Vitamin clinical significance

Jeffrey, G.P., Muller, D.P.R., Burroughs, A.K., Matthews, S., Kemp, C., Epstein, O., Metcalfe, T.A., Southam, E., Tazir-Melbourcy, M., Thomas, P.K. and McIntyre, N. (1987). Vitamin E deficiency and its clinical significance in adults with primary biliary cirrhosis and other forms of chronic liver disease. J. Hepatol. 4, 307-317. 

The consequence of bacterial bile acid metabolism [66, 74,77] is hardly clinically significant malabsorption [6] in otherwise healthy individuals [32,79], but in predisposed individuals this may be different. Accordingly, omeprazole interferes with the absorption of vitamin B12 [80-83] and protein assimilation [84], The mechanism for altered vitamin B12 absorption is prevention of its cleavage from dietary protein [83], for which the importance of the concurrent bacterial overgrowth has not yet been ruled out. 

Because of the clinical significance of vitamin C, it is essential to In-able to detect and quantify its presence in various biological materials. Ana lytical methods have been developed to determine the amount of ascorbic acid in foods and in biological fluids such as blood and urine. Ascorbic acid may be assayed by titration with iodine, reaction with 2,4-dinitrophenylhy-drazine, or titration with a redox indicator, 2,6-dichlorophenolindophenol (DCIP) in acid solution. The latter method will be used in this experiment because it is reasonably accurate, rapid, and convenient and can be applied to many different types of samples. 

In a 56-week study there was an association between the use of acarbose and low vitamin B6 concentrations, which occurred in 33% of 240 patients taking acarbose compared with 23% of 119 patients taking placebo (38). Calcium concentrations fell more often in those who took acarbose (28% versus 16%) but returned to normal by the end. These findings have not been reported elsewhere and do not appear to be clinically significant. 

Vitamin D-binding protein and its associated vitamin are lost in nephrotic urine. Biochemical abnormalities in nephrotic patients (children and adults) include hypocalcemia, both total (protein-bound) and ionized hypocalciuria, reduced intestinal calcium absorption and negative calcium balance reduced plasma 25-hydroxycholecalciferol and 24,25-dihydroxycholecalciferol and, surprisingly, also 1,25-dihydroxycholecalciferol and blunted response to parathormon (PTH) administration and increased PTH levels. Clinically, both osteomalacia and hyperparathyroidism have been described in nephrotic patients, more commonly in children than in adults, but bone biopsies are commonly normal, and clinically significant bone disease is very rare in nephrotic subjects. There is, however, evidence that patients with renal failure accompanied by nephrotic range proteinuria may be particularly prone to develop renal osteodystrophy. 

The clinical significance of these new fractions and their physiological fluctuations and relation to disease is not yet clear. But these new techniques give a hopeful renewal to electrophoretic work. Ultimately some components of serum, difficult to determine with the usual methods, such as some organic anions, enzymes, vitamins, and hormones might be visualized, separated, and collected. 

Vitamin B12 depletion could be expected in chronic alcoholics since their diet is often low in animal protein, and, although many alcoholic beverages are the result of bacterial fermentation, they have nevertheless been found to be essentially free of vitamin B12 (L9). Reduced levels of serum vitamin B12 have been reported in alcoholics by some workers (H16.L9) while others have found the concentration to be normal or elevated (Dll). Because of the liver damage often associated with alcoholism, serum levels of the vitamin may be normal or elevated even though liver stores of the vitamin are reduced (RIO, S15). An elevated level of serum vitamin B12 binding protein may also serve to increase the vitamin B12 level. The interpretation of serum vitamin B12 levels in alcoholics is of very limited importance since a clinically significant deficiency of the vitamin very rarely occurs. 

ALCOHOL VITAMIN C (large doses, e.g. 1000 mg) May t elimination of alcohol, but this is unproven Uncertain Unlikely to be of clinical significance... 

There are some vitamins, which are adversely effected by exposure to UV-VIS radiation during administration if not photoprotected. Among the fat-soluble vitamins, vitamin A (retinol, retinyl palmitate) photodegradation is of clinical significance. 

How is Vitamin D deficiency manifested Or Clinical Significance of Vitamin D Deficiency. 

There are only two clinically significant reactions in the body that require vitamin B12 as a cofactor. 

Liquid paraffin impairs the absorption of fat-soluble vitamins (A, D, E, and K). This has rarely been reported to be of clinical significance, although one case of rickets has been reported (14). 

Determination of vitamin D is useful in the differential diagnosis of hypocalcemia, hypercalcemia, or hypercalciuria and for evaluating vitamin D status in health and in bone and mineral disorders (see Calcium, Clinical Significance, Hypocalcemia, and Hypercalcemia and Metabolic Bone Diseases). Only the measurements of 25(OH)D and 1,25(0H)2D have proven clinical value. Routine cfinical determination of vitamin D, 24,25(0H)2D, or other metabolites is not indicated at this time. 

Little information is available concerning alterations in vitamin requirements in ARF. Reduced plasma concentrations of vitamin A, ascorbate, vitamin D, and vitamin E have been reported in patients with ARF, whereas vitamin K concentrations are relatively increased. Losses of vitamins via dialysis also must be considered. Traditional HD clears several water-soluble vitamins such as folic acid, vitamins C and B12, and pyridoxine, but not the highly protein-bound vitamins A and D. The clinical significance of these findings in ARF is unknown. Currently, it seems prudent to administer vitamins at least daily in doses recommended by the Nutrition Advisory Group of the American Medical Association for patients receiving PN (see Chap. 137)." Administration of ascorbic acid should be restricted to under 200 mg/day to avoid secondary oxalosis which may worsen renal function." If the enteral route is used for nutritional support, vitamin administration should at least meet the recommended daily allowances (RDAs). 

There are anecdotal reports of a 25% decrease in serum levels of fluphenazine when vitamin C was added to the regimen (probably not of clinical significance). ... 

The authors of this report suggest that what happened was possibly due to the presence of vitamin E in the Curbicin preparation (each tablet contains 10 mg), but vitamin E , (p.401) does not normally affect INRs. The clinical significance of this interaction is unknown, but bear it in mind in the case of an unexpected response to treatment. 

Vitamin C reduces the bioavailability of propranolol but the extent is too small to be of clinical significance. 

The clinical significance of these studies is unclear as there appear to be no published case reports of any adverse effects due to this interaction. However, in some patients, changes in ciclosporin levels may significantly affect ciclosporin immunosuppression, and dose modification may be required. Patients should be questioned about their intake of vitamin sup-... 

As mentioned, some patients have documented deficiencies of several vitamins. Indeed, isolated clinically significant deficiency of a single vitamin is probably rare. Yet the import of multiple deficiencies is not always clear. Even for the best recognized avitaminoses, such as pellagra or the Wernicke-Korsakoff syndrome, defects in cognition are attributable to lack of more than just the one classically implicated vitamin. Deficiency of multiple water soluble vitamins pertains especially to alcoholics, to the elderly, and to severely ill hospitalized patients. For example, low folate stores, combined with inadequate niacin and thiamine, probably contribute to the chronic memory disorder of alcoholism. 

As the kidney has a major role in B vitamin metabolism, it is plausible that chronic kidney disease may affect vitamin status to a clinically significant extent. This holds especially true in end-stage renal disease, when the dialysis process may cause additionally vitamin losses (Heinz et al. 2008). Although vitamin supplementation among patients with end-stage renal disease is widely practised, the scientific evidence for doing so was, until recently, very vague. And contrary to common beliefs, supplementation with B vitamins in patients... 

A number of studies have examined RBP levels (and usually TTR and vitamin A levels as well) in patients with various kinds of acute and chronic diseases of the liver (Smith and Goodman, 1971 Kindler, 1972 Prellwitz et al., 1974 Skredeeta/., 1975 Brissot er a/., 1978 Vahlquist a/., 1978a Russell et a/., 1978 McClain et al., 1979). In patients with clinically significant hepatic parenchymal disease, the plasma levels of vitamin A, RBP, and TTR have usually been found to be substantially depressed. The low levels of RBP and TTR presumably reflect a reduced rate of production of the proteins by the diseased liver. 

The blocking or incomplete antibodies produced in man as a result of the antigenic activity of the Rh factors are also of considerable clinical significance. It, therefore, became of interest to determine whether such incomplete antibodies could be produced in the rat and, if so, in what manner their production might be influenced by vitamin intake (Axelrod and Pruzansky, 1954). In all of our previous work only the complete hemagglutinating antibodies were determined. It is conceivable that those vitamin-deficient animals which failed to produce the complete antibodies might still possess the ability to fabricate the... 

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]. 

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