In meat eating of the type so common in America, in which ham, steaks, roasts, chops, and other cuts which are derived from muscle, are almost exclusively used, the only important supplementing effect of meat on the remainder of the diet lies in the enhancement of the protein and in the increase in the phosphorus content. When glandular organs are eaten, these add considerable amounts of fat-soluble A and water-soluble B, but when cooked, no water-soluble C. In general we eat so little of the glandular organs that this source of the uncharacterized factors is nearly negligible.

The liver and kidney are, however, so exceptionally valuable in enhancing the biological values of certain cereal grains, that they may well find a regular place in the diet under certain conditions where it is desired to have a low protein intake of exceptionally high quality (41).