Vitamin

Vitamins are a class of essential nutrients that cannot be synthesized (either at all or in sufficient quantities) by a given organism and must be taken (in trace quantities) with food for that organism's continued good health. Humans require 13 different vitamins. The term vitamin is not used for other classes of essential nutrients including dietary minerals, essential fatty acids or essential amino acids. The name was coined by the Polish biochemist Kazimierz Funk in 1912. Vita in Latin is life and the -amin suffix is short for amine; at the time it was thought that all vitamins were amines. Though this is now known to be incorrect, the name has stuck.

Table of contents

1 Introduction 2 Vitamin deficiency diseases 3 Is vitamin D a real vitamin? 4 Vitamins A and K 5 Names 6 Whatever Happened to Vitamin F? 7 What is Vitamin S? 8 What is Vitamin V? 9 Vitamins T and U 10 New vitamin discovery 11 Non-human vitamins 12 See also 13 External links

Introduction

Vitamins were first recognised by the diseases that occur from a lack of certain foods; for example, the British Royal Navy's observation that limes were effective in preventing scurvy led to the discovery of vitamin C. Vitamins can be divided in two groups by their solubility in water: Water-soluble vitamins\n* Ascorbic acid (vitamin C)\n* Thiamine (vitamin B₁)\n* Riboflavin (vitamin B₂)\n* Niacin or nicotinic acid (vitamin B₃) (also called vitamin P or PP for pellagra prevention)\n* Pantothenic acid (vitamin B₅)\n* Pyridoxine or pyridoxamine (vitamin B₆) \n* Cobalamin (vitamin B₁₂) \n* Biotin (vitamin H)\n* Folic acid (vitamin M) Fat-soluble vitamins\n* Retinol and derivatives (vitamin A) \n* Calciferol (vitamin D)\n* Tocopherol (vitamin E)\n* Naphthoquinone and derivatives (vitamin K) \nFat-soluble vitamins may be stored in the body and can cause toxicity when taken in excess. Water-soluble vitamins are not stored in the body. Unlike food, water, and—for aerobic organisms—air, an organism can survive for some time without vitamins, although prolonged vitamin deficit results in a disease state.

Vitamin deficiency diseases

Several diseases are caused by a lack of adequate vitamin intake. These can become severe, even life-threatening. Some vitamin deficiency diseases include: \n\n\n\n\n\n\n\n\n

Deficient vitamin	Disease
A	night-blindness
B1	beriberi
B2	ariboflavinosis
B12	pernicious anaemia
B3	pellagra
C	scurvy
D	rickets

Other vitamin deficiencies are simply called after the name of the vitamin, such as vitamin K deficiency disease.

Is vitamin D a real vitamin?

Vitamin D is synthesized by the human body, but not always in sufficient quantities. The level of synthesis depends on exposure to sunlight, so in winter and in polar areas there is a greater need to take it, whereas in summer and in equatorial areas it is less necessary. It is generally considered a vitamin, but one that isn't required in some areas and seasons.

Vitamins A and K

Neither vitamin A nor vitamin K is a single chemical substance,\nbut all derivatives fulfill the same functions in organisms (or are converted into the active form by the organism), so taking just one of the derivatives is sufficient for good health. The derivatives differ in chemical structure and level of activity.

Names

Some vitamin names have become obsolete:\n* Vitamin B – actually a complex of several vitamins: B-number, H, and M.\n* Vitamin G – another name for riboflavin (vitamin B₂ ) \nThe usage of names in the format "vitamin letter" and "vitamin letter number" is diminishing.\nThis is especially true for vitamins H, M, B₁, B₂, B₃, and B₅, which are usually called by their proper chemical names. On the other hand, vitamins D and E are still usually called by their symbolic names,\nand A and K don't even have proper chemical names (since they are mixtures of chemicals). The names ascorbic acid and vitamin C are used with similar frequency.

Whatever Happened to Vitamin F?

Vitamin F was the designation originally given to essential fatty acids that the body cannot manufacture. They were "de-vitaminized" because they are fatty acids. Fatty acids are a major component of fats.

What is Vitamin S?

Although there was not originally a Vitamin S, the suggestion has been half-seriously made that salicylic acid may qualify for the criteria needed to be defined as a vitamin, and that in this case the designation "Vitamin S" could be used to describe it.\nVitamin B₁₁ was also called Vitamin S for a while in the 1970s.

What is Vitamin V?

Vitamin V is a name given to Viagra by pop culture, supposedly because of the number of people who take it like a vitamin.

Vitamins T and U

The following are not true vitamins but terms invented by marketeerss and naturopaths\n*Vitamin T\n*Vitamin U

New vitamin discovery

On April 24, 2003 a research team led by Takafumi Kato of the Japanese Institute of Physical and Chemical Research confirmed that pyrroloquinoline quinone (PQQ), a substance originally discovered in 1979, can be categorised as a vitamin. \n

Non-human vitamins

Different organisms need different trace organic substances. The list of vitamins in this article refers to humans. Most mammals need, with few exceptions, the same vitamins (except that most species don't need ascorbic acid in their diet as they synthesize their own). The further apart from mammals a species is, the more diverse the organisms' requirements become. For example, some bacteria need adenine.\nPyrroloquinoline quinone (PQQ) was reported as a vitamin for mice in 2003.

See also

\n*pharmacology

External links

\n* USDA RDA chart in PDF format\n*The lab which discovered the enzyme associated with PQQ\n*REUTERS news item: Japanese Discover First New Vitamin in 55 Years\n*History of vitamin discovery at About.com\n* Vitamins and Minerals Category:Essential nutrients \n\n\n\n\n\n\n\n\n