Ascorbic acid vitamin supplemental

Keto-L-Gulonic acid (2-KLG) is the precursor for Vitamin C (L-Ascorbic acid). Vitamin C is used on a large scale as an antioxidant in food, animal feed, beverages, pharmaceutical formulations, and cosmetic applications. About one half of the vitamin C is used in vitamin supplements and multivitamin preparations, one quarter in food additives, 15 percent in beverages, and 10 percent in animal feed. When ascorbic acid is used in... 

L-Ascorbic acid (vitamin C, ASA) is produced on a scale of 80 kt a-1 worldwide it is used in food supplements, pharmaceutical preparations, cosmetics, as an antioxidant in food processing and a farm animals feed supplement [145]. It is synthesized in vivo by plants and many animals, but not by primates, including Man, or microbes. 

Ascorbic acid, or vitamin C (CgHgOe), is an essential vitamin. It cannot be stored by the body and must be present in the diet. What is the molar mass of ascorbic acid Vitamin C tablets are taken as a dietary supplement. If a typical tablet contains 500.0 mg vitamin C, what amount (moles) and what number of molecules of vitamin C does it contain ... 

Anticoagulants + Dietary supplements Ascorbic acid (Vitamin C)... 

The structure of L-ascorbic acid (vitamin C) resembles that of a monosaccharide. In fact, this vitamin is synthesized both biochemically by plants and some animals and commercially from D-glucose. Humans do not have the enzymes required for this synthesis therefore, we must obtain it in the food we eat or as a vitamin supplement. Approximately 66 million kilograms of vitamin C are synthesized every year in the United States. 

Not surprisingly, the reducing agent ascorbic acid (vitamin C) has certain chemical features common with the reducing sugar glucose. Briefly, observations made on the effect of ascorbic acid supplementation in diabetic individuals, the prooxidant ability of ascorbic acid in vitro, and the ability of ascorbic acid to modify proteins are of interest in the context of the development of diabetic complications. 

Use of an Oral Contraceptive. An estimated 10 to 11 million American women use oral contraceptives. Some have used them for many years prior to discontinuing their use in order to have a child. Researchers have found that these agents change the nutritional needs of some women. The levels of several vitamins and minerals in the blood are known to be, or suspected to be, influenced by the pill. As a result, some oral contraceptive users need increased amounts of certain nutrients in their diets to maintain normal blood levels (a sign of adequate nutrition). Folacin, a B vitamin, is of particular concern since many oral contraceptive users may need a supplement of folacin. In addition, adequate amounts of vitamin C (ascorbic acid), vitamin B-2 (riboflavin), vitamin B-6 (pyridoxine), vitamin B-12, and zinc are needed. 

Other nutrients and their deficiencies that can impact iron status, utilization, or anemia include vitamin A, folate, vitamin B12, riboflavin, and ascorbic acid (vitamin C). Improving iron status can also increase the utilization of iodine and vitamin A from supplements. On the other hand, it is increasingly recognized that simultaneous provision of iron and zinc in supplements may decrease the benefit of one or both of these nutrients. These complex micronutrient interactions and their implications for nutritional interventions are incompletely imderstood but have significant implications for population-based supplementation strategies. 

L-Ascorbic acid is used as a micronutrient additive in pharmaceutical, food, feed, and beverage products, as weU as in cosmetic appHcations. The over-the-counter (OTC) vitamin market is strong, growing in demand, and vitamin C is available in the form of piUs and tablets to supplement the daily diet to maintain peak physical performance. 

Vitamin C, or ascorbic acid, is surely the best known of all vitamins. It was the first vitamin to be discovered (1928), the first to be structurally characterized (1933), and the first to be synthesized in the laboratory (1933). Over 200 million pounds of vitamin C are now synthesized worldwide each year, more than the total amount of all other vitamins combined. In addition to its use as a vitamin supplement, vitamin C is used as a food preservative, a "flour improver" in bakeries, and. an animal food additive. 

Figure 12.3 Effects of 6 weeks vitamin C (ascorbic acid) supplementation In both patients and controls (from Sinclair et al., 1991). Controls "O", no complications group - a complications group. P < 0.001 compared with 0 weeks in all groups. P < 0.05 compared with 3 weeks. P < 0.01 compared with 3 weeks.

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. 

There are no approved pharmacologic treatments for atrophic AMD. The Age-Related Eye Disease Study showed that a supplement containing ascorbic acid 500 mg, vitamin E 400 IU, beta carotene 15 mg, zinc oxide 80 mg, and cupric oxide 2 mg reduced the rate of clinical progression of all types of AMD by 28% in patients with at least intermediate macular degeneration. No benefit was seen in patients with earlier stages of age-related maculopathy however, the duration of the study may have been insufficient to detect this benefit.25... 

The possible involvement of free radicals in the development of hypertension has been suspected for a long time. In 1988, Salonen et al. [73] demonstrated the marked elevation of blood pressure for persons with the lowest levels of plasma ascorbic acid and serum selenium concentrations. In subsequent studies these authors confirmed their first observations and showed that the supplementation with antioxidant combination of ascorbic acid, selenium, vitamin E, and carotene resulted in a significant decrease in diastonic blood pressure [74] and enhanced the resistance of atherogenic lipoproteins in human plasma to oxidative stress [75]. Kristal et al. [76] demonstrated that hypertention is accompanied by priming of PMNs although the enhancement of superoxide release was not correlated with the levels of blood pressure. Russo et al. [77] showed that essential hypertension patients are characterized by higher MDA levels and decreased SOD activities. 

The main sources of vitamin C are green vegetables and citrus fruit. Animal tissue contains vitamin C, mainly in the kidneys and liver. The level of vitamin C in food is rapidly reduced during cooking or storage due to oxidation or water dissolution. It is added to food as an antioxidant (with no specified limit on the level of use) or as a supplement (with a maximum recommended daily intake of 3000mg/day). The forms admitted are L-ascorbic acid (AA), L-ascorbyl 6-palmitate, sodium, calcium, or potassium L-ascorbate [403]. 

Sodium, potassium, and calcium salts of ascorbic acids are called ascorbates and are used as food preservatives. These salts are also used as vitamin supplements. Ascorbic acid is water-soluble and sensitive to light, heat, and air. It passes out of the body readily. To make ascorbic acid fat-soluble, it can be esterified. Esters of ascorbic acid and acids, such as palmitic acid to form ascorbyl palmitate and stearic acid to form ascorbic stearate, are used as antioxidants in food, pharmaceuticals, and cosmetics. 

There is a danger of creating new imbalances by careless use of supplements of vitamins and trace minerals, hormones and drugs. Examples of interaction between trace elements and vitamins include the following vitamin C (ascorbic acid) enhances the biological availability of iron, de-... 

The long-standing interest in the properties of L-ascorbic acid is manifested by the fact that 1146 references related to vitamin C are listed for year 2000 in the PUB MED index in the Internet. The most popular use of L-ascorbic acid is for prevention and treatment of the common cold, but this role remains controversial. In a recent review, the authors conclude that the long-term daily supplementation with large doses of vitamin C does not appear to prevent colds, but there is a modest therapeutic effect on the duration of cold symptoms.369... 

Supplementation with the antioxidant vitamins ascorbic acid (250 mg) and mixed natural tocopherols (50 IU on alternate days) may be beneficial. Higher doses may vitiate the impact of lipid lowering therapy. Other naturally occurring antioxidants such as resveratrol, 3-catechin, selenium, and various carotenoids found in a variety of fruits and vegetables may provide additional antioxidant defense. Homocysteine, which initiates proatherogenic changes in endothelium, can be reduced in many patients by restriction of total protein intake to the amount required for amino acid replacement. Daily supplementation with up to 2 mg of folic acid plus other B vitamins is also recommended. 

Blood plasma of children with cystic fibrosis was found to have decreased TAC (by 16%) in spite of increased concentrations of ascorbic acid, uric acid, and thiol groups (L4). In another study TAC of children with cystic fibrosis was normal, but these children received vitamin supplementation in doses prescribed in international guidelines (a-tocopherol <10 years, 100 mg daily, and >10 years, 200 mg daily retinol 2.5 mg daily ascorbic acid 100-200 mg daily) (M2). Other authors found TAC values for nonhospitalized patients (1.40 0.20 mM) not different from laboratory control values (1.35 0.11 mM), but greater than values for hospitalized patients (1.09 0.17 mM). TAC in CF children correlated positively with anthropometric values (height, weight, body mass index) and pulmonary function (forced expiratory volume in 1 sec), but not with age (L3). 

Previous studies have shown that rats maintained on a vitamin E-deficient diet had higher mortality rate than those of the -supplemented group when subjected to an acute dose of smoking exposure (42). Relatively greater increases in the levels of ascorbic acid, glutathione and related enzymes, glutathione-S-... 

Many cells require media supplemented with complex B vitamins, while other vitamins are presumably supplied by the addition of serum to culture media. Nevertheless, when serum-free media are employed, not only the water-soluble vitamins should be provided, but also the lipid-soluble ones, such as biotin, folic acid, niacin, panthotenic acid, thiamine, and ascorbic acid, as well as the vitamins B12, A, D, E, and K. 

A study on the photoprotective effect of the topical application of 2% vitamin E and 5% vitamin C in humans showed no effect with the application of each substance alone, but an enhanced photo-protective effect after applying vitamins E and C combined, which was attributed to the regeneration of vitamin E by vitamin C.20 This enhanced effect has also been shown with the topical application of a combination of 15% ascorbic acid and 1% a-tocopherol to porcine skin.21 The combined systemic supplementation of vitamins C and E was similarly able to reduce sunburn reactions22 and to increase the minimal erythema dose (MED), a measure for individual photosensitivity, more than supplementation with either vitamin E or vitamin C alone.23,24 An oral supplementation with an anti-oxidative combination of carotenoids (P-carotene and lycopene), vitamin C, vitamin E, selenium, and proanthocyanidins (Seresis , Pharmaton SA, Lugano, Switzerland) also reduced the development and grade of UVB-induced erythema 25... 

Percutaneous absorption of topical vitamin C has already been established for porcine skin increasing to 4- to 40-fold concentrations with repeated application.40,41 These appeared to be even higher than after oral supplementation.27 More detailed investigations in porcine skin showed the following results L-ascorbic acid must be formulated at pH levels less than 3.5 to enter the skin, maximal concentration for optimal percutaneous absorption is 20%, tissue levels are saturated after three daily applications, the half-life of tissue disappearance is about four days. Basically, the penetration of topical vitamin C appears to be critically dependent on formulation characteristics 42... 

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