Vitamins are chemical substances found in small quantities in natural foods which are essential elements of the diet and which are necessary for the proper growth and development of the body and for the prevention of certain disorders of health. A full and balanced dietary must contain a sufficiency of all the vitamins as well as correct proportions of protein, fat, carbohydrate and mineral salts. Absences or deficiency of vitamin from the diet lead to the " deficiency diseases," scurvy, rickets, beri-beri, pellagra and to other recognized states of ill-health. A full and natural diet, containing adequate amounts of animal fats, including milk, butter and cheese, cereals which have not been refined, fresh fruit and green vegetables, and animal flesh and internal organs (kidneys, liver and sweetbread) should provide a sufficiency of vitamins for health, but, under the conditions of present-day civilization with a tendency to the refinement (and consequent debasement) of natural foods, vitamin shortage is liable to arise.
Vitamins are divided into the fat soluble and the water soluble. The former include vitamin A, D, E, and K, and the latter vitamin B (complex), C and P.
This is found in animal fats (excluding lard), egg yolk and most green vegetables. In plants, it is developed as carotene, and this is converted into true vitamin A by the liver. The richest natural sources of vitamin A (as well as vitamin D) are the livers of the cod and the halibut. Vitamin A is essential for normal growth and for the protection of mucous membranes against bacterial or germ infection. Lack of vitamin A leads to an eye disease, xerophthalmia, and to defective formation of the dentine and teeth enamel. It is related to night blindness.
Vitamin B Complex
Vitamin B1 (Aneurin; Thiamine) is found in the husks of cereals such as rice and wheat. It is also found in yeast, fresh fruits and vegetables, egg yolk, liver and kidney. It can be prepared synthetically when it is called aneurin or thiamine. The milling of cereals deprives them of most of their vitamin Bi, and a deficiency of this vitamin leads to a disease, beri-beri, a form of neuritis.
Vitamin B2 has a complex structure. It is found in beef, liver, yeast and milk. One factor is nicotinic acid which prevents the disease called pellagra. Another is riboflavin and dietary deficiency of this vitamin is associated with scaliness and inflammation of the lips and cracks at the corners of the mouth. Other factors in the vitamin B2 complex are pyridoxine (B6) and pantothenic acid.
This vitamin is found in fresh fruits, especially the citrus fruits, in green vegetables, milk, cereals, peas and beans. Its chemistry has been established and the synthetic product is called ascorbic acid. Vitamin C is readily destroyed by heat and it is affected by alkalis such as bicarbonate of soda. A deficiency of vitamin C in the dietary leads to scurvy. This condition may arise in babies fed on artificial foods.
This vitamin is found in animal fats, notably the liver oils of the halibut and cod, in milk, and egg yolk. It can be prepared artificially by the action of ultra-violet rays upon a substance ergosterol and to this vitamin D preparation, the name of calciferol is given. By irradiation it is possible to increase the vitamin D content of milk. Vitamin D aids the absorption of phosphorus and calcium from the food into the blood and thus into the bones. Inadequate vitamin D in the dietary leads to rickets. Excessive intake of vitamin D may be harmful by causing a deposition of calcium and phosphorous salts in certain tissues.
This is found in the germ of whole cereals and the oil of green leaves. It is associated with the reproductive function.
Insufficiency of this vitamin in animals is a cause of sterility and it is probable that some cases of sterility in human beings is due to this cause.
This is found in hog's liver, fat and green leaves. It is necessary for the clotting of blood. Synthetic preparations have been made and used successfully in the treatment of bleeding states in infancy, and in cases of jaundice where there is a tendency to bleeding. It has also been used in the treatment of chilblains.
This vitamin is found in citrus fruits and is considered to be necessary for the maintenance of healthy blood capillaries. Its absence is thought to lead to fragility and rupture of the capillaries.