Calcium has manifold functions in the human body, not only as a structural factor in the bones and teeth, but also as a prerequisite to normal neuromuscular action and the clotting of blood. Its unique osmotic importance in the blood has been suggested; it exerts a significant influence on the movement and distribution of other mineral elements in the body. This recognized physiologic prominence of calcium has attracted the attention of investigators for many years. It is not surprising that the distribution and availability, the utilization by the organism and the human requirement are still themes of active interest in metabolism and nutrition.
Although milk with its 0.12 per cent of calcium is considered the best source of calcium, vegetables also contribute this element to the diet. When experimental animals are forced to obtain a considerable proportion of their daily calcium from vegetable sources, the availability of this element is