Vitamins supplements are so common amonge us. We can easily buy them at supermarkets or our local drugs store.
But what are vitamins? and why should we take them?
Nobel Laureate Fritz Lipmann once commented, "Doctors like to prescribe vitamins and millions of people take them, but it requires a good deal of biochemical sophistication to understand why they are needed and how the organism uses them."
Vitamins are essential micronutrients that the body cannot supply in sufficient quantities. They therefore must be obtained from the environment (diet or supplements).
For simplification, vitamins are classified in two groups, according to whether they are water-soluble or fat-soluble. The water-soluble vitamins include vitamin C and the B-complex vitamins; these are considered for the most part relatively non-toxic. The fat-soluble vitamins, A, D, E, K, tend to accumulate in tissues and can be quite toxic at high doses.
What are Enzymes?
Enzymes are the work horses of the body in that they function to facilitate biochemical reactions necessary for activities such as muscle contraction, wound healing, digestion of food, metabolism of carbohydrate, fat and protein, and virtually all the numerous chemical reactions necessary for growth and vitality. The body manufactures approximately 4,000 different enzymes, and 22% of them require a helper molecule, a coenzyme, to carry out their activity. The relatively tiny B vitamin fits snugly into a specific site on the enzyme, much like a ball in a catcher's mitt. This interaction between enzyme and vitamin must be a near perfect fit for the enzyme to be active. Once this reaction is complete, the enzyme, now known as a holoenzyme, can perform work for the cell.
Why should we supplement with vitamins?
Many people, especially as we age, require more nutrients than the diet supplies. Unfortunately, few of us eat the recommended 5-7 servings of fruits and vegetables/day. Scientific evidence continues to accumulate to strengthen the view that vitamin deficiencies are more common than previously thought. It has been estimated that at least 50 human genetic diseases are caused by specific errors in the DNA blueprint, and that these diseases can be corrected or attenuated by taking vitamins several-fold in excess of the recommended daily intake. Other disorders that may be related to genetic factors and vitamin deficiencies include fibromyalgia, chronic fatigue syndrome, migraine, rage, depression, bipolar, and other more minor disorders.
How can megadosing with a particular vitamin make up for some genetic errors?
Vitamin must fit tightly in the pocket of the enzyme for full activity. If an enzyme is produced from a gene containing a genetic error (especially in the formation of the vitamin pocket), the error will most likely affect the ability of the enzyme to bind with the vitamin. This will result in reduced enzyme activity, because the vitamin will not be properly fitted to the enzyme. However, enzymologists working in the laboratory have demonstrated a method to force the vitamin into a pocket of an enzyme with low binding affinity.
The technique involves raising the concentration of the vitamin, thereby increasing the chance of a productive interaction between the vitamin and its binding site (pocket) on the enzyme. This is precisely what is believed to occur in some of the 50 or so known genetic diseases that are corrected or improved by ingestion of megadoses of vitamins. The high doses essentially force the imperfect pocket to pop into the vitamin-binding conformation, thereby creating the active holoenzyme.
Other genetic errors can also interfere with the transport of the vitamin into the cell. For example, a protein known as intrinsic factor is produced by the stomach and functions as a vehicle to carry vitamin B-12 from the intestine into the plasma.
A defect in this factor will also produce a B-12 deficiency, which can be corrected by B-12 injections or high doses of sublingual B-12, both of which by-pass the intrinsic factor block. Since many vitamins have carrier proteins, this type of error is potentially more common than presently realized. Furthermore, stomach acidity is important in vitamin absorption and it is known that some individuals (more common in the elderly) have low vitamin absorption due to abnormal stomach acidity, which again may be corrected by high-dose vitamin therapy.
Vitamins may also serve a role in protecting enzymes from free radical attack. Enzymes are longer-lived when they are in the company of substances they normally work with or bind to, such as the vitamins. The enzyme-bound vitamin affords a shield from free radical attack, as well as promoting a more compact, stable enzyme structure.
How much should one take?
One should avoid taking vitamins in excess of the safe upper limit (UL), unless prescribed by a qualified physician. This safe UL can be several hundred times the recommended daily required intake, yet clearly within the range of the vitamins and minerals present in one multiple vitamin plus a super-B complex/day. A complete list of vitamin-mineral UL can be obtained from the US government National Institutes of Health Office of Dietary Supplements.
The U.S. Government's dietary guideline of 5 to 7 fruits and vegetables per day is widely cited, but often not well understood. Will 5 fruits and no vegetables meet the guideline? What about all veggies and no fruit? Could it be that they mean 5 to 7 fruits AND 5 to 7 vegetables?
Detailed examination of the guidelines reveals that the recommendation is to consume at least 2 servings of fruits and 3 servings of vegetables per day. The rationale is that different fruits and vegetables provide different nutrients.
By Ito Nakamura
Article Source: http://EzineArticles.com/128296
