Urinary Excretion Of Thiamine Research Articles

Influence of the rat diet enrichment with oat β-gucans on the assimilation of B group vitamins, mineral elements and lipid metabolism

Despite the widespread use of oat β-glucans as ingredient of foods and dietary supplements, there is insufficient data on their effect on the metabolism of vitamins and minerals. The purpose of the study was to evaluate the effect of including oat bran with a high content of β-glucans (β-glucan) in the diet on the absorption of micronutrients and lipid metabolism in growing rats deficient in vitamins D, group B and trace elements (iron, copper, zinc). Material and methods. After the development of micronutrient deficiency (for 23 days), in order to assess the effect of oat bran (5%) with a high content of β-glucans on the correction of the micronutrient status of growing male Wistar rats (with initial body weight of 70.7±0.7 g), the missing micronutrients were introduced in the semi-synthetic diet deficient in vitamins D, group B, iron, copper and zinc within 7 days either along with β-glucan (1.47%) or without its addition. Indicators of micronutrient sufficiency (riboflavin serum concentration, daily urinary excretion of thiamine, riboflavin and 4-pyridoxic acid, measured by fluorometric methods; serum concentration and urinary excretion of calcium, magnesium, iron, zinc, copper, phosphorus, measured by the atomic absorption method or using standard methods on a biochemical analyzer) and the biochemical parameters of blood serum were compared with the parameters of rats adequately provided with all micronutrients throughout the experiment. Results. Replenishment of missing micronutrients in the diet of rats with deficiency in vitamins D and group B, iron, copper and zinc for 7 days led to the elimination of deficiency of vitamins B1, B2 and B6, regardless of the presence of β-glucans in the diet. At the same time, against the background of the presence of β-glucans in the feed, an increase in the absorption of iron was observed, as evidenced by an increase by 1.73 times in iron blood plasma level (р<0.05) and a tendency towards its urinary excretion decrease by 1.60 fold (р<0.10) compared to animals from the control group. Adding oat bran with β-glucans to the feed did not lead to a decrease in blood plasma level of total cholesterol and low-density lipoproteins cholesterol. The levels of high-density lipoprotein cholesterol and triglycerides in rats of all three groups did not have statistically significant differences. Conclusion. The presence of β-glucans in the diet had virtually no effect on the absorption of B vitamins and improved the absorption of iron.

Thiamine (Vitamin B1) Is Often Misunderstood to Be Consumed by Excessive Carbohydrate Intake

ObjectivesThiamine acts as a coenzyme (prosthetic group) after converting to thiamine pyrophosphate in crucial metabolic enzymes of pyruvate dehydrogenase, α-ketoglutarate dehydrogenase and transketolase. Theoretically, thiamine should not be consumed by an increase in the number of substrates for those enzymes. However, thiamine is often described to be consumed by excessive carbohydrate intake. Such a possible misunderstanding is assessed in the relevant literature. MethodsThe original paper (Elmadfa, et al. Int J Vitam Nutr Res 2001), which seems to mislead the reader into considering an increase in thiamine requirement for excessive carbohydrate intake, and the relevant papers were reviewed. ResultsThe original paper demonstrated that increases in carbohydrate intake from 55% to 65% and 75% of total energy caused decreases in plasma and urine concentrations of thiamine, while erythrocyte transketolase activity remained unchanged. This seems to misleadingly support the idea that excessive carbohydrate intake increases the thiamine requirement for carbohydrate metabolism. It could be interpreted as the decreases of thiamine concentrations were observed only during an adaptation period. It was reported that diabetic patients had low plasma thiamine levels in association with increased renal clearance and fractional excretion of thiamine, without a decrease in erythrocyte transketolase activity (Thornalley, et al. Diabetologia 2007). As a similar case of possible misinterpretation, a case report (Watson, et al. Ir J Med Sci 1981) demonstrated that glucose loading precipitated thiamine deficiency in malnourished patients with latent thiamine deficiency. ConclusionsFrom the relevant literature, it is inferred that excessive carbohydrate intake in people without hyperglycemia could lead to a small increase, if any, in urinary thiamine excretion, but not to an increase in thiamine requirement for glucose metabolism. Even in the academic field, it seems that thiamine is often misunderstood to be consumed by excessive carbohydrate intake. Funding SourcesNone.

Prevalent Low Thiamine Status Among Adults Living in Seoul Metropolitan Area (South Korea).

The thiamine status of South Korean people has not been recently reported. Therefore, the aim of this study was to determine thiamine intake and status of Korean adults based on a biochemical index. Three consecutive 24-h food recalls and morning first-urine samples were obtained from 143 healthy adults (65 men and 78 women), aged 20-64years, living in Seoul metropolitan area, Korea. Daily dietary thiamine intake of men and women was 1.42±0.37mg and 1.18±0.24mg, respectively. Only 9.1% of the subjects consumed less total thiamine (dietary plus supplemental thiamine) than the estimated average requirement for Koreans. The top 10 major dietary thiamine sources were pork, polished rice, ramyeon (Korean instant noodles), baechukimchi (Chinese cabbage), mandarin oranges, chicken, cow's milk, bread, beef, and potatoes. Those top 10 foods provided 57.85% of the subjects' dietary thiamine intake and the top 30 food sources provided 77.23% of their dietary thiamine intake. Urinary thiamine excretions for men and women were 37.20±26.54 and 39.09±28.80μg/g creatinine, respectively. Urinary thiamine excretion was positively correlated with total thiamine intake (r=0.3349, p<0.0001). Approximately 40% of the subjects had urinary thiamine excretion<27μg/g creatinine, indicating thiamine deficiency. In conclusion, thiamine intake among Korean adults in this study was generally adequate, but there was a high prevalence of a low thiamine status. Further study is required to explain the incongruity of adequate intake and low thiamine status thiamine in the South Korean population.

Influence of Glucose Dosage in Parenteral Nutrition on Body Thiamine Levels in Rats.

The objective of this study was to determine the relationship between glucose dosage in parenteral nutrition and reductions in levels of body thiamine in rats. Vitamin-free infusions with differing amounts of glucose were administered to normal or thiamine-deficient rats for 5 days, after which urinary thiamine excretion and the amounts of thiamine in the blood, liver, brain, and skeletal muscles were measured. The total energy dosage was set at three levels (98, 140, and 196 kcal/kg), and the dose of amino acids was constant among all groups. Urinary thiamine excretions on Day 5 decreased with increasing glucose dosage in the infusions. In normal rats, the amount of thiamine in the blood and all organs decreased compared with the diet group; however, no significant differences were found among the infusion groups. In thiamine-deficient rats, on the other hand, the amount of thiamine in the liver and skeletal muscles did not differ significantly among infusion groups; however, the amount of thiamine in the brain and blood decreased with increasing glucose dosage. An organ-specific correlation was found between glucose dosage in infusions and reductions in levels of thiamine. To prevent thiamine deficiencies from affecting the central nervous system, greater caution must be exercised during high-caloric parenteral nutrition. However, a constant supply of thiamine seemed to be essential, irrespective of the amount of energy supplied via parenteral nutrition, to maintain a sufficient level of thiamine in the body.

Effect of B-vitamin deficiency on biochemical, immunologic markers and trace element status of rats and mice of various lines

Biochemical, vitamin, trace element and immunological changes were searched for the combined nutritional deficiency of vitamins B1, B2, B6 on in vivo models in rats and mice. Female rats of Wistar (W) strain and hybrids of the 1st generation of Dark Aguti and Wistar (DA x W) strains, female mice of BALB/c strain and DBCB tetrahybrids were used in experiment. Animals received for 35 days a balanced diet (control) according to AIN-93 or a similar diet with the exception of vitamins B1, B2, B6 (experimental groups). The content of vitamins B1, B2 in liver, riboflavin blood plasma level and urinary excretion of thiamine, riboflavin and 4-pyridoxic acid were determined, as well as in rats: blood and liver content of α-tocopherol and retinol, blood biochemical indices of lipid and nitrogen metabolism, activity of cytochrome P isoforms-450 (CYP) in liver; in mice: the circulating levels of pro- and anti-inflammatory cytokines of blood plasma, in animals of both species - the content of essential and toxic elements in the kidneys. DAxW rats compared to W and DBCB mice compared to BALB/c were more sensitive to the development of B-vitamin deficiency judging by the B-vitamin status indicators. In the rats of the experimental groups, there were signs of a deterioration in blood and liver levels of vitamin E, multidirectional shifts in vitamin A sufficiency, increased activity of the CYP3A isoform (6β-TG), a decrease in triglycerides, total protein and albumin fraction levels with an increase in urea level. Manifestation degree of these effects depended on the choice of the animal's line. In mice, the B-vitamin deficiency was characterized by an increase in the levels of proinflammatory cytokines TNF-α, IL-10, IL-Ιβ, IL-6 and a decrease in IFN-γ and IL-17A. The content of magnesium, copper, zinc, chromium and silver was lowered, of cesium - was increased in the kidneys of the rats of the experimental groups. In mice, B-vitamin deficiency resulted in diminishment of magnesium, copper, zinc, chromium, selenium, cadmium and lead content, excess accumulation of cobalt and cesium. Some of these biomarkers are supposed to be used in pre-clinical evaluation of the effectiveness of new vitamin complexes, specialized foods and dietary supplements, as well as studies of interactions of various vitamins.

Assessment of vitamin supply in preschoolers

Objective : to assess the vitamin status of preschoolers according to the results of one-hour urinary vitamin excretion and the data of actual nutrition. Subjects and methods . A survey was conducted in winter 2016, covering 33 children (19 boys and 14 girls) aged from 2 to 7 years who went to a Yekaterinburg preschool educational institution. The amount of essential nutrients was calculated according to the data of actual nutrition during 5 days. The vitamin status was evaluated from the urinary excretion of thiamine, riboflavin, and 4-piridoxyl acid, by testing a morning fasting urine portion. Results. Determination of urinary excretion revealed deficiency of vitamin B2 in 24.2% of the examinees, and that of vitamins B1 and B6 in significantly more children (in 66.7–69.7%). According to the actual nutrition data, inadequate intakes of vitamins B2, A, and C were detected in 27.3–30.3% of the examinees, those of niacin and vitamin B1 in 54.5 and 69.7%, respectively. The proportion of the coincidental data obtained by two methods for assessing the vitamin status was 63.6% for vitamin B1 and 69.7% for vitamin B2. Conclusion . The findings suggest that the two methods to assess the supply of vitamins B1 and B2 are interchangeable and the children need additional vitamin intakes.

Quantitation of plasma thiamine, related metabolites and plasma protein oxidative damage markers in children with autism spectrum disorder and healthy controls

Aims/hypothesis: To assess thiamine and related metabolite status by analysis of plasma and urine in autistic children and healthy controls, correlations to clinical characteristics and link to plasma protein markers of oxidative damage.Methods: 27 children with autism (21 males and 6 females) and 21 (15 males and 6 females) age-matched healthy control children were recruited. The concentration of thiamine and related phosphorylated metabolites in plasma and urine and plasma protein content of dityrosine, N-formylkynurenine and 3-nitrotyrosine was determined.Results: Plasma thiamine and thiamine monophosphate concentrations were similar in both study groups (median [lower–upper quartile]): autistic children – 6.60 nM (4.48–8.91) and 7.00 nM (5.51–8.55), and healthy controls – 6.82 nM (4.47–7.02) and 6.82 nM (5.84–8.91), respectively. Thiamine pyrophosphate (TPP) was decreased 24% in autistic children compared to healthy controls: 6.82 nM (5.81–8.52) versus 9.00 nM (8.41–10.71), p < .01. Urinary excretion of thiamine and fractional renal clearance of thiamine did not change between the groups. No correlation was observed between clinical markers and the plasma and urine thiamine concentration. Plasma protein dityrosine content was increased 88% in ASD. Other oxidative markers were unchanged.Conclusions/interpretation: Autistic children had normal plasma and urinary thiamine levels whereas plasma TPP concentration was decreased. The latter may be linked to abnormal tissue handling and/or absorption from gut microbiota of TPP which warrants further investigation. Increased plasma protein dityrosine may reflect increased dual oxidase activity in response to change in mucosal immunity and host–microbe homeostasis.

Regular moderate exercise training can alter the urinary excretion of thiamin and riboflavin.

BACKGROUND/OBJECTIVESPhysical exercise promotes energy producing pathways requiring thiamin and riboflavin as a coenzyme. Therefore, this study investigated the effects of regular exercise training on urinary excretion of thiamin and riboflavin.MATERIALS/METHODSFifty rats were randomly assigned to one of two groups: non-exercise training (NT, n = 25) and regular exercise training (ET, n = 25) for 5 weeks. The rats performed moderate exercise on a treadmill (0.5-0.8 km/hour) for 30 min/day, 5 days/week. Twenty-four hour urine samples were collected at the end of the 0 week, 3rd week, and 5th week of training and thiamin and riboflavin were analyzed.RESULTSNo significant differences in thiamin and riboflavin intakes for each week were observed between the NT and ET groups. Urinary thiamin excretion of each group was the highest at the 5th week compared to the levels at 0 and 3rd week. Urinary thiamin at the 5th week was significantly lower in the ET group than in the NT group. Urinary riboflavin excretion was increased by training duration, however, no difference was observed between NT and ET for each week. At 0 and 3rd week, no significant relationships were observed between dietary intake and urinary excretion of thiamin and riboflavin, however, at the 5th week, urinary excretion was significantly increased by dietary intake only in the NT group (P < 0.05). Thiamin excretion of both NT and ET groups was significantly increased with riboflavin excretion at the 5th week (P < 0.01).CONCLUSIONRegular moderate exercise training increased urinary excretion of thiamin. Dietary intakes and urinary excretions of thiamin and riboflavin showed positive correlation in both the exercise training and non-exercise training groups as the exercise training period went by, while the correlations in the exercise training group were weaker than those in the non-exercise training group. Therefore, regular exercise training can alter the urinary excretion of thiamin and riboflavin in rats.

Shoshin beriberi induced by long-term administration of diuretics: a case report.

Previous studies have suggested that diuretic therapy for heart failure may lead to thiamine deficiency due to the increased urinary thiamine excretion. Herein, we present the case of a 61-year-old man with shoshin beriberi, a fulminant form of wet beriberi, induced by long-term diuretic therapy. The patient had a history of heart failure with preserved ejection fraction and was receiving furosemide and trichlormethiazide therapy. He presented with worsening exertional dyspnea and was admitted for heart failure exacerbation. His condition failed to improve even after intensive treatment. A hemodynamic evaluation with the Swan-Ganz catheter revealed high-output heart failure with low peripheral vascular resistance. Thiamine was administered for suspected shoshin beriberi; his hemodynamic status improved dramatically within the next six hours. The serum thiamine level was below the normal range; the patient was therefore diagnosed with shoshin beriberi. The common causes of thiamine deficiency were not identified. Long-term diuretic therapy with furosemide and thiazide was thought to have played a major role in the development of thiamine deficiency. This case illustrates the importance of considering wet beriberi as a possible cause of heart failure exacerbation in patients taking diuretics, even when the common thiamine deficiency causes are not identified with history-taking.

Investigation of Endogenous Compounds for Assessing the Drug Interactions in the Urinary Excretion Involving Multidrug and Toxin Extrusion Proteins

Multidrug and toxin extrusion proteins (MATEs) are multispecific organic cation transporters mediating the efflux of various cationic drugs into the urine. The present study aimed at identifying endogenous compounds in human plasma and urine specimens as biomarkers to evaluate drug interactions involving MATEs in the kidney without administration of their exogenous probe drugs. An untargeted metabolomic analysis was performed using urine and plasma samples from healthy volunteers and mice treated with or without the potent MATE inhibitor, pyrimethamine. Plasma and urinary concentrations of candidate markers were measured using liquid chromatography-mass spectrometry. Transport activities were determined in MATE- or OCT2-expressing HEK293 cells. The deuterium-labeled compounds of candidates were administered to mice for pharmacokinetics study. Urinary excretion of eleven compounds including thiamine and carnitine was significantly lower in the pyrimethamine-treatment group in humans and mice, whereas no endogenous compound was noticeably accumulated in the plasma. The renal clearance of thiamine and carnitine was decreased by 70%-84% and 90%-94% (p < 0.05), respectively, in human. The specific uptake of thiamine was observed in MATE1-, MATE2-K- or OCT2-expressing HEK293 cells with Km of 3.5 ± 1.0, 3.9 ± 0.8 and 59.9 ± 6.7μM, respectively. The renal clearance of carnitine-d 3 was decreased by 62% in mice treated with pyrimethamine. Our findings indicate that MATEs account for the efflux of thiamine and perhaps carnitine as well as drugs into the urine. The urinary excretion of thiamine is useful to detect drug interaction involving MATEs in the kidney.

Thiamin Status and Supplementation in the Management of Diabetes Mellitus and its Vascular Comorbidities

The water soluble B vitamin, thiamin, in its coenzyme form as thiamin pyrophosphate (TPP), is necessary for key reactions in glucose metabolism. For this reason, associations between thiamin status or thiamin supplementation and diabetes have been the focus of recent research. Currently, it is not clear how occurrence of diabetes relates to parameters of thiamin status, such as plasma thiamin levels. However, there is strong evidence that the diabetic state increases urinary thiamin excretion and decreases the activity of transketolase (TK), a TPP-dependent enzyme of the hexose monophosphate (HMP) shunt in various body tissues. Impairment of TK activity and subsequent downregulation of the HMP shunt activates several pathways that contribute to vascular damage and development of diabetes-related comorbidities such as retinopathy, cardiomyopathy, and nephropathy. Thiamin supplementation has been shown to be effective in restoring TK activity in animal models of diabetes, and in type 1 and type 2 diabetic individuals. Thiamin supplementation has also been shown to be effective in preventing or reversing, either partially or completely, hyperglycemia-induced damage to vascular endothelial cells, and microalbuminuria associated with diabetic nephropathy. Here, we review from current literature examining the relationship between diabetes and thiamin status as well as intervention trials evaluating the effect of thiamin supplementation on glycemic control and prevention of vascular comorbidities of diabetes.

Effect of High Dose Thiamine Therapy on Risk Factors in Type 2 Diabetics

Background: Traditional and more recently, a host of nontraditional risk factors of type 2 diabetes mellitus have adopted significance as promoters of the pathologies associated with this disease. High dose Vitamin B1 (thiamine) has been found at preclinical level to play an ameliorative role through a number of intracellular metabolic pathways. In order to demonstrate this clinically, pioneering research on the effect of high dose thiamine on associated markers of biochemical dysfunction, incipient diabetic nephropathy, hemostasis (plasminogen activation inhibitor/PAI-1), oxidative stress (plasma thiols) and second messenger signaling (protein kinase C/ PKC ) was conducted. Subjects and methods: Type 2 diabetics were enrolled in randomized, double blind placebo controlled clinical trial for 6 months. Patients were divided into two groups and administered 300 mg/day thiamine or placebo for 3 months, followed by a 2 month washout period. Normal healthy controls participated for baseline estimations only. Plasma and urinary thiamine levels, microalbuminuria, PAI-1, oxidative stress marker plasma thiols were estimated. The messenger signaling PKC profile was determined in normal controls and in type 2 diabetics. Results: Lower plasma thiamine concentration of diabetic patients was observed as compared to normal subjects. Thiamine treatment increased thiamine concentration and urinary thiamine excretion and reduced significantly microalbuminuria and glycated hemoglobin. Type 2 diabetics had significantly higher PAI-1 and PKC levels as compared to normal controls. Following 3 months thiamine therapy, PAI-1 remained unchanged, while levels of PKC were reduced significantly in thiamine treated diabetics and lowered after discontinuing the drug. While in placebo group significant increase in PKC levels persisted during the whole period. Oxidative stress marker, plasma thiols was reduced significantly in diabetics versus normal controls with no change occurring following thiamine or placebo therapy. Conclusion: Thiamine therapy significantly improved micoalbuminuria, glycated hemoglobin, thiamine status and decreased PKC levels with no significant impact on oxidative stress and fibrinolysis profile.

Blood thiamine and its phosphate esters as measured by high-performance liquid chromatography: levels and associations in diabetes mellitus patients with varying degrees of microalbuminuria.

Thiamine deficiency has been linked to microvascular complications in patients with diabetes mellitus (DM). In this study, we aim to assess blood and urine thiamine status by high performance liquid chromatography (HPLC) in patients with DM Type 1 and Type 2 (DMT1, DMT2) and to identify associations with markers of incipient nephropathy and kidney dysfunction. A total of 205 subjects (43 DMT1 and 162 DMT2) with and without microalbuminuria and 26 non-diabetic controls were included. Fasting blood samples were collected and anthropometric parameters were measured. Fasting blood, lipid and renal profile were determined routinely. Blood thiamine concentration, its phosphate esters and urine thiamine were quantified using HPLC. Blood thiamine concentrations (ng 1-1) were decreased by 75.7% and 49.6% in patients with DMT1 and DMT2, respectively [controls (54.8+/-11.4); DMT1 (41.5+/-17.9); DMT2 (27.2+/-12.7), p<0.001]. Among those with normo-albuminuria, urinary excretion of thiamine was significantly increased to 390.1 microg/ml and 1212.4 microg/ml in DMT1 and DMT2 respectively, as compared to controls (326.4 microg/ml). DMT1 and DMT2 patients with micro- albuminuria on the other hand had 2.5- and 3.4-fold increase in urinary excretion of thiamine compared to controls. Low levels of blood thiamine are present in patients with DMT1 and DMT2, and are associated with increased thiamine clearance.

Thiamine supplementation in symptomatic chronic heart failure: a randomized, double-blind, placebo-controlled, cross-over pilot study

Diuretic treatment for heart failure may lead to an increased urinary thiamine excretion and in long-term thiamine deficiency, which may further compromise cardiac function. This study evaluated the effect of high dose thiamine supplementation in heart failure patients. Nine patients with diuretic treatment for symptomatic chronic heart failure and a left ventricular ejection fraction (LVEF) <40% were randomly assigned to receive thiamine (300mg/day) or placebo for 28days. After a wash-out of 6weeks, the patients crossed-over to a second treatment period. The primary outcome was a change in LVEF. Mean age was 56.7±9.2years (range 44.9-75.4years). Baseline LVEF was similar for both treatment groups (29.5% in the thiamine group and 29.5% in the placebo group, P=0.911). After 28days of thiamine treatment, the LVEF increased to 32.8% which was significantly (P=0.024) different from the LVEF in the placebo group (28.8%). This corresponds to a treatment effect for LVEF of 3.9% in absolute terms. This study suggests that thiamine supplementation has beneficial effects on cardiac function in patients with diuretic drugs for symptomatic chronic heart failure. Subclinical thiamine deficiency is probably an underestimated issue in these outpatients.

Effect of Fasting on the Urinary Excretion of Water-Soluble Vitamins in Humans and Rats

Recent studies showed that the urinary excretion of the water-soluble vitamins can be useful as a nutritional index. To determine how fasting affects urinary excretion of water-soluble vitamins, a human study and an animal experiment were conducted. In the human study, the 24-h urinary excretion of water-soluble vitamins in 12 healthy Japanese adults fasting for a day was measured. One-day fasting drastically decreased urinary thiamin content to 30%, and increased urinary riboflavin content by 3-fold. Other water-soluble vitamin contents did not show significant change by fasting. To further investigate the alterations of water-soluble vitamin status by starvation, rats were starved for 3 d, and water-soluble vitamin contents in the liver, blood and urine were measured during starvation. Urinary excretion of thiamin, riboflavin, vitamin B(6) metabolite 4-pyridoxic acid, nicotinamide metabolites and folate decreased during starvation, but that of vitamin B(12), pantothenic acid and biotin did not. As for blood vitamin levels, only blood vitamin B(1), plasma PLP and plasma folate levels decreased with starvation. All water-soluble vitamin contents in the liver decreased during starvation, whereas vitamin concentrations in the liver did not decrease. Starvation decreased only concentrations of vitamin B(12) and folate in the skeletal muscle. These results suggest that water-soluble vitamins were released from the liver, and supplied to the peripheral tissues to maintain vitamin nutrition. Our human study also suggested that the effect of fasting should be taken into consideration for subjects showing low urinary thiamin and high urinary riboflavin.

Diuretics and vitamin B1: are diuretics a risk factor for thiamin malnutrition?

Despite modern pharmacologic agents in the therapy of heart failure, the prevalence of heart failure is increasing worldwide. In the vitamin B1 deficiency disease beriberi, cardiac symptoms may represent the central feature. Two new studies confirmed that all diuretics lead to increased urinary thiamin excretion depending on the urinary flow rate. In a subject at risk, such as an elderly patient, chronic diuretic treatment may lead to a subclinical thiamin deficiency. Whether subclinical thiamin nutriture is a modulator of the prevalence and/or severity of heart failure is not known; however, it seems to be plausible from the metabolic point of view.

Influence of Probiotic and Conventional Yoghurt on the Status of Vitamins B1, B2 and B6 in Young Healthy Women

Background: In vitro studies indicate that yoghurt bacteria are able to generate several water-soluble vitamins and therefore yoghurt could be a good source of these micronutrients. However, whether lactobacilli or other viable bacteria release the synthesized vitamins or utilize vitamins from their surroundings is a matter of debate. This study was carried out to investigate whether probiotic and traditional yoghurt bacteria are able to influence the status of different B vitamins (B₁, B₂, B₆) in young healthy women. Methods: In this investigation, female volunteers consumed 100 g/day of probiotic (n = 17) or conventional yoghurt (n = 16) for 2 weeks (T1–T2) and 200 g/day for another 2 weeks (T2–T3). A wash-out phase lasting 2 weeks followed. Plasma and urine concentrations of thiamine (vitamin B₁), riboflavin (B₂) and pyridoxine (B₆) were analyzed using HPLC. The functional parameters, i.e. the erythrocyte transketolase (α-ETK) expressed as TPP (thiamine pyrophosphate) effect, erythrocyte glutathione reductase (α-EGR) and glutamic oxaloacetic transaminase (α-EGOT) were determined photometrically. Results: The plasma levels of vitamin B₁ increased significantly in both the probiotic (p < 0.001) and the control group (p < 0.01) when consuming 200 g yoghurt/day (T2–T3) and decreased to the baseline levels after the wash-out phase (T3–T4). Urinary excretion of thiamine and the TPP effect did not significantly change in either the probiotic or the control group during the period of daily yoghurt consumption (T1–T3). The plasma concentration of flavin adenine dinucleotide (FAD) decreased significantly (p < 0.001) after consuming 100 g yoghurt/day (T1–T2) while plasma concentrations of flavin mononucleotide (FMN) (probiotic: p < 0.01, control: p < 0.001) and free riboflavin increased significantly (probiotic: p < 0.01, control: p < 0.001). Afterwards, the levels of these parameters remained unchanged to the end of the study in both tested groups. The urinary excretion of riboflavin and α-EGR remained unaffected throughout the study in both the probiotic and the control group. The average status of vitamin B₆, evaluated by its plasma level, urinary excretion and α-EGOT was unaffected by daily intake of 100 g (T1–T2) and 200 g yoghurt (T2–T3), respectively, for 4 weeks (T1–T3). Conclusion: The results of the present study indicate that daily consumption of 200 g of both, probiotic and conventional yoghurt for 2 weeks can contribute to the total intake of vitamin B₁ and B₂ reflected by increased levels of plasma thiamine and free riboflavin in healthy women. The diminished plasma FAD and increased FMN concentrations, observed during the period of daily yoghurt consumption in both groups, may be the result of enhanced immune function and an oxidant/antioxidant imbalance, caused by the daily intake of lactic acid bacteria. Since the long term status parameters of all three investigated vitamins (B₁, B₂, B₆) remained unaffected during the investigation the changes in plasma concentrations seem more likely the result of regular yoghurt consumption as a fermented dairy product, rather than of the specific intake of probiotic bacteria.

Age-Related Alterations of B-Group Vitamin Contents in Urine, Blood and Liver from Rats

To investigate how aging alters B-group vitamin metabolism, rats were fed with niacin-free 20% casein diet from 3 to 80 wk old, and the urinary excretions of the B group vitamins were periodically measured. The blood and liver B-group vitamin levels in 80-wk-old rats were also compared with those in 8-wk-old rats. The urinary excretion of thiamin, riboflavin, vitamin B6 metabolite 4-pyridoxic acid, pantothenic acid, folic acid and biotin were not altered during 540 d. The urinary vitamin B12 increased by 8-fold at 29 wk old, and further increased at 80 wk old. Conversion of nicotinamide from tryptophan gradually decreased to 60% from 29 to 48 wk old. Plasma PLP, vitamin B12 and folate levels in 80-wk-old rats were lower than those in 8-wk-old rats, consistent with lower liver vitamin B6 and folate levels in aged rats. Plasma and liver biotin levels in aged rats were higher than those in young rats. Other B-group vitamins such as vitamin B1, vitamin B2, niacin and pantothenic acid levels in blood and liver from aged rats were same as those from young rats. Alteration of vitamin B6 metabolism in particular is similar to the observations in elderly humans reported previously. Our findings suggest that aged rats can be useful models to investigate aging-related B-group vitamin metabolism.

High prevalence of low plasma thiamine concentration in diabetes linked to a marker of vascular disease

Aims/hypothesisTo assess thiamine status by analysis of plasma, erythrocytes and urine in type 1 and type 2 diabetic patients and links to markers of vascular dysfunction.MethodsDiabetic patients (26 type 1 and 48 type 2) with and without microalbuminuria and 20 normal healthy control volunteers were recruited. Erythrocyte activity of transketolase, the concentrations of thiamine and related phosphorylated metabolites in plasma, erythrocytes and urine, and markers of metabolic control and vascular dysfunction were determined.ResultsPlasma thiamine concentration was decreased 76% in type 1 diabetic patients and 75% in type 2 diabetic patients: normal volunteers 64.1 (95% CI 58.5–69.7) nmol/l, type 1 diabetes 15.3 (95% CI 11.5–19.1) nmol/l, p < 0.001, and type 2 diabetes 16.3 (95% CI 13.0–9.6) nmol/l, p < 0.001. Renal clearance of thiamine was increased 24-fold in type 1 diabetic patients and 16-fold in type 2 diabetic patients. Plasma thiamine concentration correlated negatively with renal clearance of thiamine (r = −0.531, p < 0.001) and fractional excretion of thiamine (r = −0.616, p < 0.001). Erythrocyte transketolase activity correlated negatively with urinary albumin excretion (r = −0.232, p < 0.05). Thiamine transporter protein contents of erythrocyte membranes of type 1 and type 2 diabetic patients were increased. Plasma thiamine concentration and urinary excretion of thiamine correlated negatively with soluble vascular adhesion molecule-1 (r = −0.246, p < 0.05, and −0.311, p < 0.01, respectively).Conclusions/interpretationLow plasma thiamine concentration is prevalent in patients with type 1 and type 2 diabetes, associated with increased thiamine clearance. The conventional assessment of thiamine status was masked by increased thiamine transporter content of erythrocytes.

Loop Diuretic Therapy, Thiamine Balance, and Heart Failure

Thiamine, or vitamin B1, is a water-soluble B complex vitamin that was first discovered in 1910 in the process of exploring how rice bran cured patients of beriberi. Thiamine is not synthesized in humans, therefore its availability for necessary cellular processes hinges on its continual ingestion. The amount of thiamine one needs to ingest to maintain balance is disease state-dependent or medication-dependent. Severe chronic thiamine deficiency can have significant neurologic and cardiac effects, the latter is reflected in a particular type of heart failure called wet beriberi. This form of heart failure clearly benefits from thiamine supplementation. It is unclear, however, whether thiamine supplementation offers any benefit in other forms of heart failure. Despite this, it is not unreasonable for heart failure patients to routinely ingest a thiamine-containing multivitamin; patients using diuretics have an increased urinary excretion of thiamine and thus are at a higher risk for developing thiamine deficiency. The role of thiamine in heart failure, however, remains arguable.