Vitamines in green leaves

In view of the very scanty data recorded respecting the relative content of vitamine in green foods compared with other plant and animal products which have been studied more in detail, we have fed albino rats on diets containing, as the source of water-soluble vitamine, spinach, cabbage, clover, timothy and alfalfa, dried in their immature state. Far less dried spinach supplies sufficient water-soluble vitamine to promote normal growth than do whole wheat, soy beans, dried egg, meat, milk or potatoes. Spinach leaves are much richer in the fat-soluble vitamine than are most of the products used in our ordinary rations. Thus rats fed for over 160 days, during which they consumed only 25 to 34 grams of spinach, have grown from 60 to 250 grams at a nearly normal rate and have as yet shown no evidence of deficient nutrition. Such quantities are not much larger than have heretofore been considered to be necessary when butter fat supplied the fat-soluble vitamine. A somewhat larger quantity of cabbage than of spinach leaves is needed to promote normal growth. It probably also contains the fat-soluble vitamine. Timothy, clover and alfalfa contain both vitamines, but further experiments are needed to establish the relative amounts of these. Tests of a large variety of tubers, stems, leaves and fruits are now in progress.

If one may draw conclusions from the limited data at present available, it seems that the green vegetables and fodders are richer in vitamines than most of the staples like meats, potatoes, cereals, fats and sugar products, in the diet of man. Therefore they unquestionably contribute largely to the dietary need of the average person.