What are these wonder micronutrients that your body cannot produce all by itself but needs them badly in trace quantities? They are called vitamins. Vitamins are not synthesized or produced by the body so they need to be obtained by humans through the food they eat. Humans need 13 vitamins to maintain good health.

It is important to know that there are two kinds of vitamins for safety purposes for one of them might cause toxicity when taken in large dosages. Here are the two types of vitamins, the vitamins included on each type, their function and sources.

Fat-soluble vitamins are dietary supplements that may be absorbed by the body's fat. This absorption means that these vitamins can stay in the body, particularly in the liver, as long as they want. Because they are stored, they don't need to be replaced daily. These fat-soluble vitamins include vitamin A, D, E and K.

Vitamin A works for healthy eyes, maintenance of a good complexion and prevents aging. Sources of this vitamin are vegetables, kidney, liver and milk. When the body lacks this vitamin, nigh blindness, xerophthalmia or no tear secretion, phrynoderma or toad skin, retarded growth and low resistance against infection may occur on the person.

Vitamin D helps in the burning of calcium and phosphorus, and proper development of bones and teeth. It is commonly found in liver, dairy food and eggs. Deficiency of this vitamin will cause rickets or brittle bones, osteomalacia or softening of the bones, and poor development of teeth.

Vitamin E aids in the proper functioning of the reproductive organs, acts as an antioxidant and also helps in the maintenance of a good skin. Sources of vitamin E are green leafy vegetables, milk, butter and meat. Deficiency of this vitamin may result to abnormal development of the fetus and infertility.

Vitamin K is for the proper functioning of liver and normal clotting of blood. Vitamin K could be taken from green leafy vegetables and soybeans. A person lacking this vitamin may be afflicted with hemorrhages.

Water-soluble vitamins are micronutrients that are not stored in the body and must be replaced in a regular basis. They are dissolved in water and eliminated in urine. These vitamins are easily washed out or removed during food preparation. Vitamins considered as water-soluble are the B-complex vitamins and vitamin C.

The B-complex vitamins include thiamin, riboflavin, niacin, pantothenic acid, folate, B6 and biotin. They support the body in maintaining a good eyesight, healthy skin, normal appetite, a healthy nervous and circulatory system. Sources of these vitamins include enriched grain products like white rice, breakfast cereals, pasta, breads and white flour. Deficiency of these vitamins may result to pernicious anemia, pellagra, beri-beri and other B-complex related deficiency diseases. Vitamin C or ascorbic acid is another water-soluble vitamin that helps in the wound healing process, production of brain hormones and maintenance of blood vessels, teeth and bones. Ascorbic acid is from citrus fruits and other vegetables. If one lacks this vitamin, he may succumb to hemorrhages, rough, dry skin, scurvy, sore joints and bones and increased risk to infections.

These dietary supplements must always be taken with precaution and must follow a certain recommended daily allowance to ensure safety and effectiveness. Morag Bevan is well known for her "secret" Health reports. Her website can be found at http://www.rhhealth.com