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Vitamin Facts You Need To Know
By: Ofelia B. Mutia, M.S.,R.D.,L.D.
Vitamins are organic nutrients that do not provide calories for energy. They are needed in the diet in tiny amounts. Vitamins in foods come in the form of precursors, also known as provitamins. Precursors are compounds that can be converted into active vitamins. Once eaten, the body changes them chemically into active vitamins. Vitamins do not make you strong nor do they provide you with energy. However, they help other nutrients do their work properly. For example, Vitamin B1 called Thiamin helps in the breakdown of carbohydrate for energy. Other vitamins, such as Niacin and Riboflavin help in the breakdown of protein and fat to produce glucose for energy.
There are two classes of vitamins:
1. Fat-Soluble Vitamins: A, D, E and K
2. Water-Soluble Vitamins: C and the B Complex group
Fat-Soluble Vitamins
These are classified into four groups: Vitamin A, D, E, and K. These vitamins are found in fats and oils. Unlike the water-soluble vitamins, fat-soluble vitamins are not easily excreted by the body. Instead they are abundantly stored in the liver and adipose tissue of the body. Many scientists believe that because of the fat components of these vitamins, and because they are found in abundant supply in the body, that this may be one of the reasons why some people can survive for numerous days without eating.
For the most part, fat-soluble vitamins come from fish oils and plant oils. As mentioned above, once eaten and absorbed in the intestinal tract, these kinds of vitamins are not easily excreted because they are stored in the liver and fatty tissues. Some may be lost during digestion, or with undigested fats in conditions such as fat malabsorption.
The risk for toxicity, especially with Vitamin A, D, and K are much more dangerous than you might imagine. Some researchers have indicated that vitamin pills are characterized as a drug rather than a vitamin and can reach toxic levels if taken in excessive amounts. Therefore, it is important for you to know your recommended dietary allowance (RDA). The Recommended Dietary Allowance has been established to guide you in the safe and appropriate amount to take.
Water-Soluble Vitamins
These vitamins are found in the watery space in foods as well as freely circulated in the fluid space of the body. They are also carried in the bloodstream. However, unlike the fat-soluble vitamins, they are reported to be the least likely to reach toxic levels. This is because under normal conditions, these vitamins are easily excreted in the urine when the blood levels reach their peak. The only exception to this is Vitamin B12, which will be explained in the B12 article.
Water-soluble vitamins are classified into B Vitamins, Vitamin C, Folacin or Folic Acid, Biotin, and Pantothenic Acid. These vitamins are considered as "energy drivers." This is because they play a very important part in the release of energy from the breakdown of foods by acting as part of enzymes, or acting as coenzymes. For example, when Carbohydrates are broken down into glucose for energy, certain enzymes are required to complete the process. However, in order for the enzymes to work, coenzymes must help.
Being catalysts, enzymes have the ability to release energy from the breakdown of Carbohydrate, Fat and Protein. However, that action also requires the help of coenzymes which are mostly performed by B Vitamins. B Vitamins are also described as "cell multipliers" because they help in the reproduction of red blood cells and cells in the linings of the stomach and intestines. Such cells play very important roles in delivering energy to all tissues of the body.
Under normal conditions, these vitamins are easily excreted in the urine when eaten in excess. For this reason, use of mega-doses of vitamin supplements of this kind is unnecessary and a waste of money. However, some of these vitamins can stay in the muscle tissues for several months until your body fluids pick them up (via the bloodstream) for excretion. Under normal circumstances, vitamins from food sources are better absorbed than supplemental (commercialized) vitamin pills.
It is important to keep vitamins intact by properly handling and preparing food, because some vitamins in food are lost during preparation and processing. In commercialized products, vitamins and minerals are put back in the food through enrichment or a fortification process. If you eat a well-balanced meal, there is no need to take mega-doses of supplemental vitamins, unless your medical condition identifies a severe vitamin deficiency. For those who are already eating a well-balanced meal, do not panic if one day, your food intake is short-changed. The liver can quickly compensate for that temporary shortage by releasing its stored vitamins and minerals and then later replenish that storage when food is eaten.
To check the effectiveness of a vitamin pill, try submerging one pill in a half cup of vinegar until it is completely dissolved - if it takes longer than an hour, this means that the pill may not be efficiently absorbed in the body.
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