Vitamins, classification water soluble

Some vitamins are water soluble, while others are fat soluble. This classification is valuable as it indicates whether the vitamin is likely to be absorbed similarly to lipids or like other water-soluble nutrients. The fat-soluble vitamins are A, D, E, and K. The water-soluble vitamins are ascorbic acid, biotin, folate, niacin, pantothenic acid, riboflavin, thiamin, vitamin B5, and vitamin B12. The classification is also valuable, as it helps chemists dedde on the best way to extract and analyze a particular vitamin in foods and biological tissues. Aside from having some bearing on the pathways of absorption and distribution throughout the body, the question of whether a particular vitamin is fat soluble or water soluble has little or no relevance to its function in the body. 

Their solubility either in fat or water is the major criterion for the classification of the 13 chemicals, or groups of chemicals, identified as vifamins. The eight B vitamins and vitamin C are water soluble. Except for some B vitamins, the possibilities for their storage are very limited and they have to be consumed almost on a daily basis. Vitamins A, D, E and K are fat-soluble and are thus found in fat-containing foods. As these vitamins are at least to some extend stored in body fat, daily consumption is not needed. Some general information on the water soluble and fat-soluble vitamins are summarized in Tables 1 and 2, respectively. 

Vitamins are classifed as either water-soluble or fat-soluble. Use SpartanView to examine electrostatic potential maps of vitamin A, vitamin Bg, vitamin C, and vitamin E, and determine which class each vitamin belongs to. 

The order of vitamins in this chapter follows the classical classification-based solubility fat soluble and water soluble. This classification originated before there was any understand-... 

Classification of vitamins into fat-soluble and water-soluble groups reflects the history of their discovery. This grouping is still useful, despite the lack of chemical relatedness within each class, because it mirrors other underlying similarities. 

Vitamins are a chemically and functionally inhomogeneous group of biomolecules. As a gross classification distinction is usually made between (1) fat-soluble and (2) water-soluble vitamins. Owing to their insolubility in water the fat-soluble vitamins A, D, E, and K can be accumulated in fat tissue and excessive intake causes hypervitaminoses. The water-soluble vitamins - vitamin Bj, vitamin B2, niacin, vitamin Bg, folic acid, pantothenic acid, biotin, vitamin B12, and ascorbic acid - can generally only be stored in a small amount and intake exceeding actual need is excreted in the urine. 

Vitamin classification is initially based on fat solubility—i.e., A, D, E, and K— versus water solubility—i.e., C, folic acid, nicotinic acid, and nicotinamide (B3), B, B2, Bs, biotin, B,2, and pantothenic acid. DeLeenheer et al. (1985, 1992) edited two valuable treatises on modern chromatographic analysis of vitamins. Two tables have been compiled in this chapter with information on the chemical terms for vitamins and their derivatives, vitamin function, sources of vitamins and recent selected references containing TLC information. Table 19.1 summarizes pertinent information on the fat-soluble vitamins and Table 19.2 does the same for the water-soluble vitamins. 

Nomenclature and Classification Fat-Soluble vs Water-Soluble Vitamins Vitamin B Complex Vitaminlike Substances Determination of the Vitamins in Food Biological (Animal) Assay Microbiological Assay Chemical Assay Physical Assay Human Assay... 

Classification of Vitamins. Vitamins are classified as either fat soluble or water soluble. This rather superficial classification is still useful because it indicates the best food source of a vitamin. Table XIX presents the principal vitamins several factors whose significance is still debated (inositol, choline) have not been included. 

Lipids are bioorganic substances related to fatty acid esters and include a variety of compounds such as glycerol esters, waxes, phosphoglycerides, sphingolipids, natural hydrocarbons, some vitamins, etc. This diversity of compounds is explained by the fact that initially the term lipids was used to describe natural bioorganic substances soluble in hydrocarbons and insoluble in water. Lipids include both small molecules and polymeric materials. Because some simple lipids are not polymeric, their pyrolysis will be discussed only to the extent of being associated with the pyrolysis of complex lipids. However, non-polymeric lipids are commonly associated with polymeric ones, and pyrolytic techniques were frequently applied on the whole lipid without separation for purposes such as classification or identification of microorganisms based on the pyrolysis pattern of their lipids [1]. 

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