The Acid-Base Balance
Extensive research has shown that foodstuffs differ in relation to their acid and basic contents. In certain foods, bases or alkalis predominate, while in others the mineral acids predominate.
 A proper acid and base balance is essential for health and is maintained where a normal condition exists in the body fluids. The alkalinity of the blood depends entirely upon residues left by the foodstuffs in the body. Certain foods leave alkaline, or basic residues and help to maintain the alkalinity of the blood, while others leave acid residues which tend to lower the blood alkalinity.
All flesh foods leave highly acid residues and lessen the alkali reserve of the blood to a marked degree. Meat extracts, broths, bouillon, and gravies all belong in the group of acidifying foods.
 Eggs are also acid but less so than meats.
 Cereals of all sorts, including breads of every description, contain a preponderance of acids, though much less than meats.
Milk is slightly alkaline.
Nearly all fruits, also green vegetables and root vegetables of all sorts, are strongly basic and tend to alkalinize the body fluids. They produce alkaline ash.
A few fruits, such as cranberries, plums, and prunes must be placed in the acid-producing group because of the presence of benzoic acid, which is not oxidized in the body.
 The foods producing an acid ash are: cheese, eggs, fish, meat, bread, cereals, pastry, rice, dried corn macaroni, spaghetti, white flour, chocolate, lentils, and nuts (except almonds).
 Neutral foods are: butter, cream, honey, unrefined sugar, and natural syrups.
  In general it is better to select foods which provide a large basic (alkaline) margin so as to add to the alkali reserve of the body.
Commercial anti-acids or alkalizers and baking soda tend to a condition of alkalosis. These inorganic minerals, for the most part, do not become an actual part of the alkali reserve of the body.
Mineral Salts
Too often the organic Food Salts or Mineral Elements are treated as unimportant substances, when in reality they play a most important part in our nutrition.
That the blood may be supplied with these necessary elements in balanced proportion, a correct understanding of the foods supplying these essentials, as well as a knowledge of the nature of them is necessary.
Calcium and Phosphorus are very apt to be deficient in the average American dietary. Calcium stands for strength and durability. If there is a deficiency of this mineral, the gelatin of the bones loses its chemical support and begins to decompose. It is utilized in bone and teeth formation, coagulation of blood, and aids in regulating mineral metabolic. Phosphorus is an important constituent of all cells; it is necessary for the utilization of organic foodstuffs, and is also required in bone and teeth formation.
 Iodine is found in small quantities in many leafy vegetables and fruits, particularly in sea lettuce, radishes, strawberries, pineapple, green kidney beans, asparagus, cabbage, and garlic, if grown in non-goiterous regions. It is essential for the formation of the organic iodine compound-Thyrosin-which regulates some of the metabolic functions of the organism. A lack of this element causes goiter.
 Iron occurs in the organism as a complex organic compound. In the soil the iron is carried to the leaves where it takes part in the formation of the chlorophyll granules, or green coloring matter. The body can use this mineral only in organic form; it serves the distinct purpose of producing the hemoglobin of the red blood corpuscles. It is the hemoglobin that carries oxygen through the blood to all parts of the body. Iron is perhaps the most active element in the organism and needs, therefore, to be renewed oftener than some of the other elements. All green leafy vegetables always contain the largest amount of iron compounds; fruits and nuts contain an appreciable amount, strawberries and walnuts ranking highest. In eggs, iron is mostly contained in the yolk.
 Manganese, like iron, is an oxygen carrier. It is antagonistic to calcium. Very necessary for mineral balance in the body. Traces of this element are found in most vegetables.
Sodium, Potassium, and Magnesium are supplied quite generously in most vegetables, fruits, and cereals. These salts in solution in the blood and lymph are responsible for maintaining the osmotic pressure between cells and surrounding fluid. Sodium also serves to make the lime and magnesium salts more soluble for perfect assimilation, otherwise lime and magnesium would soon be deposited in the body. Potassium serves as the mineral basis of muscular tissues, giving them their characteristic pliancy, and magnesium has a peculiar vitalizing power.
 Sulphur is most often found in combination with protein, and to some extent in asparagus, cauliflower, onions and radishes. It is a necessary constituent of every cell and especially characteristic of the hair and nails. Like silicon, it gives to the body softness, elasticity, and pliability.
Vitamins
  Science has definitely proven that nutrition and growth are profoundly affected by the vitamins in food. Not only do specific diseases develop if the vitamins are absent, but malnutrition of all grades occurs when they are not in sufficient amounts.
The vitamin family now consists of eight and probably nine vitamins. Those with which we are most familiar are known as A, B, C, and E. At first it was believed that vitamin B was a single factor, but research has broken it up into six parts. It is known in England as B1 B2 B3 B4 B5 B6. In America B2 is called vitamin G.
In studying the vitamins it seems better to consider them individually because their physiological and chemical properties are quite distinct.
Vitamin A is the growth and anti-ophthalmic vitamin. Deficiency of this results in malnutrition, stunted growth, and low resistance to infections. Foods rich in this vitamin are butter, cream, egg yolk, spinach, carrots, pineapples, prunes, alfalfa, and avocados.
Vitamin B is the anti-neuritic factor that protects against polyneuritis. Deficiency results in loss of appetite, constipation, nervousness, muscle fatigue, anemia, and abnormal heart action. Foods rich in vitamin B are whole grains, nuts, yeast products, cereal germs, spinach, tomatoes, asparagus, egg yolk, milk, alfalfa, and beet leaves.
 Vitamin C. The omission of this vitamin from the diet produces scurvy, sore mouth, stiff joints, tooth defects, malnutrition and retarded growth. Foods rich in C are oranges, lemons, tomatoes, pineapples, raspberries, apples, bananas, cabbage, lettuce, onions, potatoes, turnips.
  Vitamin D is the so-called antirachitic factor, and controls the metabolism of calcium and phosphorus in bone-building and teeth formation. It prevents rickets, poor teeth, and possibly lung diseases. This vitamin may be called the Sunshine Vitamin because foods can be increased in vitamin D by exposing them to ultraviolet light, a process called irradiation. This proved that it is not exclusively a function of the rays of the sun acting on live tissues. Foods rich in D are vegetables, whole milk, egg yolk, and cod-liver oil.
Vitamin E. This vitamin appears most abundant in the oil of the wheat germ, but is also found in seeds and green leaves, and in several vegetable oils. It is necessary for reproduction and lactation.