Vitamin C, sources

Ascorbic acid is photosensitive and unstable in aqueous solution at room temperature. During storage of foods, vitamin C is inactivated by oxygen. This process is accelerated by heat and the presence of catalysts. Ascorbic acid concentration in human organs is highest in adrenal and pituitary glands, eye lens, liver, spleen, and brain. Potatoes, citrus fruits, blade currants, sea buckthorns, acerola, rose hips, and red paprika peppers are among the most valuable vitamin C sources [1,2]. 

Maage, A., R. Waagbo, P.-E. Olsson, K. Julshamn and K. Sandnes. Ascorbate-2 sulphate as a dietary vitamin C source for Atlantic salmon (Salmo salar). 2 Effects of dietary levels and immunization on the metabolism of trace elements. Fish Physiol. Biochem. 8 429-436, 1990. 

Rose hip, Cynosbati fructus, is the dried flower bottom of Rosa canina L., family Ro-saceae, deprived of the hairy fruits ( kernels ) from the inside of the drug. The drug contains at least 1% ascorbic acid, and also carotenoids and flavonoids with vitamin P-ef-fect. Rose hips are still used as a vitamin C source in vitamin preparations. 

Hazardous Decomp. Prods. Heated to decomp., emits acrid smoke and irritating fumes Uses Antioxidant, color fixing agent, preservative in foods, pharmaceuticals, baby prods. vitamin C source Regulatory FDA 21CFR 182.3189, GRAS approved for orals Europe listed UK approved BP, EP compliance... 

Definition Potassium salt of ascorbic acid Toxicology Acute and potentially fatal potassium toxicity (hyperkalemia) may occur at 18 g potassium/day in adults contraindicated for those with renal insufficiency Storage Moisture-sensitive Uses Antioxidant in foods potassium and Vitamin C source buffer and stabilizer in folic acid preps. 

Part II Function/Application Index vitamin C source... 

Scruvy and Ascorbic Acid Metabolism 279 Clinicopathology of Scurvy Vitamin C—Sources and Requirements Vitamin C and Metabolism... 

In some studies, especially older ones, an assessment of vitamin C intake from the list of food items appearing in the questionnaire cannot be performed, mostly because the food list was too broad or omitted major vitamin C sources. However, instead of calculating the vitamin C intake quantitatively, a so-called vitamin C index is formed. The vitamin C index usually is a summary figure for the intake of vitamin C-rich food items and can be considered a rough nonquantitative estimate of vitamin C intake. 

Vitamin C source Total mortality Atherosclerotic diseases Cancer Eye diseases... 

Muto N., Terasawa K., Yamamoto 1. Evaluation of ascorbic acid 2-0-a-glucoside as vitamin C source mode of iutestinal hydrolysis and absorption following oral administration. International Journal for Vitamin and Nutrition Research, 62 318 323 (1992). 

Vegetable-fruit group, including a dark-green or deep-yellow vegetable (for vitamin A value) and a citrus fruit or other good vitamin C source, daily. 

A considerable quantity of oil can be extracted from waste material from shelling and processing plants, eg, the inedible kernels rejected during shelling and fragments of kernels recovered from shells. About 300 t of pecan oil and 300—600 t of English walnut oil are produced aimuaHy from such sources. The oil is refined and used for edible purposes or for the production of soap the cake is used in animal feeds (see Feeds and feed additives). Fmit-pit oils, which closely resemble and are often substituted for almond oil, are produced on a large scale for cosmetic and pharmaceutical purposes (143). For instance, leaves, bark, and pericarp of walnut may be used to manufacture vitamin C, medicines, dyes and tannin materials (144). 

One excellent UV protector for foods is PABA, a B vitamin. Likewise, many of the same antioxidants we ingest as health supplements—such as vitamin C and a similar chemical, erythorbic acid vitamin E and lecithin, a source of the important nutrients choline and inositol—occur naturally in food. 

Vitamin C occurs as L-ascorbic acid and dihydroascorbic acid in fruits, vegetables and potatoes, as well as in processed foods to which it has been added as an antioxidant. The only wholly undisputed function of vitamin C is the prevention of scurvy. Although this is the physiological rationale for the currently recommended intake levels, there is growing evidence that vitamin C may provide additional protective effects against other diseases including cancer, and the recommended dietary allowance (RDA) may be increased in the near future. Scurvy develops in adults whose habitual intake of vitamin C falls below 1 mg/d, and under experimental conditions 10 mg/d is sufficient to prevent or alleviate symptoms (Bartley et al., 1953). The RDA is 60 mg per day in the USA, but plasma levels of ascorbate do not achieve saturation until daily intakes reach around 100 mg (Bates et al., 1979). Most of the ascorbate in human diets is derived from natural sources, and consumers who eat five portions, or about 400-500 g, of fruits and vegetables per day could obtain as much as 200 mg of ascorbate. 

Pectin is found in apples and in the white membrane that surrounds the sections of oranges, grapefruits, or other citrus fruits, as well as in several other sources. Powdered pectin made from apple cores is also available, but scientists have found that eating apples or citrus fruit has a much better effect on lowering blood cholesterol levels than eating powered pectin does. They believe eating the whole fruit is better because the body also needs vitamin C to convert cholesterol into bile acids. Fruits contain vitamin C, or ascorbic acid, but the powdered pectin does not. 

Biosyntheses of hexuronic acids and L-ascorbic acid in plants and animals are closely related. Hexuronic acids, L-ascorbic acid, and L-tartaric acid (a possible precursor of dihydroxyfumaric acid) commonly occur together in plants. If a rat is given chloretone (an antispasmodic), both L-ascorbic acid and D-glucuronic acid are excreted in increased quantity.244 Unlike humans, rats can synthesize their own vitamin C, and are therefore independent of outside sources. Here, D-glucose and D-galactose can be utilized, but not D-mannose. 

Mango fruit is a rich source of vitamin C and carotenoids, some of which function as provitamin A (Siddappa and Bhatia 1954 Thomas 1975, Yahia and others... 

Some types of mushrooms contain moderate quantities of good-quality protein and are good sources of dietary fiber, vitamins C and B, and minerals (Breene 1990). Extensive clinical studies have demonstrated that some species have medicinal and therapeutic value, by injection or oral administration, in the prevention/treatment of... 

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