The History Of Vitamins

THE HISTORY, USE AND EFFECTIVENESS OF

VITAMINS AND NUTRIENT SUPPLEMENTS

A Vitamin is any organic compound required by the body in small amounts for metabolism, to

protect health, and for proper growth in children. Vitamins also assist in the formation of

hormones, blood cells, the chemicals of the nervous-system, and genetic material. The

various vitamins are not chemically related, and most differ in their physiological

actions. They generally act as catalysts, combining with proteins to create metabolically

active enzymes that in turn produce hundreds of important chemical reactions throughout the

body. Without vitamins, many of these reactions would slow down or stop. The intricate ways

in which vitamins act on the body, however, are still far from clear. The 13

well-identified vitamins are classified according to their ability to be absorbed in fat or

water. The fat-soluble vitamins A, D, E, and K are generally consumed along with

fat-containing foods, and because they can be stored in the body's fat, they do not have to

be consumed every day. The water-soluble vitamins, the eight B vitamins and vitamin C,

cannot be stored and must be consumed frequently, preferably every day. The body can

manufacture only vitamin D, all others must be derived from the diet. Lack of them causes a

wide range of metabolic and other dysfunction's. In 21"the U.S., since 1940, the Food and

Nutrition Board of the National Research Council has published recommended dietary

allowances for vitamins, minerals, and other nutrients". Expressed in milligrams or

international units for adults and children of normal health, these recommendations are

useful guidelines not only for professionals in nutrition

(Pg 18) but also for the growing number of families and individuals who eat irregular meals and rely on prepared foods, many of which are now required to carry nutritional labeling.

A well-balanced diet contains all the necessary vitamins, and most individuals who follow

such a diet can correct any previous vitamin deficiencies. However, persons who are on

special diets, who are suffering from intestinal disorders that prevent normal absorption

of nutrients, or who are pregnant or lactating may need particular vitamin supplements to

bolster their metabolism. Beyond such real needs, vitamin supplements are also often

believed to offer ocureso for many diseases, from colds to cancer; but in fact the body

quickly eliminates most of these preparations without absorbing them. In addition, the

fat-soluble vitamins can block the effect of other vitamins and even cause severe poisoning

when taken in excess. Vitamin A is a pale yellow primary alcohol derived from carotene. It

affects the formation and maintenance of skin, mucous membranes, bones, and teeth, vision,

and reproduction. An early deficiency symptom is night blindness which is the difficulty in

adapting to darkness. Other symptoms are excessive skin dryness, lack of mucous membrane

secretion, causing susceptibility to bacterial invasion, and dryness of the eyes due to a

malfunctioning of the tear glands, a major cause of blindness in children in developing

countries. The body obtains vitamin A in two ways. One is by manufacturing it from

carotene, a vitamin precursor found in such vegetables as carrots, broccoli, squash,

spinach, kale, and sweet potatoes. The other is by absorbing ready-made vitamin A from

plant-eating organisms. In animal form, vitamin A

(Pg 19)

is found in milk, butter, cheese, egg yolk, liver, and fish-liver oil. Although one-third of American children are believed to consume less than the recommended allowance of vitamin A, sufficient amounts can be obtained in a normally balanced diet rather than through supplements. Excess vitamin A can interfere with growth, stop menstruation, damage red blood corpuscles, and cause skin rashes, headaches, nausea, and jaundice. Known also as vitamin B complex, these are fragile, water-soluble substances, several of which are particularly important to carbohydrate metabolism.

Thiamine, or vitamin B1, a colorless, crystalline substance, acts as a catalyst in

carbohydrate metabolism, enabling pyruvic acid to be absorbed and carbohydrates to release

their energy. Thiamine also plays a role in the synthesis of nerve-regulating substances.

Deficiency in thiamine causes beriberi, which is characterized by muscular weakness,

swelling of the heart, and leg cramps and may, in severe cases, lead to heart failure and

death. Many foods contain thiamine, but few supply it in concentrated amounts. Foods

richest in thiamine are pork, organ meats such as liver, heart, and kidney, brewer's yeast,

lean meats, eggs, leafy green vegetables,