Food sources vitamin

The sulfonamides impede this synthesis and are therefore toxic to those bacteria that synthesize thek own foHc acid. Mammals cannot synthesize this and related vitamins and depend on food sources for them the sulfas are therefore not toxic to mammals in this regard. 

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]. 

Vitamin Bg is also found in a wide variety of food sources, It may be impossible to ask the patient to avoid these food sources entirely, but your patient may need to limit or decrease such intake to enhance or maintain the drug s effectiveness. Use the list below to teach your patient about possible food sources of vitamin Bg. 

TABLE 63-2. Food Sources of Iron, Folic Acid, or Vitamin B125... 

The need to include a variety of minerals in experimental diets has already been mentioned this was especially stressed (1920-1930) by Boyd-Orr, the director of the Rowett Institute for Animal Nutrition in Scotland. Increasingly refined food sources led to the identification of large numbers of trace elements (e.g., Cu, Mn, Mo, Zn) whose importance in the diet was suggested from hydroponic experiments with plant seedlings. Cobalt is an example of such a trace element. Vitamin Bj2 is synthesized by bacteria in the rumens of sheep and cattle but is absent from their fodder. In Australia, sheep feeding on cobalt-deficient pastures failed to thrive because vitamin B12 could no longer be made. 

Repeatedly it was shown that the semm retinol level and RBP level in prematures are significantly lower than that of neonates (Shah and Rajalekshmi, 1984). In the liver of prematures, significantly lower retinol levels can be foimd in comparison to neonates (Shensi et ah, 1985). Plasma values lower than 20 gg/dl are not rare in this case and they should be taken as an indicator of a relative vitamin A deficit. But a moderate vitamin A deficiency is not only a problem of countries with poor or inadequate food sources. 

Recently we published data that even in countries with excellent food sources and availability, insufficient vitamin A supply will occur (Schulz et ah, 2007). The aim of this trial was to analyze vitamin A and p-carotene status and investigate the contribution of nutrition to vitamin A and p-carotene supply in mother-infant pairs of multiparous births or births within short birth rates. Twenty-nine volimteers aged between 21 and 36 years were evaluated for 48 hours after delivery. In order to establish overall supply, retinol and p-carotene were determined in maternal plasma, cord blood, and colostrum via HPLC analysis. A food frequency protocol was obtained from all participants. Regardless of the high-to-moderate socioeconomic background, 27.6% of participants showed plasma retinol levels below 1.4 pmol/liter, which can be taken as borderline deficiency. In addition, 46.4% showed retinol intake <66% of RDA and 50.0% did not consume liver at all, although liver contributes as a main source for preformed retinol. Despite a high total carotenoid intake of 6.9 3.9mg/day, 20.7% of mothers showed plasma levels <0.5 pmol/liter p-carotene. 

Vitamin deficiency of Bj leads to the disease known as Beriberi. However, nowadays in the Western hemisphere, vitamin Bj deficiency is mainly found as a consequence of extreme alcoholism. In fact, the vitamin absorption by the gut is decreased and its excretion is increased by alcohol. Alcohol also inhibits the activation of vitamin Bj to its coenzyme form, thiamine pyrophosphate ester (TPP). There is no evidence of adverse effects of oral intake of thiamine [417]. The main food sources of vitamin Bj are lean pork, legumes, and cereal grains (germ fraction). It is soluble in water and stable at higher temperature and at pH lower than 5.0, but it is destroyed rapidly by boiling at pH 7.0 or above. 

Vitamin B12 consists of a porphyrin-like ring with a central cobalt atom attached to a nucleotide. Various organic groups may be covalently bound to the cobalt atom, forming different cobalamins. Deoxyadenosylcobalamin and methylcobalamin are the active forms of the vitamin in humans. Cyanocobalamin and hydroxocobalamin (both available for therapeutic use) and other cobalamins found in food sources are converted to the active forms. The ultimate source of vitamin Bi2 is from microbial synthesis the vitamin is not synthesized by animals or plants. The chief dietary source of vitamin Bi2 is microbially derived vitamin B12 in meat (especially liver), eggs, and dairy products. Vitamin Bi2 is sometimes called extrinsic factor to differentiate it from intrinsic factor, a protein normally secreted by the stomach that is required for gastrointestinal uptake of dietary vitamin B12. 

The RDAs for vitamin E are 10 mg and 8 mg a-TEday 1 for men and women, respectively. UK RNI values have not been established for vitamin E since its requirement is largely dependent on the content of polyunsaturated lipids in the diet. However, the Department of Health (1991) suggested that 4 and 3 mg a-TE day 1 are adequate for men and women, respectively. The major food sources of vitamin E are polyunsaturated vegetable oils and products derived therefrom (e.g. maragrine, salad dressings), green and leafy... 

Vitamin B12 deficiency normally results from indequate absorption rather than inadequate dietary intake. Pernicious anaemia is caused by vitamin B12 deficiency symptoms include anaemia, glossitis, fatigue and degeneration of the peripheral nervous system and hypersensitivity of the skin. The adult RDA and RNI for B12 are 2 and 1.5 figday- respectively. Unlike other vitamins, B12 is obtained exclusively from animal food sources, such as meat, fish, poultry, eggs, shellfish, milk, cheese and eggs. Vitamin B12 in these foods is protein-bound and released by the action of HC1 and pepsin in the stomach. 

Vitamin C Is the Synthetic Vitamin as Good as the Natural One A claim put forth by some purveyors of health foods is that vitamins obtained from natural sources are more healthful than those obtained by chemical synthesis. For example, pure L-ascorbic acid (vitamin C) extracted from rose hips is better than pure L-ascorbic acid manufactured in a chemical plant. Are the vitamins from the two sources different Can the body distinguish a vitamin s source ... 

Bi2 is unusual in several ways. The ability to form a metal-carbon bond in u biological system appears to be unique These are nature s only organometallic compounds. 9 Ii is the only vitamin known to contain a metal. It appears to be synthesized exclusively by bacteria. It is not found in higher plants, and although it is essential for all higher animals, it must he obtained from food sources, hence its designation as a vitamin ... 

Newstrom, H. Nutrients Catalog Vitamins, Minerals, Amino Acids, Macronutri-enis—Beneficial Use, Helpers, Inhibitors, Food Sources, Intake Recommendations, and Symptoms of over or under Use, McFarland Company, Inc., Publishers, Jefferson, NC, 1993. 

The liver of meat animals is a rich source of vitamin A, for this organ is the body s main storage site of the vitamin. Fish liver oils, particularly halibut liver oil, are incredibly rich in the vitamin and are too potent to be consumed as foods. Typical food sources of vitamin A (in /ag retinol equivalents/100 g) are sheep and ox liver, 15,000 butter, 830 cheese, 320 eggs, 140 herring and... 

It is fortuitous that indigenous concentrations of vitamin E in the principal food sources are on the order of mg rather than yug/100 g, for the tocopherols and tocotrienols exhibit relatively low intensities of UV absorption. Individual vitamers are characterized by a slightly different absorption maximum within the wavelength range of 292-298 nm in ethanol. Published A] m values for the tocopherols at their Amax in ethanol are a-T 70-73.7 at 292 nm, (3-T 86-87 at 297 nm, y-T 90-93 at 298 nm, and <5-T 91.2 at 298 nm (126). The different absorption characteristics among the vitamers necessitates the running of individual standards for accurate quantitation of each vitamer. The absorption intensity of a-tocopheryl acetate is lower still with an A j m value of only 40-44 at the Amax of 285.5 nm (44). Reported minimum detectable quantities of a-, / -, y-, and (5-tocopherols at 295 nm are, respectively, 50 ng, 70 ng, 90 ng, and 130 ng (127). 

For each vitamin, the food sources, biochemistry, metabolism, and biological functions, including both vitamin and nonvitamin activities, will be discussed briefly. References to recent review articles are included for the benefit of readers requiring more detailed information. 

Fruits and vegetables are the most common food sources for vitamin C (15-18). In food, vitamin C exists as two vitamers L-ascorbic acid (AA) and its oxidation product, dehydro-L-ascor-bic acid (DHAA) (Fig. 1) (15,17-19). Total Vitamin C is the sum of the AA and the DHAA contents. A stereoisomer, isoascorbic acid (IAA) is often added to food as an antioxidant. Both LAA and its oxidation product, dehydroisoascorbic acid (DHIAA), can interfere in Total Vitamin C determinations. 

Animal products are the principal food sources of vitamin B 2 (19,167). Organ meats, such as liver, kidney, brain, and heart, are the best sources. Plant products contain very little vitamin B,2, which is an important consideration for strict vegetarians. 

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