Vitamin C, dietary

Mason P. Vitamin C. Dietary Supplements, 2nd edn. London Pharmaceutical Press, 2001 227—233. 

Nutrient Content high in prebiotic fiber, antioxidant vitamin C, dietary minerals... 

Nutrient Content high in antioxidant vitamin C, dietary minerals Phytochemical Content high in polyphenols, including resveratrol and the richest content of anthocyanins yet described for fruits Color Code red-purple-black... 

Blackberry signature nutrients stand out as particularly enriched vitamin C, dietary fiber, manganese, and vitamin K are all at about 20 percent of daily value per serving and are combined with a broad profile of other nutrients in good content. A hidden quality not enjoyed by everyone is the presence of nutrient-laden seeds throughout each berry. If you don t mind the crunchy surprise in each bite, make sure to chew these seeds well to gain the maximum yield of their nutrient contents. 

Al. Abt, A. F., Schuching, S. von, and Roe, J. H., Connective tissue studies. III. Ascorbic acid, collagen and hexosamine distribution and histology of connective tissue in scars produced in guinea pigs on various vitamin C dietary levels following wounding by abdominal incision. J. Nutrition 70, 427-437 (1960). 

In this period, the empirical healing of certain diseases by foods was estabUshed. Examples (3) were the treatment of night blindness (vitamin A deficiency) with hver ia many cultures over centuries, of beriberi (vitamin deficiency) by use of unpoHshed rice by the Japanese navy, of scurvy (vitamin C deficiency) by citms fmits ia the British navy or piae needle extracts by North American natives, and pellagra (niacia deficiency) by a dietary shift away from corn-based foods ia many countries. Other, nondietary empirical treatments iavolved, eg, exposure of children ia northern latitudes to sunlight to cute tickets (vitamin D deficiency) (4). 

Brewers and bakers dried yeasts are used as dietary supplements. They contribute some protein and trace minerals, and some B vitamins, but no vitamin C, vitamin B 2 or fat-soluble vitamins. The glucose tolerance factor (GTE) of yeast, chromium nicotinate, mediates the effect of insulin. It seems to be important for older persons who caimot synthesize GTE from inorganic dietary chromium. The ceU wall fraction of bakers yeast reduces cholesterol levels in rats fed a hypercholesteremic diet. 

Scurvy results from a dietary vitamin C deficiency and involves the inability to form collagen fibrils properly. This is the result of reduced activity of prolyl hydroxylase, which is vitamin C-dependent, as previously noted. Scurvy leads to lesions in the skin and blood vessels, and, in its advanced stages, it can lead to grotesque disfiguration and eventual death. Although rare in the modern world, it was a disease well known to sea-faring explorers in earlier times who did not appreciate the importance of fresh fruits and vegetables in the diet. 

In addition to the hazards of weather, participants in early polar expeditions often suffered from scurvy, caused by a dietary vitamin C deficiency. 

The complex series of events in collagen maturation provide a model that illustrates the biologic consequences of incomplete polypeptide maturation. The best-known defect in collagen biosynthesis is scurvy, a result of a dietary deficiency of vitamin C required by... 

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. 

The heart has a relatively low catalase activity, which, together with the superoxide dismutase (SOD) system, acts to remove hydrogen peroxide and superoxide radicals. In addition, in man, dietary vitamin C plays an important role in the reduction of vitamin E, an intrinsic antioxidant component of biological membranes (Chen and Thacker, 1986 Niki, 1987). Both vitamins C and E can also react directly with hydroxyl and superoxide radicals (HalliwcU and Gutteridge, 1989 Meister, 1992). 

Routine antioxidant vitamin supplementation, e.g. with vitamins C and/or E, of the diabetic diet should be considered. Vitamin C depletion is present in all diabetics irrespective of the presence of vascular disease. A recent study demonstrated no significant difference between the dietary intake of vitamin C (the main determinant of plasma ascorbate) in patients with diabetes and age-matched controls, confirming the view that ascorbate depletion is secondary to the diabetic process and su esting that diabetic patients require additional intakes of the vitamin to maintain optimal levels (Sinclair et /., 1994). Antioxidant supplementation may have additive beneficial effects on a wide variety of processes involved in diabetic vascular damage including blood pressure, immune function, inflammatory reactions. 

Sinclair, A.J. Taylor, P.B., Lunec, J., Girling, A.J. and Barnett, A.H. (1994). Low plasma ascorbate levels in patients with type 2 diabetes mellitus consuming adequate dietary vitamin C. Diabet. Med. 11, 893-898. 

The risk of colon cancer appears to be inversely related to calcium and folate intake. Calciums protective effect may be related to a reduction in mucosal cell proliferation rates or through its binding to bile salts in the intestine, whereas dietary folate helps in maintaining normal bowel mucosa. Additional micronutrient deficiencies have been demonstrated through several studies to increase colorectal cancer risk and include selenium, vitamin C, vitamin D, vitamin E, and 3-carotene however, the benefit of dietary supplementation does not appear to be substantial.11... 

ConsumerLab.com is an independent testing company that evaluates whether certain dietary supplements have met their standardization claims. Dietary supplements that have been tested include herbs (ginkgo, saw palmetto, ginseng), vitamins (vitamin C), and others (glucosamine, chondroitin, SAMe). Products that meet the German testing standards are published at the ConsumerLab.com website [33]. 

Reboul, E, Thap, S, Perrot, E, Amiot, MJ, Lairon, D, and Borel, P, 2007a. Effect of the main dietary antioxidants (carotenoids, gamma-tocopherol, polyphenols, and vitamin C) on alpha-tocopherol absorption. Eur J Clin Nutr 61, 1167-1173. 

Seddon, JM, Ajani, UA, Sperduto, RD, Hiller, R, Blair, N, Burton, TC, Farber, MD, Gragoudas, ES, Haller, J, Miller, DT, Yannuzzi, LA, and Willett, W, 1994. Dietary carotenoids, vitamin A, vitamin C, and vitamin E, and advanced age-related macular degeneration. J Am Med Assoc 272, 1413-1420. 

Reboul, E. et al. (2007b). Differential effect of dietary antioxidant classes (carotenoids, polyphenols, vitamins C and E) on lutein absorption. Br. J. Nutr. 97(3) 440-446. 

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