Foods, their selection and preparation

Table II • Per 100 grams Per pound Approximate Vitamin-A Values Fish-liver oils2 . Deep-green leaves such as those of broccoli, chard, dandelion, escarole, kale, mustard, spinach, 200,000-300,000 About 1,000,000 of the Edihle turnip tops . 10.000- 20,000 45,000-90,000 Broccoli, entire edible part . 3,000- 9,000 13,000-40,000 Portion Carrots, sweet potatoes, apricots (dried) .... 2,000- 10,000 9,000-45,000 of Some Butter . 2,000- 4,000 9,000-18,000 Eggs, cheese3 . 1,000- 2,000 4,500- 9,000 Typical Foods 1 Tomatoes, cantaloupe . 900- 1,300 4,000- 6,000 Milk . Potatoes4 . 30- 40 140- 180 potatoes. Thin green leaves are an especially rich source. Vitamin A is only slightly soluble in water, and is more stable under heat than some of the other vitamins. Table II lists the more important food sources of vitamin A, and the A values of definite amounts of the edible portions of these. The vitamin B family has increased in size during the last few years. They are a clannish group and commonly occur together in a wide variety of natural foods. Some foods are especially important as a source of one or another member of this important group of nutrients. For the group as a whole, the glandular organs, the seeds, and the growing portions of plants are the important sources. These vitamins are all measured in micrograms or milligrams. It is a co-operative family the work of one member frequently supplements that of another. Three members of this group, thi- 1H. C. Sherman, Principles of Nutrition and Nutritive Value of Foods, Miscellaneous Publication No. 546, United States Department of Agriculture, p. 20. 2Figures here given represent a presumably safe average for fish oils generally, including the long-used cod-liver oil. There are, of course, particular species of fish, such as halibut and percomorph, the liver oils of which have much higher vitamin-A values. ’Including common American cheese (Cheddar type) and other kinds made from whole milk. ^Breeding experiments for the production of potatoes of distinctly higher vitamin-A value have been reported. amine, riboflavin, and niacin, have been studied in sufficient detail to establish defi¬ nitely the amounts desirable each day. These will be discussed in detail below. There are at least seven other members5 of this group, and information is fast developing as to their functions and the amounts in different foods. For the present it is safe to assume that a food supply which contains satisfactory amounts of thiamine and riboflavin from natural sources will not be lacking in the other factors of the B complex. For this reason, retention of vitamins in processing foods seems a wiser procedure than enrich¬ ment with only those B factors now readily available in synthetic form. Thiamine, or vitamin B1? is necessary for good appetite and is essential to the use of the energy in our food. When this vitamin is present in inadequate amounts, the carbo¬ hydrates in the body fluids are incompletely oxidized and form by-products that decrease the appetite and cause general listlessness, sluggish digestive systems, and nervous ir¬ ritability. The absence of this vitamin in the diet brings on muscular paralysis and the deficiency disease known as beri-beri. Thiamine is especially important in the diets of nursing mothers and infants. With¬ out enough of it, the mother’s milk may be