The ordinary student of nutrition has paid a good deal of attention to individual vitamins, but has paid little attention to minerals. The ordinary diet, composed largely of white flour and sugar, does not contain this much calcium. The conclusion reached by Dr. Bernheim is that calcium deficiency is universal in all civilized countries. Another important point brought out by Dr. Bernheim is that different forms of calcium have different degrees of absorbability.
Some calcium salts are readily absorbable and are used in the body.
It is well understood at the present time that the best forms of calcium are those which have gone through some kind of animal metabolism. Ground bone is more easily absorbed than other forms, and is properly used a good deal in baby foods. The forms of calcium that exist in milk and ,cheese have been through the metabolism of the cow, and therefore have been metabolized and are easily absorbed by the human animal. Milk and milk products, then, furnish the best source of calcium. With a sufficient source of calcium, nerves are less irritable.