Vitamins classification

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. 

Morphologic classifications are based on cell size. Macrocytic cells are larger than normal and are associated with deficiencies of vitamin B12 or folate. Microcytic cells are smaller than normal and are associated with iron deficiency whereas normocytic anemia may be associated with recent blood loss or chronic disease. 

The kidney is an endocrine organ. The classification of calcitriol (vitamin D3) as a vitamin is erroneous because the active molecule is synthesized in vivo by a process which usually provides an adequate amount to ensure correct calcium homeostasis. The final step in the biosynthesis of calcitriol (also known as 1,25 cholecalciferol or 1,25... 

Discoverer of glutamic acid in seaweeds. Production of a seasoning of Aji-no-Moto . Introduction oV Umamr into the classification of tastes Discoverer of Orizanin (vitamin B ). 

Ultraviolet light causes a chemical change in dihydrocholesterol to produce cholecalciferol, a precursor of vitamin D. The latter conforms better to the definition of a steroid hormone than a vitamin. Indeed, the classification of vitamin D as a vitamin is an historical accident. The precursor is released from the skin and is further modified in the liver and kidney to form dihydroxycholecalciferol, which is the active form of the hormone (see Chapter 15 for the reactions). It increases calcium absorption from the... 

The classification of vitamin D as a vitamin is largely an historical accident. It conforms much more to the definition of a hormone it is produced in one part of the body and released into the blood to affect other parts of the body in this case, a novel endocrine hormone (Chapter 12). 

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. 

Among the several vitamins in this classification, only vitamin A is present in appreciable quantity as carotenoid provitamin A in citrus (38). No vitamin D has ever been reported in citrus nor any plant vitamin D precursors, such as ergosterol. Several of the sterols present in citrus fruits are reported (39, 40, 41), but they are not related to vitamin D. 

STREET NAMES K, ket, quick, lady K, special K, vitamin K DRUG CLASSIFICATIONS Schedule III, dissociative anesthetic... 

STREET NAMES Vitamin R, West Coast DRUG CLASSIFICATIONS Schedule II, stimulant... 

International classification A23F3/34, A23L2/44, A23F3/00, A23L2/42 This patent covers the addition of Helianthus tuberosus juice to lemon juice or vitamin C to prevent oxidation. After adding plum extract, the mixture is boiled, filtered, and bottled. The drink is free from starch and therefore can be taken by diabetics as a sweetness source. 

Referring to a mechanistic classification of organocatalysts (Seayad and List 2005), currently the two most prominent classes are Brpnsted acid catalysts and Lewis base catalysts. Within the latter class chiral secondary amines (enamine, iminium, dienamine activation for a short review please refer to List 2006) play an important role and can be considered as—by now—already widely extended mimetics of type I aldolases, whereas acylation catalysts, for example, refer to hydrolases or peptidases (Spivey and McDaid 2007). Thiamine-dependent enzymes, a versatile class of C-C bond forming and destructing biocatalysts (Pohl et al. 2002) with their common catalytically active coenzyme thiamine (vitamin Bi), are understood to be the biomimetic roots ofcar-bene catalysis, a further class of nucleophilic, Lewis base catalysis with increasing importance in the last 5 years. 

Anaemias are classified according to the size and haemoglobin content of erythrocytes or to the cause of the condition. In the latter classification bone marrow damage causes aplastic anaemia haemorrhagic and haemolytic anaemia are due to blood loss or damaged red cell membranes respectively, iron deficiency and pernicious anaemia are due to deficiency of iron and vitamin B12 respectively. 

To evaluate nutrition requirements, the reader needs a basic understanding of nutrients and the parameters that affect their needs. Nutrients are chemical substances needed to maintain life which are supplied to the body in food or drinks. The nutrients include vitamins, minerals, carbohydrates, fats, proteins, and water. These classifications of nutrients encompass approximately 45 different chemicals that are involved in every function or structure of the body. Wiile some of these functions that are directly influenced by exercise will be discussed in the subsequent chapters, a complete listing of these functions is beyond the scope of this book. For a more thorouc(i review of nutrient functions, the reader is referred to any one of a number of excellent nutrition references (5-6,15-16). 

Tab. 5.12 Classification and synonyms of coagulation factors, their site of synthesis, vitamin K dependency and half-life (as far as is known)...

Some itamirLS 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 arc ascorbic acid, biotin, folate, niacin, pantothenic acid, riboflavin, thiamin, vitamin B i, and vitamin B 2. The classification is also valuable, as it helps chemists decide on the best way to extract and analyze a particular vitamin in foods and biological tissues. Aside from having some bearing on the path ways 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. 

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