Vitamins and Supplements

A vitamin is an organic compound required as a nutrient in tiny amounts by an organism. A compound is called a vitamin when it cannot be synthesized in sufficient quantities by an organism, and must be obtained from the diet. Thus, the term is conditional both on the circumstances and the particular organism. For example, ascorbic acid functions as vitamin C for some animals but not others, and vitamins D and K are required in the human diet only in certain circumstances. 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.

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.

History

The value of eating a certain food to maintain health was recognized long before vitamins were identified. The ancient Egyptians knew that feeding liver to a patient would help cure night blindness, an illness now known to be caused by a vitamin A deficiency.The advancement of ocean voyage during the Renaissance resulted in prolonged periods without access to fresh fruits and vegetables, and made illnesses from vitamin deficiency common among ships’ crews.

In 1749, the Scottish surgeon James Lind discovered that citrus foods helped prevent scurvy, a particularly deadly disease in which collagen is not properly formed, causing poor wound healing, bleeding of the gums, severe pain, and death. In 1753, Lind published his Treatise on the Scurvy, which recommended using lemons and limes to avoid scurvy, which was adopted by the British Royal Navy. This led to the nickname Limey for sailors of that organization. Lind’s discovery, however, was not widely accepted by individuals in the Royal Navy’s Arctic expeditions in the 19th century, where it was widely believed that scurvy could be prevented by practicing good hygiene, regular exercise, and by maintaining the morale of the crew while on board, rather than by a diet of fresh food. As a result, Arctic expeditions continued to be plagued by scurvy and other deficiency diseases. In the early 20th century, when Robert Falcon Scott made his two expeditions to the Antarctic, the prevailing medical theory was that scurvy was caused by “tainted” canned food.

Vitamins are essential for the normal growth and development of a multicellular organism. Using the genetic blueprint inherited from its parents, a fetus begins to develop, at the moment of conception, from the nutrients it absorbs. It requires certain vitamins and minerals to be present at certain times. These nutrients facilitate the chemical reactions that produce among other things, skin, bone, and muscle. If there is serious deficiency in one or more of these nutrients, a child may develop a deficiency disease. Even minor deficiencies may cause permanent damage.

In nutrition and diseases

For the most part, vitamins are obtained with food, but a few are obtained by other means. For example, microorganisms in the intestine—commonly known as “gut flora”—produce vitamin K and biotin, while one form of vitamin D is synthesized in the skin with the help of the natural ultraviolet wavelength of sunlight. Humans can produce some vitamins from precursors they consume. Examples include vitamin A, produced from beta carotene, and niacin, from the amino acid tryptophan.

Once growth and development are completed, vitamins remain essential nutrients for the healthy maintenance of the cells, tissues, and organs that make up a multicellular organism; they also enable a multicellular life form to efficiently use chemical energy provided by food it eats, and to help process the proteins, carbohydrates, and fats required for respiration.

Vitamins and Supplements , Vitamins and Supplements  Health, Vitamins and Supplements  Health Latest, Vitamins and Supplements  Health Information, Vitamins and Supplements  Health information, Vitamins and Supplements Health Photo,Exercising for Weight Health photo, Vitamins and Supplements  Health Latest, Vitamins and Supplements Health latest, Exercising for Weight  Health Story, Healthy Minnesota  Health story, Vitamins and Supplements  Video, Vitamins and Supplements  video, Vitamins and Supplements  Health History, Vitamins and Supplements  Health history, Vitamins and Supplements over Picture, history, Vitamins and Supplements  Asia,  Healthy Minnesota  asia, Vitamins and Supplements  Gallery, Exercising for Weight  gallery, Vitamins and Supplements  Photo Gallery, Healthy Minnesota  photo gallery, Vitamins and Supplements  Picture, Vitamins and Supplements  picture, Vitamins and Supplements  Web, Malaysia Health, web Health, web Health picture, video photo, video surgery, gallery, laparoscopy, virus, flu, drug, video, Health Health, calories, photo, nutrition, health video, symptoms, cancer, medical, beating, diet, physical, Training, organic, gym, blister, exercise, weightloss, surgery, spiritual, eating, tips, skin, operation,bf1, Vitamins,  Supplements,  living,  longer