A vitamin is defined as an organic compound and a vital nutrient that an organism requires in limited amounts. An organic chemical compound (or related set of compounds) is called a vitamin when the organism cannot synthesize the compound in sufficient quantities, and must be obtained through the diet; thus, the term "vitamin" is conditional upon the circumstances and the particular organism. For example, ascorbic acid (vitamin C) is a vitamin for humans, but not for most other animal organisms. Supplementation is important for the treatment of certain health problems, but there is little evidence of nutritional benefit when used by otherwise healthy people.
All natural vitamins are organic food substances found only in living things, that is, plants and animals. With few exceptions, the body cannot manufacture or synthesize vitamins. They must be supplied by the diet or in dietary supplements. Vitamins are essential to the normal functioning of our bodies. They are necessary for growth, vitality, health, general well being, and for the prevention and cure of many health problems and diseases.
Vitamins are classified by their biological and chemical activity, not their structure:
Thus, each "vitamin" may refer to several vitamer compounds that all show the biological activity associated with a particular vitamin. Such a set of chemicals are grouped under an alphabetized vitamin "generic descriptor" title, such as "vitamin A," which includes the compounds retinal, retinol, and many carotenoids. Vitamers are often inter-converted in the body. The term vitamin does not include other essential nutrients such as dietary minerals, essential fatty acids, or essential amino acids, nor does it encompass the large number of other nutrients that promote health but are otherwise required less often.
In humans there are 13 vitamins: 4 fat-soluble (A, D, E and K) and 9 water-soluble (8 B vitamins and vitamin C).
Water-soluble vitamins dissolve easily in water, and in general, are readily excreted from the body, to the degree that urinary output is a strong predictor of vitamin consumption. Because they are not readily stored, consistent daily intake is important. Many types of water-soluble vitamins are synthesized by bacteria.
Fat-soluble vitamins are absorbed through the intestinal tract with the help of lipids (fats). Because they are more likely to accumulate in the body, they are more likely to lead to hypervitaminosis than are water-soluble vitamins. Fat-soluble vitamin regulation is of particular significance in cystic fibrosis.
Important for vision, reproductive function, and normal cell reproduction. Beta-carotene, a precursor to Vitamin A, helps to fight disease-causing free radicals. Vitamin A is found in milk products, organ meats, and fish oils. Beta-carotene is found in colorful vegetables, such as carrots, broccoli, spinach, and sweet potatoes.
Vitamin A Sources:
Vitamin B-1 (Thiamin) processes carbohydrates into energy and is necessary for nerve cell function. Breads and cereals are often fortified with thiamin, though it is also found in whole grains, fish, lean meats, and dried beans.
Thiamine (vitamin B1) Sources:
Vitamin B-2 (Riboflavin) - Helps the production of red blood cells and is important for growth.
Vitamin B-3 (niacin) - Helps control cholesterol, processes alcohol, maintains healthy skin, and converts carbohydrates to energy.
Niacin (vitamin B3) Sources:
Vitamin B-5 (pantothenic acid) serves several bodily functions, such as converting fats to energy and synthesizing cholesterol.
Pantothenic acid (vitamin B5) Sources:
Vitamin B-6 (pyridoxine) is important in the production of hormones such as serotonin, dopamine, and melatonin, as well as for processing amino acids.
Pyroxidine (vitamin B6) Sources:
A crucial component of DNA replication and nerve cell regulation. It is found in milk products, poultry, meat, and shellfish.
Vitamin B12 Sources:
Animal sources of vitamin B12 are absorbed much better by the body than plant sources
Important in wound healing and acts as an antioxidant. It also helps the body absorb iron. It's found in citrus fruits, potatoes, and greens.
Vitamin C Sources:
Helps the body absorb calcium, which creates healthy bones and teeth. The body can synthesize Vitamin D after exposure to sunshine, but it can also be found in fortified milk products and cereals, as well as in fish.
Vitamin D Sources:
Helps to combat free radicals, which can damage our cells. It's found in nuts and seeds, green leafy vegetables, corn, asparagus, and wheat germ.
Vitamin E Sources:
What makes the blot clot. While our bodies produce some Vitamin K, it can also be found in vegetables like cauliflower and cabbage.
Vitamin K Sources:
Deficiencies of vitamins are classified as either primary or secondary.
People who eat a varied diet are unlikely to develop a severe primary vitamin deficiency.
In contrast, restrictive diets have the potential to cause prolonged vitamin deficits, which may result in often painful and potentially deadly diseases.
Dietary supplements, often containing vitamins, are used to ensure that adequate amounts of nutrients are obtained on a daily basis, if optimal amounts of the nutrients cannot be obtained through a varied diet. Scientific evidence supporting the benefits of some dietary supplements is well established for certain health conditions, but others need further study.
The best way to get enough vitamins is to eat a balanced diet with a variety of foods. In some cases, you may need to take a daily multivitamin for optimal health. However, high doses of some vitamins can make you sick.
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