ascorbic-acid and Glycosuria

Topics: Adult; Aged; Ascorbic Acid; Bilirubin; False Negative Reactions; False Positive Reactions; Female; Glycosuria; Hemoglobinuria; Humans; Male; Middle Aged; Nitrites; Retrospective Studies; Urinalysis; Young Adult

Study was performed in order: (i) to assess the comparability of glucose, bilirubin, hemoglobin, leukocyte esterase, and protein; (ii) to assess accuracy of glucose, bilirubin, hemoglobin, leukocyte esterase, and protein; and (iii) to evaluate interference of ascorbic acid on the glucose, bilirubin, hemoglobin, and nitrite determination using 2 different dipsticks: iChem Velocity, Iris Diagnostics and Combur-10M, Roche Diagnostics.. Random urine specimens were included in the study. Comparability, accuracy, and ascorbic acid interference testing were performed.. Obtained results have shown almost perfect agreement for all parameters between 2 dipsticks in samples with negative ascorbic acid. Agreement in samples with positive ascorbic acid was not acceptable for bilirubin, protein, nitrite, and hemoglobin. Accuracy was not acceptable for hemoglobin and leukocyte esterase on both dipsticks. Ascorbic acid interference examination has shown that intensity of interference differs between dipsticks. Ascorbic acid interferes with glucose, hemoglobin, nitrite, and bilirubin at different concentrations causing false-negative results.. Obtained results indicate that it is necessary to determine diagnostic accuracy of used dipstick in order to define purpose of urinalysis. It is very important to choose dipstick with ascorbic acid indicator and to examine ascorbic acid impact on dipstick analytes independently of manufacturer claims.

Topics: Ascorbic Acid; Bilirubin; False Negative Reactions; Female; Glycosuria; Hemoglobins; Humans; Male; Urinalysis; Urine

Vitamin C may interfere with the results of urine dipstick tests. We investigated the incidence of urinary vitamin C and its interference with urine dipstick reagents using a vitamin C dipstick.. The incidence of urinary vitamin C was determined in patients and healthy individuals undergoing routine medical check-ups. Interference tests were performed using samples with various amounts of added vitamin C. For clinical samples, we identified false-negative dipstick glucose, hemoglobin, and leukocyte esterase results based on the urine sediment and serum glucose results.. Vitamin C was found in the urine of 18.1% of the subjects overall, and 23.1% of those undergoing medical check-ups. Dipstick results for glucose, leukocyte esterase, and hemoglobin differed between samples without vitamin C and with added vitamin C. When vitamin C was detected in clinical urine samples, 42.3%, 10.6%, and 8.2% of the glucose, hemoglobin, and leukocyte esterase dipstick tests were rated as false negative, respectively.. Vitamin C was frequently found in clinical urine samples, and its concentration was higher in individuals undergoing medical check-ups. Urinary vitamin C can interfere with the urine dipstick results. This study gives useful information for predicting false-negative rates of urine dipstick tests caused by vitamin C.

Topics: Ascorbic Acid; Carboxylic Ester Hydrolases; False Negative Reactions; Glycosuria; Hemoglobinuria; Humans; Reproducibility of Results; Urinalysis

New functionalized graphene oxide (FGO) was systematically coated on the fabricated Au-PCB for the detection of glucose in urine. The electrical response of FGO-Au-PCB exhibited a wide linearity of 1.7∼44.4 mM of glucose levels and a constant variables was less than 3% of the previously performed multiple measurements. The practical application has been demonstrated by measuring the electrical response against glucose in urine samples. In addition, our findings show similar improvement in urine glucose; within each current level, there were significant improvements in urine glucose. Comparison between the urine glucose and blood glucose showed no significant different level from the same subjects.

Topics: Ascorbic Acid; Biosensing Techniques; Blood Glucose; Electrochemistry; Electrodes; Glucose Oxidase; Glycosuria; Gold; Graphite; Humans; Oxides; Oxygen; Polymers; Urinalysis

Ascorbic acid at higher concentration in urine samples can lead to false negative results in a number of urine tests, with a potential risk of clinical findings being overlooked, particularly with glucose and hemoglobin. For this reason, the ascorbic acid status of urine samples should always be routinely known so as to establish what adjustment needs to be made. A much better approach, however, is to use a test which is by design largely resistant to ascorbic acid. We compared five very common 10-parameter urine test strips from different manufacturers. The results of this study show that of the strips tested, only the product Combur-Test from Roche Diagnostics is largely resistant to ascorbic acid interference. Even lowest - but clinically relevant - concentrations of erythrocytes (10/microL), hemoglobin (0.03 mg/dL), and glucose (50 mg/dL) were correctly detected with concentrations of up to 400 mg/L ascorbic acid. Higher analyte concentrations correctly reacted positive even in the presence of up to 1000 mg/L ascorbic acid.

Topics: Ascorbic Acid; Chemistry, Clinical; Drug Interactions; False Negative Reactions; Glycosuria; Humans; Indicators and Reagents

In Germany, urine analysis with dip sticks are used for screening of gestational diabetes. Our goal was to find the cut-off levels of glucose dip sticks and evaluate the influence of ascorbic acid on the result.. We took urine samples of 152 pregnant patients between 01/2004 and 10/2004. The glucose content of the urine was analyzed using several dip sticks (Combur10 Roche, Multistix 8SG Bayer, Diabur5000 Roche and by the hexokinase method. The ascorbic acid concentration of the specimen was determined.. Glycosuria test dip sticks have a good sensitivity and specificity of the expected positive/negative-reaction compared with the hexokinase method but showed a significant reduction of the color reaction at high concentrations of ascorbic acid.. High ascorbic acid concentrations cause a reduction in the color reaction of urine dip sticks. False-negative test stick measurements can appear in patients with low glycosuria. The rate of glycosuria shows high individual differences and dependent on the concentration of vitamin C. We conclude that dip sticks are not useful in prenatal management.

Topics: Adolescent; Adult; Ascorbic Acid; Diabetes, Gestational; False Negative Reactions; Female; Germany; Glucose; Glucose Tolerance Test; Glycosuria; Humans; Middle Aged; Pregnancy; Prenatal Care

The using of the low calorie soft drink "Forest gift" based on plant raw and enriched with vitamin C and iodine by patients with diabetes mellitus has resulted in the improvement of carbohydrates metabolism, provision of iodine and vitamin C and oxidant status of organism. Obtained data has promised to recommend this product for using in patient's ration.

Topics: Adult; Aged; Ascorbic Acid; Beverages; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Diet, Diabetic; Female; Food, Fortified; Glycated Hemoglobin; Glycosuria; Humans; Iodine; Male; Middle Aged; Time Factors

The nephrotoxicity of 4-amino-3-S-glutathionylphenol (PAP-GSH), a known metabolite of 4-amino-phenol (PAP), was determined in male Fischer 344 rats. Administration of a single dose of 40 or 60 mumol kg-1 caused a marked elevation in blood urea nitrogen and an increase in the urinary excretion of glucose, protein and gamma-glutamyltransferase (GGT). These changes were associated with histological alterations in the proximal tubule, where at the lower dose the lesion was restricted to the S3 region of the proximal tubule in the medullary rays, while at the higher dose the lesion extended to affect the S3 region in both the medullary rays and the outer stripe of the outer medulla. Studies with [35S]-PAP-GSH at 40 mumol kg-1 showed selective retention of radioactivity in the kidney, relative to other organs 24 h after dosing and that some radioactivity was covalently bound to renal proteins. Pretreatment of animals with probenecid, an inhibitor of renal organic anion transport, or aminooxyacetic acid, an inhibitor of cysteine conjugate beta-lyase, had little or no effect on the toxicity. In contrast, pretreatment of animals with acivicin, an inhibitor of gamma-glutamyltransferase, or co-administration of PAP-GSH with ascorbic acid almost completely protected against the nephrotoxicity. This protection was associated with a decreased concentration of radioactivity from [35S]-PAP-GSH in the kidneys and a decrease in the amount covalently bound to renal protein. Thus, the nephrotoxicity of PAP-GSH may be mediated by oxidation and further processing of the glutathione conjugate via gamma-glutamyltransferase.

Topics: Aminooxyacetic Acid; Animals; Ascorbic Acid; Blood Urea Nitrogen; gamma-Glutamyltransferase; Glutathione; Glycosuria; Ion Transport; Isoxazoles; Kidney; Lyases; Male; Oxidation-Reduction; Phenols; Probenecid; Proteinuria; Rats; Rats, Inbred F344; Sulfur Radioisotopes

A flow injection analysis (FIA) biosensor system has been developed for the determination of glucose from urine, blood plasma and foodstuffs. Glucose oxidase was immobilized onto porous aminopropyl glass beads via glutaraldehyde activation to form an enzyme column. The hydrogen peroxide released from the conversion of glucose to gluconic acid was monitored by a platinum electrode vs. silver/silver chloride poised at +700 mV. As a novel aspect to the improvement of the selectivity of the biosensor system, an anion exchange column was placed upstream to remove uric acid, ascorbic acid or acetaminophen, three major electroactive interfering substances which usually occur in urine and blood plasma. Among several resins tested, the effective adsorption of uric and ascorbic acids could be accomplished using an acetate anion exchanger, and the selectivity coefficient was pH dependent. The binding of acetaminophen to the resin was much less efficient and, in all cases, the selectivity coefficient was independent of the operating temperature up to 37 degrees C. When applied to real samples, the data obtained by the biosensor system compared well with those of the standard hexokinase assay. The immobilized glucose oxidase could be reused for at least 2000 repeated analyses without loss of its original activity.

Topics: Acetaminophen; Ascorbic Acid; Blood Glucose; Chromatography, Ion Exchange; Enzymes, Immobilized; Flow Injection Analysis; Food Analysis; Glucose; Glucose Oxidase; Glycosuria; Humans; Sensitivity and Specificity; Uric Acid

Topics: Adult; Ascorbic Acid; Blood Glucose; Glycosuria; Humans; Male

Marginally vitamin C-deficient guinea-pigs treated with the diabetogenic agent streptozotocin were compared with those liberally supplied with vitamin C, for functional indices of vitamin C status, particularly in the eye lens. Weanling male Dunkin-Hartley guinea-pigs were fed on diets with 0.1 g vitamin C/kg (marginally deficient), or 5 g/kg (liberally supplied), and some received intraperitoneal streptozotocin (two doses of 150 mg/kg body-weight). About half the streptozotocin-treated animals had high urinary glucose following an oral glucose dose; these animals also grew more slowly than the others. At 4 months after streptozotocin the animals were killed for measurement of tissue vitamin C, glucose and sorbitol. Streptozotocin moderately increased the concentration of glucose in plasma, lens and aqueous humour. Lens sorbitol levels increased only in the group exposed to streptozotocin plus marginal vitamin C. There was a significant (P less than 0.02) positive correlation between urinary glucose and lens sorbitol levels overall. Liberal vitamin C intake may thus counteract the effect of streptozotocin diabetes on lens sorbitol, suggesting a new function of vitamin C, possibly related to cataractogenesis and to the biochemical lesions associated with diabetes.

Topics: Adenosine Triphosphate; Animals; Aqueous Humor; Ascorbic Acid; Ascorbic Acid Deficiency; Blood Glucose; Body Weight; Diabetes Mellitus, Experimental; Diet; Glycosuria; Guinea Pigs; Lens, Crystalline; Liver; Male; Sorbitol; Streptozocin; Time Factors

Examination of 4379 routine urinalysis specimens with dipsticks sensitive to ascorbic acid showed that 22.8% were positive specimens. The mean urinary vitamin C concentration in this population was 2120 mumol/L. There was a high rate of false-negative dipstick results for hemoglobin in patients with vitamin C in the urine. The highest false-negative rates were observed in urine samples containing less than 50 erythrocytes per high-power field. In further experiments when volunteers consumed supplemental oral USP vitamin C at doses of 100, 250, 500, and 1000 mg or vitamin C-containing fruit juices, even the lowest doses of oral vitamin C or juice resulted in sufficient urinary vitamin C to produce false-negative dipstick results in hemoglobin and glucose testing. To prevent potentially dangerous false-negative results, screening urinalysis protocols relying only on dipstick testing should include a check for urinary vitamin C or use a dipstick that is not subject to vitamin C interference.

Topics: Ascorbic Acid; False Negative Reactions; Glycosuria; Hemoglobinuria; Humans; Reagent Strips; Urinalysis

Reflectometric measurement of urine test-strips, using the Urotron RL9, was employed to quantify urinary glucose and protein. Although the test-strips (Combur-9-Test) are designed for qualitative use, the reflectance intensities determined by the Urotron RL9 are applicable to quantitative analysis. Reflectance quantitation and conventional colorimetric methods were closely correlated for glucose (r = 0.953) and protein (r = 0.906). Intra-assay coefficients of variation of reflectance value were less than 5%. The negative influence of ascorbic acid on glucose determination was defined quantitatively. A significant positive interference from hemoglobin on protein determination was also demonstrated, but effectively eliminated after compensating for urine color.

Topics: Ascorbic Acid; Bilirubin; Calibration; Colorimetry; Glycosuria; Hemoglobins; Humans; Photometry; Proteinuria; Reproducibility of Results

Since evidence suggests that ascorbic acid deficits may provoke certain diabetic complications, it becomes necessary to develop a diabetic animal model which, like man, is unable to synthesize this vitamin. To this end, the present study monitored the diabetogenic effects of streptozotocin (STZ, 150 mg/kg) in the male guinea pig, a species rarely used in diabetes research. Over a 3-week period, body weight and relative food intake were lower in the STZ group compared to controls. The mean daily water intake and urine volume of the STZ group after 1 week were 175 and 270% of their initial pretreatment values, respectively, while control values were unchanged. The STZ group also exhibited a persistent glycosuria throughout the study. At the end of 3 weeks, aldehyde fuchsin staining of pancreatic beta cell granules (an index of stored insulin) was 58% lower in the STZ group compared to controls. Plasma C-peptide (indicator of insulin secretion) was expressed in human equivalents (mean +/- SEM). C-peptide was reduced in the STZ group (103 +/- 65 pg/ml) compared to controls (549 +/- 96 pg/ml); however, no change in plasma glucose was observed. Plasma ascorbic acid levels also were lower for STZ animals (150 +/- 26 micrograms%) versus controls (410 +/- 28 micrograms%). This study 1) demonstrates a diabetic syndrome in the STZ-treated guinea pig based on a reduced growth rate, beta cell dysfunction, polydipsia, polyuria and glycosuria, and 2) suggests the usefulness of this diabetic model in studies of pathologic mechanisms influenced by ascorbic acid.

Topics: Animals; Ascorbic Acid; Body Weight; Diabetes Mellitus, Experimental; Drinking Behavior; Eating; Glycosuria; Guinea Pigs; Islets of Langerhans; Male; Streptozocin; Water-Electrolyte Balance

Topics: Ascorbic Acid; False Positive Reactions; Glycosuria; Hemoglobinuria; Humans; Reagent Strips

Currently used test strip methods for the detection of glucose in urine are influenced by ascorbate and may thus give false negative results, e.g. in screening for diabetes. Six different test strips for urine glucose were evaluated for interference by ascorbate in vitro. Interference by ascorbate varied markedly, being highest at low glucose concentrations. Interference coefficients for the individual tests were calculated to serve as an approximate index of interference by ascorbate. A new test (BM 33.071, Boehringer Mannheim GmbH, currently used in Combur-9-Test/Chemstrip-9 and other multiple test strips of Boehringer Mannheim) was clearly much less influenced as no urine containing 5.5 mmol/l glucose was read as negative even at very high ascorbate concentration. Readability of test strips differed due to patchy colour reactions. Precision was good within-test strip and within-urine but markedly less between urines.

Topics: Ascorbic Acid; Drug Interactions; Evaluation Studies as Topic; False Negative Reactions; Glycosuria; Humans; Indicators and Reagents; Iodine; Reagent Strips

In order to assess different methods for early detection of unsuspected diabetes, urine and venous blood samples were collected at random from 1082 patients visiting a primary health care centre in southern Sweden. Blood glucose was analysed by the hexokinase method along with the Dextrostix-Eyetone reflectance meter. Urine glucose was determined by Clinistix, Diastix, Neostix, Rediatest, Clinitest and quantitatively by the hexokinase method. Patients fulfilling the criteria of a positive screen were subjected to a diagnostic investigation with an oral glucose tolerance test. Out of 89 positive screenees, 37 patients were classified as diabetics, showing a prevalence of diabetes in the study population of 3.4% according to the WHO criteria. Impaired glucose tolerance was found in 14 patients. In a control group of 56 patients, randomly selected among negative screenees, no cases of diabetes were found. Random blood glucose measurement by the hexokinase method, using 7 mmol/l as a screening level, had a significantly higher sensitivity (95%) than all urine glucose methods (59-30%) with comparable specificity (97-99%). Use of the Dextrostix-Eyetone reflectance meter resulted in a decrease in sensitivity to 75% without any change in specificity or predictability, compared with the hexokinase method. Urine testing for glucose was found to be a suboptimal method for early case finding of diabetes among patients receiving primary health care.

Topics: Adolescent; Adult; Aged; Ascorbic Acid; Blood Glucose; Child; Child, Preschool; Diabetes Mellitus; False Negative Reactions; Fasting; Female; Glucose Tolerance Test; Glycosuria; Humans; Infant; Infant, Newborn; Male; Middle Aged; Reagent Strips

Vitamin C (ascorbic acid), commonly taken as a dietary supplement and excreted in the urine, can interfere with peroxidase redox indicator systems such as those used in reagent-strip tests for urinary glucose and hemoglobin. We investigated whether the concentrations of ascorbic acid in urine after modest supplementary doses of vitamin C are high enough to interfere with such dipstick tests. After adding glucose or hemoglobin to urine collected from persons not taking vitamin C and from persons taking 350 to 1000 mg of vitamin C daily, we tested four reagent strips for interference and found that these commonly taken doses did frequently interfere with all test systems examined.

Topics: Ascorbic Acid; False Negative Reactions; False Positive Reactions; Glycosuria; Hemoglobinuria; Humans; Indicators and Reagents; Reagent Strips

Results for urinary glucose by the Boehringer Mannheim BM33071 test pad and a hexokinase-based method agree well. The new test, which involves the glucose oxidase/peroxidase reaction, measures as little as 260 mg of glucose per liter. Acetoacetate, beta-hydroxybutyrate, and human hemoglobin do not interfere.

Topics: 3-Hydroxybutyric Acid; Acetoacetates; Ascorbic Acid; Evaluation Studies as Topic; Glucosephosphate Dehydrogenase; Glycosuria; Hemoglobinuria; Hexokinase; Humans; Hydroxybutyrates; Indicators and Reagents; Reagent Strips

Topics: Ascorbic Acid; Glycosuria; Humans; Indicators and Reagents; Urine

We report a girl aged 31/2 years in whom signs and symptoms of diabetes mellitus were falsified by the mother. Evaluation in hospital rapidly ruled out diabetes mellitus and the use of ascorbic acid as a marker enabled us to prove urine substitution by the girl's mother.

Topics: Ascorbic Acid; Child, Preschool; Diabetes Mellitus; Female; Glycosuria; Humans; Mother-Child Relations; Munchausen Syndrome

The influence of ascorbic acid on commercial rapid diagnostic tests for glucosuria is demonstrated in vitro. Although much work has been done to stabilize the tests against such interference, and although manufacturers of tests trips declare their products now to be fairly stable against ascorbic acid 'at higher glucose levels', all the investigated commercial rapid diagnostic tests for glucose at the lower pathological range of glucosuria were substantially influenced by ascorbic acid at potentially physiological concentrations.

Topics: Ascorbic Acid; Glycosuria; Humans; Indicators and Reagents; Reagent Strips

Diabur-test 5000, a new test strip for estimation of urinary glucose, was compared with the hexokinase glucose-6-phosphate dehydrogenase method in more than 2500 urine samples. By combination of two test ranges glucose concentrations of up to 5% can be detected by the strip test. After a reading time of 2 minutes, very precise estimation of urinary glucose is possible in eight steps from negative to 5%. False estimations of more than one color step virtually do not occur. Ketone bodies, salicylic acid and several antibiotics do not influence the test strip. Ascorbic acid shows a slight influence only in concentrations above 40 mg/dl. This influence disappears with glucose concentrations of more than 0.5%. Good correlation with the reference method, wide range of readings and simple handling make the test strip suited for the laboratory and particularly for self control of diabetic patients.

Topics: Anti-Bacterial Agents; Ascorbic Acid; Diabetes Mellitus; Glycosuria; Humans; Indicators and Reagents; Ketone Bodies; Reagent Strips; Salicylates

Inhibition of a variety of commercial test strips for hyperglucosuria was experienced in laboratory mice. All mouse strains tested were found to have sufficiently high levels of ascorbic acid to cause inhibition, and male levels were higher than those of females. A regime to obtain optimum detection of positive results is discussed.

Topics: 2,6-Dichloroindophenol; Animals; Ascorbic Acid; False Negative Reactions; Glucose Oxidase; Glycosuria; Mice; Mice, Inbred C3H; Mice, Inbred C57BL; Mice, Inbred Strains; Reagent Strips; Rodent Diseases

Topics: Ascorbic Acid; Drug Interactions; Erythrocytes; Glycosuria; Humans; Indicators and Reagents; Reagent Strips; Urine

Ascorbic acid and hippuric acid (from cranberry juice) are commonly used to acidify the urine for the purpose of enhancing the degradation of therapeutic methenamine mandelate to urinary formaldehyde. A study was made of 27 nondiabetic geriatric patients with indwelling Foley catheters and chronic bacteriuria who were treated with methenamine mandelate (4 gm), ascorbic acid (4 gm), and cranberry cocktail (1 liter) daily. All of 972 urine samples showed formaldehyde in mean concentrations between 14 and 25 microgram/ml. No glucose was found when the urine was tested by the copper-reduction method. In vitro false positive reactions reported in the literature do not appear to be duplicated as an in vivo problem.

Topics: Aged; Ascorbic Acid; Bacteriuria; Copper; False Positive Reactions; Female; Formaldehyde; Glucose Tolerance Test; Glycosuria; Hippurates; Humans; Male; Methenamine

Topics: Albuminuria; Ascorbic Acid; Bacteriuria; Glycosuria; Hematuria; Humans; Indicators and Reagents; Methods; Reagent Strips; Urine

Topics: Ascorbic Acid; Blood Glucose; Glycosuria; Humans; Reagent Strips

A new testing set for diluting urine allows to determine glucose in urine with the Diabur-test strip up to a concentration of 8.0 g/dl. The dilution by means of a pipette is absolutel;y practicable at a distinguished precision; the results show an excellent correlatiopn with the quantitative hexokinase method. Of all possible interfering substances tested only ascorbic acid influenced the reaction which, however, interfered only when minor glucosuria was present.

Topics: Ascorbic Acid; Diabetes Mellitus; Glycosuria; Humans; Reagent Kits, Diagnostic

Topics: Ascorbic Acid; Glucose Oxidase; Glycosuria; Humans; Indicators and Reagents; Methods; Reagent Strips

Topics: Ascorbic Acid; False Negative Reactions; False Positive Reactions; Glycosuria; Humans; Methods

Topics: Ascorbic Acid; False Negative Reactions; Glycosuria; Humans

Topics: Ascorbic Acid; False Positive Reactions; Glycosuria; Humans

Topics: Ascorbic Acid; Glycosuria; Humans; Indicators and Reagents; Reagent Strips

A study was conducted to determine if high doses of ascorbic acid would affect the two-drop Clinitest determination for glucosuria in normal individuals. Numerous secondary literature sources indicate that large doses of ascorbic acid may cause a false positive Clinitest result. Three-gram and nine-gram doses of ascorbic acid following two dosing schedules (once daily and three times daily) were taken by nine normal individuals to determine if the renal excretion of large enough quantities of ascorbic acid or its metabolites would produce false positive results with the two-drop Clinitest procedure. Each dose was given for seven days in each schedule. There were only two (0.27%) trace positive Clinitest determinations reported out of 748 Clinitest determinations. High doses of ascorbic acid in normal individuals do not appear to affect the two-drop Clinitest determination for urinary glucose. The study indicates a need to be cautious about secondary literature references on drug-laboratory test interferences.

Topics: Ascorbic Acid; Copper; Diabetes Mellitus; False Positive Reactions; Glycosuria; Humans; Reagent Kits, Diagnostic; Sulfates

The recent popularization of self-prescribed large doses of vitamin C has increased the possibility for erroneous conclusions to be drawn from standard clinical methods used in urinary glucose monitoring, due to interference with these methods by the greatly elevated excretion of vitamin C. The coupled-enzyme-chromogen strip tests showed erroneously negative glucose levels in urines of both a diabetic individual and a subject with a genetic low renal threshold for glucose when they were supplementing their normal diets with 1-2 g vitamin C per day. With this regimen, their urinary vitamin C levels reached 200 mg/dl (11.4 mmol/l). For normal urine with vitamin C added, false-positive tests for glucose were found using Benedict's reagent when vitamin C was present at 250 mg/dl (14.3 mmol/l) or higher concentrations. In diabetic individuals consuming large quantities of vitamin C, this interference with standard coupled-enzyme-chromogen strip tests or Benedict's test could present a significant problem in diagnosis and clinical management of the disease. A simple anion exchange method of treating the urine was used to correct the false results.

Topics: Adult; Ascorbic Acid; Diabetes Mellitus; False Negative Reactions; False Positive Reactions; Glycosuria; Humans; Male; Urine

Topics: Acidosis; Ascorbic Acid; Blood; Cholesterol; Gastrointestinal Diseases; Glycosuria; Humans; Hydrogen-Ion Concentration; Hyperglycemia; Kidney Calculi; Oxalates; Prothrombin; Vitamin B 12

Topics: Adolescent; Adult; Age Factors; Ascorbic Acid; Carbohydrates; Child; Child, Preschool; Creatinine; Glycosaminoglycans; Glycosuria; Hexosamines; Humans; Hydrogen-Ion Concentration; Infant; Sulfates; Urine

Topics: Ascorbic Acid; Chromatography, Ion Exchange; Evaluation Studies as Topic; Glycosuria; Humans; Methods

Topics: Ascorbic Acid; Evaluation Studies as Topic; False Negative Reactions; Glucose Oxidase; Glycosuria; Humans; Indicators and Reagents; Reagent Strips; Tablets

Topics: Ascorbic Acid; False Negative Reactions; Female; Glycosuria; Humans; Methods; Pregnancy

Topics: Ascorbic Acid; Carcinoid Tumor; Chromatography, Thin Layer; Clinical Enzyme Tests; Diabetes Mellitus; Diagnostic Errors; Diuresis; False Negative Reactions; False Positive Reactions; Gentisates; Glycosuria; Humans; Methods; Osmolar Concentration; Reagent Strips

Topics: Adult; Ascorbic Acid; Bilirubin; Blood Glucose; Erythrocytes; Female; Fluorides; Glucose; Glucose Oxidase; Glycosuria; Hematocrit; Hemolysis; Humans; Methods; Middle Aged; Peroxidases; Sodium; Time Factors; Uric Acid

Topics: Acetates; Ascorbic Acid; Autoanalysis; Bilirubin; Blood Glucose; Carbohydrates; Creatinine; Ethylenes; Glycols; Glycosuria; Hexokinase; Indicators and Reagents; Methods; Spectrophotometry; Toluidines

Topics: Ascorbic Acid; Autoanalysis; Glycosuria; Ion Exchange Resins; Methods

Topics: Ascorbic Acid; Chlorpromazine; Clinical Laboratory Techniques; Drug Interactions; Glycosuria; Humans; Kidney Function Tests; Pregnancy Tests

Topics: Ascorbic Acid; Glucose Oxidase; Glycosuria; Humans

Topics: Ascorbic Acid; Atrophy; Body Temperature Regulation; Burns; Fractures, Bone; Glycosuria; Humans; Hyperglycemia; Muscle Proteins; Nutritional Physiological Phenomena; Proteins; Wounds and Injuries

Topics: Animals; Ascorbic Acid; Chickens; Diabetes Mellitus; False Positive Reactions; Female; Fetal Death; Fetus; Glycosuria; Guinea Pigs; Humans; Oxalates; Phosphates; Pregnancy; Rats; Urinary Calculi

Topics: Age Factors; Alveolar Process; Ascorbic Acid; Avitaminosis; Blood Proteins; Bone Resorption; Glycosuria; Humans; Hyperglycemia; Hypoglycemia; Oral Health; Toothbrushing

Topics: Ascorbic Acid; False Negative Reactions; Glucose Oxidase; Glycosuria; Humans; Injections, Intravenous; Tetracycline

Topics: Ascorbic Acid; Female; Glucose Oxidase; Glucose Tolerance Test; Glycosuria; Humans; Indicators and Reagents; Male; Methods; Oxygen Consumption; Polarography

Topics: Alkaptonuria; Ascorbic Acid; Bilirubin; Biphenyl Compounds; Clinical Laboratory Techniques; Cyanates; Enzymes; Epinephrine; Fructose; Glucose Oxidase; Glucose Tolerance Test; Glycosuria; Humans; Hydrazones; Hydroquinones; Indicators and Reagents; Iron; Jaundice; Melanins; Metabolic Diseases; Peroxidases; Phenylacetates; Silver Nitrate

Topics: Ascorbic Acid; Female; Glucose Oxidase; Glucosephosphate Dehydrogenase; Glycosuria; Hexokinase; Humans; Male

Topics: Adrenal Glands; Adrenocorticotropic Hormone; Animals; Ascorbic Acid; Diabetes Mellitus, Experimental; Glycosuria; Histamine; Hypophysectomy; Insulin; Male; Pituitary Gland; Pituitary-Adrenal System; Rats; Stress, Physiological

Topics: Alcohol Oxidoreductases; Ascorbic Acid; Chemistry, Clinical; Creatine; Galactose; Glucose Oxidase; Glycosuria; Humans; Ion Exchange Resins; Sodium Chloride; Urea; Uric Acid

Topics: Ascorbic Acid; Female; Glucosephosphate Dehydrogenase; Glycosuria; Hexokinase; Humans; Methods; Spectrophotometry

Topics: Animals; Ascorbic Acid; Glycosuria; Humans

Topics: Ascorbic Acid; Female; Glycosuria; Humans; Male

Topics: Ascorbic Acid; Automation; Body Fluids; Clinical Laboratory Techniques; Glucose; Glucose Oxidase; Glycosuria; Humans; Peroxidases; Uric Acid

Topics: Ascorbic Acid; False Negative Reactions; Glucose Oxidase; Glycosuria; Humans; Oxidoreductases

Topics: Ascorbic Acid; Blood Chemical Analysis; Glycosuria; Humans; Leukocytes; Metabolism; Vitamins

Topics: Alkalies; Arabinose; Ascorbic Acid; Chemistry Techniques, Analytical; Diagnostic Tests, Routine; Fructokinases; Fructose; Fructose Metabolism, Inborn Errors; Galactose; Gluconates; Glucuronates; Glycosuria; Hydroxides; Lactates; Lactose; Maltose; Mannose; Potassium; Research; Ribose; Sorbose; Sucrose; Urine; Xylose

Topics: Ascorbic Acid; Glycosuria; Humans

Topics: Ascorbic Acid; Glycosuria; Vitamins

Topics: Ascorbic Acid; Biomedical Research; Glucose; Glycosuria; Humans

Topics: Ascorbic Acid; Glucose; Glucose Oxidase; Glycosuria; Hematologic Tests; Humans; Oxidoreductases; Vitamins

Topics: Ascorbic Acid; Glucose; Glycosuria; Humans; Vitamins

Topics: Ascorbic Acid; Cell Differentiation; Glycosuria