevier.