Vitamins water-soluble vitamins

Ascorbic acid as a water-soluble vitamin (vitamin C) is an essential component in the human diet. As one of many anti-oxidants (vitamin E and 3-carotene are examples of fat-soluble anti-oxidants), ascorbic acid is required for the growth and repair of tissues in all parts of the body. It is necessary to form collagen, an important protein used to make skin, scar tissue, tendons, ligaments, and blood vessels. 

Water-soluble vitamins (vitamin Bi, vitamin Bg, vitamin B12, and vitamin C) in Kombucha drink (a curative liquor) were separated by TLC on silica gel plates with water as the solvent. The plates were visually examined under UV light at 254- and 366-nm wave-g lengths. The four vitamins were identified and determinec by comparing the Rf values with the reference values (vitamin Bi, 0.21 vitamin Bg, 0.73 vitamin B12,0.34 anc vitamin C, 0.96). ... 

Thiamine (THYE-uh-min) is the water-soluble vitamin, vitamin Bx. It is also known as 3-(4-Amino-2-methylpyrimidyl-... 

Vitamins are the foodstuff components most often quantified using fluorimetric means. There are several official fluorimetric methods for the determination of three water-soluble vitamins vitamin Bi (thiamine) (AOAC 942.23 and 957.17), B2 (rib-oflavine) (AOAC 970.65 and 981.15), and C (ascorbic acid) (AOAC 984.26). Thiamine is determined by oxidation to fluorescent thiochrome with alkaline hexacyanoferrate(III) or an alternative oxidant (Figure 1). The method is quite simple, reproducible, and selective and provides good recoveries. Many LC methods for thiamine determination in foods have... 

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. 

Water-Soluble Vitamins. Vitamin G (ascorbic acid) functions in the formation of collagen, wound healing, metabolic functions, and other roles. Foods high in vitamin G include citrus fruits, strawberries, cantaloupe, and cruciferous vegetables. B vitamins are important in energy metabolism. Thiamin (Bj) is called the antineuritic vitamin. Riboflavin (B ), rarely deficient in the diet, is found most abundantly in milk and dairy products. Niacin (Bj) is prevalent in meats, poultry, fish, peanut butter, and other foods. Other major B vitamins include folic acid (B ), B, and Bj2-... 

B vitamins. Among the 13 vitamins, B vitamins are eight water-soluble vitamins (vitamin Bp thiamine vitamin B2 riboflavin vitamin B3 niacin vitamin B5 pantothenic acid vitamin Bg pyridoxine, pyridoxal or pyridoxamine vitamin B7 biotin vitamin B9 folic acid or folate and vitamin B cyanoco-balamin). Folate and vitamins Bg and B12 have joint effects on homocysteine. Cardiovascular disease. Cardiovascular disease (CVD) is a group of disorders of the heart and blood vessels and includes coronary heart disease, cerebrovascular disease, peripheral arterial disease, rheumatic heart disease, congenital heart disease (malformations of heart structure existing at birth) and deep vein thrombosis and pulmonary embolism. 

In contrast to other water-soluble vitamins, vitamin Bjj is not excreted quickly in the urine, but rather accumulates and is stored... 

Excesses of water-soluble vitamins (vitamin C and the vitamin B complex) are not stored in the body to any great extent, so toxicities from food sources of these nutrients are rare. However, people who take very large doses (megadoses) in the form of supplements run the risk of dangerous, druglike effects. 

This refers to an excessive intake of certain vitamins. The best known vitamin toxicities are those which result from vitamin A (known as hypervitaminosis A) and vitamin D (known as hypervitaminosis D), because (1) these vitamins are fat-soluble, (2) small amounts of them have strong effects, and (3) they tend to accumulate in the liver. Toxic effects do not occur so readily with vitamins E and K, which are also fat-soluble, unless high potency supplements are taken. Excesses of water-soluble vitamins (vitamin C and the vitamin B complex) are not stored in the body to any great extent, so toxicities from food sources of these nutrients are rare. However, people who take very large doses (mega-... 

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... 

Description of Method. The water-soluble vitamins Bi (thiamine hydrochloride), B2 (riboflavin), B3 (niacinamide), and Be (pyridoxine hydrochloride) may be determined by CZE using a pH 9 sodium tetraborate/sodlum dIhydrogen phosphate buffer or by MEKC using the same buffer with the addition of sodium dodecyl-sulfate. Detection Is by UV absorption at 200 nm. An Internal standard of o-ethoxybenzamide Is used to standardize the method. 

Of the water-soluble vitamins, intakes of nicotinic acid [59-67-6] on the order of 10 to 30 times the recommended daily allowance (RE)A) have been shown to cause flushing, headache, nausea, and moderate lowering of semm cholesterol with concurrent increases in semm glucose. Toxic levels of foHc acid [59-30-3] are ca 20 mg/d in infants, and probably approach 400 mg/d in adults. The body seems able to tolerate very large intakes of ascorbic acid [50-81-7] (vitamin C) without iH effect, but levels in excess of 9 g/d have been reported to cause increases in urinary oxaHc acid excretion. Urinary and blood uric acid also rise as a result of high intakes of ascorbic acid, and these factors may increase the tendency for formation of kidney or bladder stones. AH other water-soluble vitamins possess an even wider margin of safety and present no practical problem (82). 

Along with increasing evidence of health benefits from consumption of vitamins at levels much higher than RE) A recommendations comes concern over potential toxicity. This topic has been reviewed (19). Like all chemical substances, a toxic level does exist for each vitarnin. Traditionally it has been assumed that all water-soluble vitamins are safe at any level of intake and all fat-soluble vitamins are toxic, especially at intakes more than 10 times the recommended allowances. These assumptions are now known to be incorrect. Very high doses of some water-soluble vitamins, especially niacin and vitamin B, are associated with adverse effects. In contrast, evidence indicates that some fat-soluble micronutrients, especially vitamin E, are safe at doses many times higher than recommended levels of intake. Chronic intakes above the RDA for vitamins A and D especially are to be avoided, however. 

Ascorbic acid commonly known as vitamin C, is one of the most important water soluble vitamins. Ascorbic acid is involved in many biological processes and it is an essential compound in the human diet [1]. The determination of ascorbic acid has gained increase significance in pharmaceutic, clinical, and food applications. So far, different methods have been developed for determination of ascorbic acid [2, 3]. 

Water-Soluble Thiamine (vitamin Bj) Thiamine pyrophosphate... 

K. Johansen and P. O. Edlund, Determination of water-soluble vitamins in blood and plasma by coupled-column liquid clrromatography , 7. Chromatogr. 506 471-479 (1990). 

Vitamin C is water-soluble (hydrophiLic) vitamin A is fat-soluble (hydrophilic). 

Bile acid sequestrants may interfere with die digestion of fats and prevent die absorption of die fat-soluble vitamins (vitamins A, D, E, and K) and folic acid. When die bile acid sequestrants are used for long-term therapy, vitamins A and D may be given in a water-soluble form or administered parenterally. If bleedingtendencies occur as die result of vitamin K deficiency, parenteral vitamin K is administered for immediate treatment, and oral vitamin K is given for prevention of a deficiency in the futum... 

Gliszczyhska-Swigl, A. (2006). Antioxidant activity of water soluble vitamins in the TEAC (trolox equivalent antioxidant capacity) and the FRAP (ferric reducing antioxidant power) assays. Food Chemistry, Vol.96, No.l, (May 2006), pp. 131-136, ISSN 0308-8146. 

The water-soluble B vitamins supply important components of numerous coenzymes. Many coenzymes contain, in addition, the adenine, ribose, and phosphoryl moieties of AMP or ADP (Figure 7-2). Nicotinamide and riboflavin are components of the redox coenzymes... 

The water-soluble vitamins comprise the B complex and vitamin C and function as enzyme cofactors. Fofic acid acts as a carrier of one-carbon units. Deficiency of a single vitamin of the B complex is rare, since poor diets are most often associated with multiple deficiency states. Nevertheless, specific syndromes are characteristic of deficiencies of individual vitamins, eg, beriberi (thiamin) cheilosis, glossitis, seborrhea (riboflavin) pellagra (niacin) peripheral neuritis (pyridoxine) megaloblastic anemia, methyhnalonic aciduria, and pernicious anemia (vitamin Bjj) and megaloblastic anemia (folic acid). Vitamin C deficiency leads to scurvy. 

The water-soluble vitamins of the B complex act as enzyme cofactors. Thiamin is a cofactor in oxidative... 

Under aqueous conditions, flavonoids and their glycosides will also reduce oxidants other than peroxyl radicals and may have a role in protecting membranal systems against pro-oxidants such as metal ions and activated oxygen species in the aqueous phase. Rate constants for reduction of superoxide anion show flavonoids to be more efficient than the water-soluble vitamin E analogue trolox (Jovanovic et al, 1994), see Table 16.1. 

Micronutrients (mg/100 g) Water-soluble vitamins B-vitamins Thiamin 2.65 3.64 2.00... 

Vitamin E can also inhibit nitrosation reactions but the mechanisms may be somewhat different than those for vitamin C (55,56). Of course, vitamin C is water soluble while vitamin E... 

R. Schonwitz and H. Ziegler, Exudation of water soluble vitamins and some carbohydrates by intact roots of maize seedlings Zea mays L.) into a mineral nutrient solution. Z. Planzenphysiol. 107 1 (1982). 

W. R. Streit, C. M. Joseph, and D. A. Phillips, Biotin and other water-soluble vitamins are key growth factors for alfalfa rhizosphere colonization by Rhizobium meli-loti 1021. Molec. Plant Microbe Interact. 5 330 (1996). 

Water-soluble vitamins removed by hemodialysis (HD) contribute to malnutrition and vitamin deficiency syndromes. Patients receiving HD often require replacement of water-soluble vitamins to prevent adverse effects. The vitamins that may require replacement are ascorbic acid, thiamine, biotin, folic acid, riboflavin, and pyridoxine. Patients receiving HD should receive a multivitamin B complex with vitamin C supplement, but should not take supplements that include fat-soluble vitamins, such as vitamins A, E, or K, which can accumulate in patients with renal failure. 

The ADA does not recommend low-carbohydrate diets in diabetes management. Although carbohydrates are a primary contributor to post-meal glucose levels, they are also an important source of energy, water-soluble vitamins, minerals, and fiber. Thus, the ADA recommends that carbohydrate intake consists of 45% to 65% of total calories. 

No significant quantity of the macronutrients nor of the vitamins for which U.S. Recommended Dietary Allowance (RDA) have been established can be obtained from the consumption of a cup of tea.110 The water-soluble B vitamins present are easily extractable. Eight percent extractabil-ity for a representative black tea blend is assumed.110... 

A thorough discussion of the mechanisms of absorption is provided in Chapter 4. Water-soluble vitamins (B2, B12, and C) and other nutrients (e.g., monosaccharides, amino acids) are absorbed by specialized mechanisms. With the exception of a number of antimetabolites used in cancer chemotherapy, L-dopa, and certain antibiotics (e.g., aminopenicillins, aminoceph-alosporins), virtually all drugs are absorbed in humans by a passive diffusion mechanism. Passive diffusion indicates that the transfer of a compound from an aqueous phase through a membrane may be described by physicochemical laws and by the properties of the membrane. The membrane itself is passive in that it does not partake in the transfer process but acts as a simple barrier to diffusion. The driving force for diffusion across the membrane is the concentration gradient (more correctly, the activity gradient) of the compound across that membrane. This mechanism of... 

Modern Analytical Methodologies in Fat- and Water-Soluble Vitamins. Edited by Won O. Song, Gary R. Beecher, and Ronald R. Eitenmiller... 

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