Vitamins are the organic chemical compounds necessary to enable the body to utilize carbohydrates, fats, and proteins. Like enzymes, they help produce the right chemical reactions at the right time. The body can’t synthesize vitamins. When a particular vitamin is lacking in your diet, the chemical reaction that’s concerned with, can’t take place even if you have been eating balanced diet.
All the vitamins should be included in your diet. The B vitamins and vitamin C are water-soluble and are not stored in the body. Since they are excreted when not used, these vitamins should be included in your diet daily. Vitamins A, D, E, and K are fat-soluble and can be stored in the liver.
Deficiencies of the fat-soluble vitamins in a previously well-fed adult may not appear for years. The liver is limited in its capacity to store these vitamins. However taking an excess of vitamins can be harmful to your health. For example, large doses of vitamin A and D have been known to result in headache, nausea, hair loss, disturbance of the menstrual cycle, liver damage, and cellular abnormalities. For some individual’s large intakes of vitamins B and C may also be harmful.
The minimum essential amount of some vitamins required in our daily diet can be very small. For this reason, the Recommended Daily Allowance (RDA) for some vitamins is expressed in International Units (lU). The National Research Council of the National Academy of Sciences advises the Food and Drug Administration as to what the RDA for each vitamin should be. It represents the amount necessary to prevent deficiency symptoms.
There are probably more myths and misunderstandings about vitamins than there are about any other aspect of nutrition. Despite the abundance of foods containing vitamins A and C, many people still don’t have an adequate intake of these vitamins. At the same time, others needlessly consume large quantities of vitamin supplements. This practice is shown by the fact that Americans spend over $500 million annually on vitamin preparations.
Claims have been made about the benefits of large doses of certain vitamins. The question of supplementation in moderate amounts will be discussed below. If you do consume large amounts of some vitamins, or are considering doing so, you should be aware of the pros and cons as indicated by scientific research.
Vitamin B
Five or six vitamins of the B-complex group interact with various enzymes that are important in energy-yielding reactions utilizing carbohydrates and fats. Because of this interaction, many physical fitness enthusiasts and athletes consume large quantities of the vitamin B group in hopes of improving their performances. Yet there is little accepted evidence to support this practice.
Thiamine is sometimes taken as an antidepressant, or to increase the body’s energy. Pantothenic acid is prescribed occasionally for skin disorders and for energy. Again, there is little scientific research to support these claims.
Individuals who drink alcohol excessively do need additional vitamin B supplements. Heavy drinkers often neglect their nutritional needs, and alcohol interferes with the absorption and utilization of vitamin B.
Vitamin C
This is a $100 million-a-year industry. Although many claims have been made about the benefits of its supplementation, scientific evidence to support most of them is lacking. But the connection between vitamin C deficiency and scurvy is accepted as fact by all. Most animals are able to produce vitamin C from sugars within their bodies. But we cannot; we must depend on obtaining it from our food.
The primary function of this vitamin is to assist in the production of collagen. This substance holds cells together, enabling them to maintain the proper physical relationship to each other. It also aids in the formation of scar tissue, necessary for the healing of injured muscles and tendons.
Many individuals take vitamin C supplements and sincerely believe they have fewer colds. It is likely that, in addition to taking a supplement, they become “cold conscious” and monitor their behaviour. That is, they probably try to prevent colds by doing certain other things, such as getting adequate rest, avoiding fatigue, maintaining a good diet, and so on. Vitamin C may play an important role in the prevention and curing of colds. .
Other experiments suggest vitamin C may assist in the prevention of atherosclerosis by acting as a cholesterol suppressant. Guinea pigs with a chronic marginal deficiency of vitamin C have high levels of cholesterol and triglyceride and cholesterol accumulation in tissue and blood vessels. An increased vitamin C intake tends to improve these disorders.
Furthermore, individuals with high levels of cholesterol and triglyceride and a low intake of vitamin C have experienced a decrease in these levels through the long-term administration of vitamin C. In Great Britain, a significantly lower coronary death rate has been reported in regions with a higher intake of vitamin .
Other possible functions of vitamin C, such as its role in the treatment of cancer, are being studied. Vitamin may very well prove to be an extremely important vitamin for treatment of various diseases and disorders, but additional research must be performed before exorbitant claims can be made.
Although too much dietary vitamin C is unlikely to be harmful, large doses of vitamin C supplements might cause: Diarrhea. Nausea. Vomiting. Just as some research supports large doses of vitamin C supplementation. There is some indication that supplementation increases the destruction of vitamin within the body. Scurvy has been observed in individuals who have taken large amounts of vitamin C for a long duration and then returned to a diet with normal amounts.
It could be that the increased rate of vitamin C destruction produced by supplementation persists after supplementation is ceased. High closes of vitamin C may also induce an allergic response which destroys the vitamin. According to another report, individuals who consume 5gm of vitamin C per day had no differences in blood vitamin C levels from those who ate a similar diet but took no supplement. The researchers suggest that either the excess vitamin was destroyed internally or it was eliminated from the body.
In some individuals, doses as low as 500 mg have actually destroyed vitamin B. Which is necessary to prevent red blood cell abnormalities and pernicious anaemia. Yet another problem associated with high vitamin C supplementation is that excess vitamin C in the urine prevents accurate testing for diabetes because it gives a false reading for sugar level. In addition, it is believed that some individuals have experienced gout, haemorrhaging of ulcers, formation of kidney stones, severe diarrhoea, liver abnormalities and enhancement of copper deficiencies as a result of prolonged intake of large vitamin C doses.
Vitamin E
This vitamin is found abundantly in fats and oils.
Vitamin E has been used as a treatment for skin wrinkles, sexual problems, heart disease, aging, increasing physical endurance, and many other things. The belief in its value as a protective agent again staging and for increased physical endurance is derived in part from its unique, but not fully understood, ability to protect body tissues from oxygen breakdown. Still, it is doubtful that vitamin E fulfils the claims that are made for it. In fact, very few of the benefits attributed to vitamin E have been scientifically documented, and many of the claims can be traced to poorly controlled experiments.
Vitamin E has been demonstrated to be of value in the treatment of patients recovering from heart attacks. The vitamin prolongs blood clotting time, allowing the blood to flow more freely. Heart patients and diabetics are cautioned against taking high doses of vitamin E without proper supervision, however. Since it is a strong heart stimulant, high doses can increase the blood pressure of individuals with atherosclerosis or hypertension.
