B Vitamins Can Reduce Body Weight Gain by Increasing Metabolism-related Enzyme Activities in Rats Fed on a High-Fat Diet.

B vitamins are enzyme cofactors that play an important role in energy metabolism. The aim of this study was to elucidate whether B vitamin administration can reduce body weight (BW) gain by improving energy metabolism-related enzyme activities in rats fed on a highfat diet. Fifty rats were randomly assigned to one of the following five groups: control group (C), including rats fed on standard rat chow; four treatment groups (HO, HI, H2, and H3), in which rats were fed on a high-fat diet. Rats in the HI group were treated daily with 100 mg/kg BW thiamine (VB1), 100 mg/kg BW riboflavin (VB2), and 250 mg/kg BW niacin (VPP); rats in the H2 group were treated daily with 100 mg/kg BW pyridoxine (VB6), 100 mg/kg BW cobalamin (VB12), and 5 mg/kg BW folate (FA); and rats in the H3 group were treated daily with all of the B vitamins administered to the HI and H2 groups. After 12 weeks, the BW gains from the initial value were 154.5±58.4 g and 159.1±53.0 g in the HI and C groups, respectively, which were significantly less than the changes in the HO group (285.2±14.8 g, P<0.05). In the HO group, the plasma total cholesterol (CHO) and triglyceride (TG) levels were 1.59±0.30 mmol/L and 1,55±0.40 mmol/L, respectively, which were significantly greater than those in the HI group (1.19±0.18 mmol/L and 0.76±0.34 mmol/L, respectively, P<0.05). The activities of transketolase (TK), glutathione reductase, and Na+/K+ adenosine triphosphatase were significantly increased in the B vitamin-treated groups and were significantly greater than those in the HO group (P<0.05). Furthermore, the glucose-6-phosphate dehydrogenase, pyruvic acid kinase, and succinate dehydrogenase activities also were increased after treatment with B vitamins. Supplementation with B vitamins could effectively reduce BW gain and plasma levels of lipids by improving energy metabolism-related enzyme activities in rats, thus possibly providing potential benefits to humans.

Benfotiamine reduces genomic damage in peripheral lymphocytes of hemodialysis patients.

Hemodialysis patients have an elevated genomic damage in peripheral blood lymphocytes (PBLs) and an increased cancer incidence, possibly due to accumulation of uremic toxins like advanced glycation end products (AGEs). Because the vitamin B1 prodrug benfotiamine reduces AGE levels in experimental diabetes, and dialysis patients often suffer from vitamin B1 deficiency, we conducted two consecutive studies supplementing hemodialysis patients with benfotiamine. In both studies, genomic damage was measured as micronucleus frequency of PBLs before and at three time-points after initiation of benfotiamine supplementation. AGE-associated fluorescence in plasma, and in the second study additionally, the antioxidative capacity of plasma was analyzed. Benfotiamine significantly lowered the genomic damage of PBLs in hemodialysis patients of both studies independent of changes in plasma AGE levels. The second study gave a hint to the mechanism, as the antioxidative capacity of the plasma of the treated patients clearly increased, which might ameliorate the DNA damage.

Thiamin status during the third trimester of pregnancy and its influence on thiamin concentrations in transition and mature breast milk.

Thiamin deficiency remains an important public health problem in some populations. The aim of the present investigation was to study thiamin status during the third trimester of pregnancy and its influence on the concentration of this vitamin in transition (days 13-14 of lactation) and mature breast milk (day 40 of lactation) in a group of Spanish women. The pregnancies and lactation periods of fifty-one healthy women 18-35 (mean 26.7 (SD 3.7)) years old were monitored. Vitamin intake during the third trimester was determined by recording the consumption of foods over 5 d and of the quantities provided by dietary supplements. Thiamin status during this stage of pregnancy was determined by measuring the activation coefficient of erythrocyte transketolase (alpha-ETK). Milk thiamin content was estimated (in 41% of the subjects) by oxidizing thiamin to thiocrome and measuring fluorescence. Subjects with thiamin intakes above that recommended (group H) had more satisfactory serum alpha-ETK coefficients (1.01 (SD 0.19)) than did those with lower intakes (group L) (1.21 (SD 0.30); P<0.05). Mature milk thiamin concentrations were significantly higher in group H subjects (0.59 (SD 0.44) micromol/l) than group L subjects (0.25 (SD 0.07) micromol/l). Subjects with alpha-ETK coefficients >1.25 in the third trimester had significantly lower mature milk thiamin concentration (0.31 (SD 0.10) micromol/l) than did subjects with more satisfactory alpha-ETK levels at this time (0.55 (SD 0.42) micromol/l; P<0.05). The thiamin status of women can be improved since 25.5% of subjects took less than that recommended and 13.7% showed signs of severe deficiency (alpha-ETK >1.25). The influence of maternal thiamin intake on alpha-ETK coefficients and on mature breast milk thiamin concentration is confirmed.

Postpartum thiamine deficiency in a Karen displaced population.

BACKGROUND: Before its recognition, infantile beriberi was the leading cause of infant death in camps for displaced persons of the Karen ethnic minority on Thailand's western border. OBJECTIVE: This study aimed to document thiamine status in the peripartum period to examine the current supplementation program and the correlation between the clinical manifestations of thiamine deficiency and a biochemical measure of thiamine status. DESIGN: Women were enrolled prospectively at 30 wk of gestation and were followed up weekly until delivery and at 3 mo postpartum. Thiamine supplementation during pregnancy was based on patient symptoms. RESULTS: At 3 mo postpartum, thiamine deficiency reflected by an erythrocyte transketolase activity (ETKA) > or = 1.20% was found in 57.7% (15/26) of mothers, 26.9% (7/26) of whom had severe deficiency (ETKA > 1.25%). No significant associations between ETKA and putative maternal symptoms or use of thiamine supplements were found. CONCLUSIONS: Biochemical postpartum thiamine deficiency is still common in Karen refugee women. This situation may be improved by educating lactating women to reduce their consumption of thiaminase-containing foods and by implementing an effective thiamine supplementation program.

[The effect of cocarboxylase treatment on erythrocyte transketolase and blood thiamine in patients with end stage renal disease undergoing maintenance hemodialysis]. / Wplyw leczenia kokarboksylaza na aktywnosc transketolazy w erytrocytach i stezenie tiaminy we krwi u chorych ze schylkowa niewydolnoscia nerek, leczonych powtarzana hemodializa.

The depressed ETKA in ESRD patients is supposed to be caused and/or aggravated by several factors among which the diminished content of thiamine in blood and/or disturbances of thiamine utilization seem to play the major role. This role stems from the fact that thiamine acts as the cofactor of transketolase. In order to check the therapeutic significance of this relationship we introduced the thiamine pyrophosphoric acid ester chloride (Cocarboxylasum-CC) administration in 25 patients (mHD + CC). Immediately after each HD performance CC was given i.v. during 12 weeks in a doses of 5 mg/kg b.w., 3 times a week. The blood for ETKA value, free and total thiamine in plasma and erythrocytes, as well as, the total protein and albumins/globulins index investigation was drawn before, after 6 and 12 weeks of CC administration, and 3 months after cessation of this therapy. In 10 patients, on maintenance HD nontreated by CC (mHD), the blood was drawn at the same time intervals. Normal values we obtained from 15 healthy volunteers. For ETKA evaluation photocolorimetric method was used, thiamine content in blood was estimated by fluorimetric method. At the beginning of the study the mean value of ETKA, in two examined groups, was found statistically decreased (p < 0.01) when compared with normals. Mean values of thiamine in plasma and erythrocytes were lower but did not differ significantly from those in normals. After 6 weeks of CC administration ETKA value increased, but only after 12 weeks it increased significantly (p < 0.01), reaching normal value. On the other hand, striking increase in plasma thiamine and erythrocyte thiamine levels was observed after 6 weeks of CC administration already (p < 0.01). Three months after cessation of CC administration significant decrease in ETKA value and thiamine level in blood was observed (p < 0.01). ETKA returned to lower value than in normals even in the presence of still high thiamine levels in blood. In mHD patients nontreated by CC the ETKA value and thiamine levels in blood did not change significantly during all periods of study. The nutritional status assessed by total protein and albumins/globulins index did not change in both groups through the study. We conclude, the administration of high doses of CC to ESRD patients on maintenance hemodialysis HD was successful in terms of increasing ETKA value and thiamine levels in blood without any side effects. Thus, supplementation with large doses of CC deserves further study because it promises to be another adjunct in the treatment of potential thiamine deficiency and metabolic disturbances in the course of dialysotherapy.

Prevalence of thiamin deficiency in anorexia nervosa.

OBJECTIVE: Deficiency of thiamin (vitamin B1) causes a range of neuropsychiatric symptoms that resemble those reported in patients with anorexia nervosa (AN) but the prevalence of thiamin deficiency in AN has not been reliably established. This study was designed to investigate the prevalence of thiamin deficiency in AN. METHOD: Thirty-seven patients attending a specialist eating disorders unit and meeting all or some of the DSM-IV criteria for AN were compared with 50 blood donor controls. All subjects underwent measurement of erythrocyte transketolase activation following the addition of thiamin pyrophosphate, the standard biochemical test for thiamin deficiency. Deficiency was defined as a result more than 2 SD above the mean of the control population. RESULTS: Fourteen patients (38%) had results in the deficient range; 7 (19%) met the most stringent published criterion for deficiency. Deficiency was not related to duration of eating restraint, frequency of vomiting, or alcohol consumption. DISCUSSION: Thiamin deficiency may account for some of the neuropsychiatric symptoms of AN and routine screening or supplementation may be indicated.

Bioavailability of water- and lipid-soluble thiamin compounds in broiler chickens.

The bioavailability of thiamin mononitrate, thiamin chloride-hydrochloride and benfotiamin was compared in broiler chickens. A thiamin-deficient diet was supplemented with either 1.8 and 1.5 mg/kg thiamin equivalent as water-soluble salts, or with 1.5 and 1.2 mg/kg thiamin equivalent as benfotiamin, respectively, and fed to 3 replicate groups/treatment for 21 days. Weight gain, feed consumption and feed conversion rate were not significantly affected by solubility or dietary level of thiamin. Likewise, using biochemical indices of thiamin status (erythrocyte transketolase activation coefficient, and thiamin concentrations in blood and liver), no differences were found between the water-soluble thiamin salts, indicating that they have identical potency. In contrast, biochemical indices of thiamin status showed a significantly higher bioavailability for benfotiamin than for the water-soluble sources.

Vitamin B status in patients with chronic fatigue syndrome.

Some patients with chronic fatigue syndrome say they benefit from taking vitamin supplements. We assessed functional status for the B vitamins pyridoxine, riboflavin and thiamine in 12 vitamin-untreated CFS patients and in 18 healthy controls matched for age and sex. Vitamin-dependent activities--aspartate aminotransferase (AST) for pyridoxine, glutathione reductase (GTR) for riboflavin, transketolase (TK) for thiamine--were measured in erythrocyte haemolysates before and after in-vitro addition of the relevant vitamin. For all three enzymes basal activity (U/g Hb) was lower in CFS patients than in controls: AST 2.84 (SD 0.62) vs 4.61 (1.43), P < 0.001; GTR 6.13 (1.89) vs 7.42 (1.25), P < 0.04; TK 0.50 (0.13) vs 0.60 (0.07), P < 0.04. This was also true of activated values: AST 4.91 (0.54) vs 7.89 (2.11), P < 0.001; GTR 8.29 (1.60) vs 10.0 (1.80), P < 0.001; TK 0.56 (0.19) vs 0.66 (0.08), P < 0.07. The activation ratios, however, did not differ between the groups. These data provide preliminary evidence of reduced functional B vitamin status, particularly of pyridoxine, in CFS patients.

Thiamine deficiency is prevalent in a selected group of urban Indonesian elderly people.

This cross-sectional study involved 204 elderly individuals (93 males and 111 females). Subjects were randomly recruited using a list on which all 60-75 y-old-people living in seven sub-villages in Jakarta were included. The usual food intake was estimated using semiquantitative food frequency questionnaires. Hemoglobin, plasma retinol, vitamin B-12, red blood cell folate and the percentage stimulation of erythrocyte transketolase (ETK), as an indicator of thiamine status, were analyzed. Median energy intake was below the assessed requirement. More than 75% of the subjects had iron and thiamine intakes of approximately 2/3 of the recommended daily intake, and 20.2% of the study population had folate intake of approximately 2/3 of the recommended daily intake. Intakes of vitamins A and B-12 were adequate. Biochemical assessments demonstrated that 36.6% of the subjects had low thiamine levels (ETK stimulation > 25%). The elderly men tended to have lower thiamine levels than the elderly women. The overall prevalence of anemia was 28.9%, and the elderly women were affected more than the elderly men. Low biochemical status of vitamins A, B-12 and RBC folate was found in 5.4%, 8.8 % and 2.9% of the subjects, respectively. Dietary intakes of thiamine and folate were associated with ETK stimulation and plasma vitamin B-12 concentration (r = 0.176, P = 0.012 and r = 0.77, P = 0.001), respectively. Results of this study suggest that anemia, thiamine and possibly vitamin B-12 deficiency are prevalent in the elderly living in Indonesia. Clearly, micronutrient supplementation may be beneficial for the Indonesian elderly population living in underprivileged areas.

Enzymic evaluation of thiamin, riboflavin and pyridoxine status of parturient mothers and their newborn infants in a Mediterranean area of Spain.

OBJECTIVE: To determine the biochemical status of thiamin, riboflavin and pyridoxine in parturient mothers and their newborn infants in a Mediterranean region. DESIGN: Transveral study. SETTING: St Joan University Hospital and Faculty of Medicine & Health Sciences, Universitat Rovira i Virgili, Reus, Spain. SUBJECTS: 131 healthy parturient mothers, with normal pregnancies and deliveries in St Joan University Hospital, and their newborn infants. INTERVENTIONS: Erythrocyte haemolysates were prepared from maternal blood at delivery and infants' umbilical cord blood and used to measure micronutrient status using the transketolase, glutathione reductase and aspartate aminotransferase coenzyme stimulation tests. RESULTS: Maternal and infant coenzyme activities were significantly correlated, but infant coenzyme status was better than maternal, with significantly higher basal and stimulated activity (P < 0.001) and significantly lower activation coefficients (P < 0.001). Inadequate thiamin, riboflavin or pyridoxine status occured in 38.2 62.6% (50-82) of the mothers and 3.1-37.4% (4 49) of the infants; 85.2% (46/54), 12.9% (4/31) and 24.1% (12/54) of infants born to mothers with biochemical deficiency of either thiamin, riboflavin or pyridoxine, respectively also had inadequate status. Maternal deficiencies in more than one vitamin further increased the risk of infant thiamin and pyridoxine deficiency. Maternal and infant riboflavin status were significantly correlated with fetal development (e.g. length at birth, P < 0.001). The incidence of thiamin deficiency in paturient mothers in Spain was the highest out of a 12-country comparison. CONCLUSIONS: Inadequate status for each vitamin was evident in mothers and infants. Maternal status of each individual vitamin, but especially riboflavin, was affected by maternal status of the other vitamins. Infant thiamin status was the most adversely affected by maternal deficiencies in more than one vitamin. Infant riboflavin status, however, was apparently protected from adverse maternal status.

Thiamin and riboflavin status of medical inpatients.

Thiamin status was assessed by erythrocyte transketolase activity (ETKA) and thiamin pyrophosphate effect (TPPE) and riboflavin status by erythrocyte glutathione reductase activity (EGRA) and activity coefficient (AC) in 165 medical inpatients in Ramathibodi Hospital. Based on TPPE > 15 per cent, 9 per cent of the medical inpatients had thiamin depletion. Most of them were patients with renal, cardiovascular, hematological and infectious diseases. Based on AC > or = 1.2, 17 per cent of these inpatients had riboflavin depletion. Most of them were patients with pulmonary, cardiovascular and hematological diseases. Only one patient with pulmonary disease had both thiamin and riboflavin depletion. The proportion of thiamin depletion (2/37) in subjects with thiamin supplementation (mean 32.4, median 6, mode 2 md/d) tended to be less than those without (9/98). But, subjects with riboflavin supplementation (mean 3.3, median 4, mode 1 md/d) had the proportion of riboflavin depletion (0/31) significantly (Z-test, p < 0.005) lower than without supplementation (23/104). The data suggested that although the usual dose of vitamin supplementation in medical inpatients is beneficial thiamin depletion can still be present in catabolic patients.

Thiamine status in patients receiving long-term home parenteral nutrition.

OBJECTIVES: Clinical thiamine deficiency can occur in patients receiving total parenteral nutrition (TPN) without thiamine supplementation. Because considerable breakdown of thiamine may occur in the presence of bisulfite-containing amino acid solutions, subclinical thiamine deficiency may develop with the use of these solutions, even with appropriate thiamine supplementation. The current American Medical Association-Food and Drug Administration approved injectable multivitamin formula contains 3 mg of thiamine. This study was undertaken to determine whether this quantity of thiamine is sufficient to avoid clinical thiamine deficiency in long-term home TPN patients with negligible oral thiamine absorption and in the presence of bisulfite-containing amino acid solutions. METHODS: Twenty-four long-term home TPN patients with oral caloric intakes below the norm were evaluated. Seventeen patients suffered from short bowel syndrome or radiation enteritis, and another three had draining gastrostomies that precluded all intestinal absorption. The duration of TPN therapy ranged between 1 and 164 months. Thiamine status was assessed by assaying thiamine pyrophosphate, transketolase activity, and blood thiamine levels. RESULTS: All thiamine pyrophosphate and erythrocyte transketolase activity levels were within the normal range. CONCLUSIONS: This study demonstrates that the currently recommended 3 mg of thiamine hydrochloride added to TPN solutions is adequate to maintain normal thiamine status. This should prevent the development of thiamine deficiency even in patients with compromised intestinal thiamine absorption, and in the presence of bisulfite-containing amino acid solutions.

Biochemical evidence of thiamine depletion during the Cuban neuropathy epidemic, 1992-1993.

During an epidemic outbreak of neuropathy in Cuba during 1992-1993, blood and urine samples were collected from 107 persons with confirmed neuropathy, from 106 control subjects without clinical abnormality who were broadly matched with the affected persons by age and domicile, and from 537 unmatched subjects, also free from clinical abnormality. The unmatched subjects lived in two locations in Cuba; at each location they were drawn from two age ranges: 11-15-y-old secondary school students and 16-64-y-old adults. Measurements of urinary thiamine and blood transketolase and its activation with thiamine pyrophosphate were made. For the neuropathy subjects, these measurements were repeated after 3 wk of rehabilitation. All groups showed biochemical evidence of thiamine depletion affecting 30-70% of their members, which is a high prevalence. Severity of biochemical depletion was, however, no greater in the neuropathy subjects than in the control subjects (P > 0.05). However, it was greater in Pinar del Rio, where the incidence of disease was higher, than in the city of Havana, where less disease was seen. Although the majority of the affected subjects responded biochemically to a daily oral multivitamin supplement containing thiamine (P < 0.001), in some cases normal biochemical status was not achieved even after 3 wk of intensive treatment. In the affected group, thiamine status was inversely correlated with the amount of alcohol consumed (P = 0.007). Thiamine status at the outset was correlated with clinical outcome after treatment. Although neither thiamine depletion nor alcohol abuse were likely to have been the sole cause of the neuropathy epidemic, they may have been contributory factors. Thiamine supplementation or food fortification may therefore be necessary in Cuba.

Thiamin, riboflavin and vitamin B6: impact of restricted intake on physical performance in man.

OBJECTIVE: A combined marginally deficient status of thiamin, riboflavin, vitamin B6 and vitamin C may affect physical performance, but the relative contribution of each vitamin can only be speculated. In a previous study we did not find any effect of restricted intake of vitamin C individually. Therefore, the functional effect of restriction of thiamin, riboflavin or vitamin B6, individually or in conjunction, was investigated. METHODS: A double-blind, 2 x 2 x 2 complete factorial experiment on the effects of thiamin, riboflavin and vitamin B6 restriction on physical performance was executed with 24 healthy men. During 11 weeks of low vitamin intake, the subjects were given a daily diet of regular food products providing no more than 55% of the Dutch Recommended Dietary Allowances (RDA) for thiamin, riboflavin and vitamin B6. Other vitamins were supplemented at twice the RDA level. RESULTS: In vitamin-restricted subjects, blood vitamin levels, erythrocytic enzyme activities and urinary vitamin excretion decreased and in vitro erythrocytic enzyme stimulation increased. Short-time vitamin restriction had no harmful effects on health. A significant overall decrease was observed in aerobic power (VO2-max; 11.6%), onset of blood lactate accumulation (OBLA; 7.0%) and oxygen consumption at this power output (VO2-OBLA; 12.0%), peak power (9.3%), mean power (6.9%) and related variables (p < 0.01). However, the observed performance decrements could not be attributed to marginal deficiency for any of the vitamins studied. CONCLUSION: The absence of vitamin-specific effects on performance decrements due to thiamin, riboflavin and vitamin B6 restriction suggests quantitatively similar but non-additive effects of these B-vitamins on mitochondrial metabolism.

Lack of association between indices of vitamin B1, B2, and B6 status and exercise-induced blood lactate in young adults.

By means of a 5-week vitamin B-complex supplementation, associations between indices of vitamin B1, B2, and B6 status (activation coefficients [AC] for erythrocyte transketolase, glutathione reductase, and aspartate aminotransferase) and exercise-induced blood lactate concentration were studied. Subjects, 42 physically active college students (18-32 yrs), were randomized into vitamin (n = 22) and placebo (n = 20) groups. Before the supplementation there were no differences in ACs or basal enzyme activities between the groups. The ACs were relatively high, suggesting marginal vitamin status. In the vitamin group, all three ACs were lower (p < 0.0001) after supplementation: transketolase decreased from 1.16 (1.14-1.18) (mean and 95% confidence interval) to 1.08 (1.06-1.10); glutathione reductase decreased from 1.33 (1.28-1.39) to 1.14 (1.11-1.17); and aspartate aminotransferase decreased from 2.04 (1.94-2.14) to 1.73 (1.67-1.80). No changes were found after placebo. Despite improved indices of vitamin status, supplementation did not affect exercise-induced blood lactate concentration. Hence no association was found between ACs and blood lactate. It seems that marginally high ACs do not necessarily predict altered lactate metabolism.

Gradual and rapid weight loss: effects on nutrition and performance in male athletes.

We studied seven male wrestlers and three judo athletes (weight 55-93 kg) during two weight reductions. In the "gradual" procedure (GP), a 5.0 +/- 0.4% (mean +/- SEM) weight loss was achieved in 3 weeks by energy restriction. In the "rapid" procedure (RP), 6.0 +/- 0.6% of body weight was lost in 2.4 days by fluid and diet restriction and forced sweating, and followed by a 5-h "loading" (food and drinks ad libitum). The net weight loss after GP and loading was 2.7 +/- 0.5%. Protein intakes (4-d food records) during GP and RP were 71 +/- 16 and RP 56 +/- 17 g.d-1, respectively. Carbohydrate intakes were 239 +/- 56 (GP) and 182 +/- 55 g.d-1 (RP). During GP and RP, mean thiamin, magnesium, and zinc intakes were at or below the respective recommendation. Thiamin, riboflavin, potassium, iron, and zinc status, assessed from blood chemistry, remained stable during both procedures. Changes in vitamin B6 indicator (E-ASTAC) and S-magnesium concentration were different (P < 0.01) between the procedures, suggesting negative trends during GP. Sprint (30-m run) and anaerobic (1-min Wingate test) performance was similar throughout the study. Following GP, vertical jump height with extra load increased by 6-8% (P < 0.01). Jumping results were not affected by RP. Hence, < or = 5% loss in body weight by either method did not impair experienced athletes' performance.

Thiamine, riboflavin, and pyridoxine deficiencies in a population of critically ill children.

The unexpected autopsy finding of Wernicke encephalopathy in three children who died after prolonged enteral feeding prompted us to examine the incidence of thiamine deficiency in three high-risk pediatric populations. We also measured riboflavin and pyridoxine activity in the same groups. We used activated enzyme assays (erythrocyte transketolase, glutathione reductase, aspartate aminotransferase) to assess tissue stores of the dependent vitamin cofactors (thiamine (vitamin B1), riboflavin (vitamin B2), and pyridoxine (vitamin B6), respectively). Using our own reference ranges based on data from 80 healthy adults and children, we prospectively investigated the B vitamin status of three groups of children: (1) 27 patients who were fed solely by nasogastric tube for more than 6 months, (2) 80 children admitted to a pediatric intensive care unit for more than 2 weeks, and (3) 6 children receiving intensive chemotherapy. The upper limits for stimulated enzyme activity in control subjects were unaffected by age or gender (16% for transketolase, 63% for glutathione reductase, 123% for aspartate aminotransferase). Using these limits, 10 (12.5%) of 80 patients receiving intensive care and 4 of 6 patients receiving chemotherapy were thiamine deficient. Elevated levels returned to normal after thiamine supplementation. No patients were pyridoxine deficient, but 3 (3.8%) of the 80 patients receiving intensive care and 1 of the 6 patients receiving chemotherapy were also riboflavin deficient. We conclude that unrecognized thiamine deficiency is common in our pediatric intensive care and oncology groups. This potentially fatal but treatable disease can occur in malnourished patients of any age and is probably underdiagnosed among chronically ill children. Our findings may be applicable to other high-risk pediatric groups.

Hypokalaemic episodic polymyopathy in cats fed a vegetarian diet.

A previously undocumented hypokalaemic condition with a cyclical nature, comprising acute bouts of polymyopathy followed by spontaneous recoveries, is described in the cat. Cats being fed a high protein vegetarian diet developed recurrent episodes of polymyopathy, characterised by ventroflexion of the head and neck, stiff forelimb gait, lateral head-resting and generalised muscle weakness. Plasma potassium concentrations (mean +/- standard deviation) were reduced from 3.28 +/- 0.33 mmol/l at the beginning of the experiment to 2.45 +/- 0.24 mmol/l during bouts of myopathy. This hypokalaemia was associated with increased creatine kinase activities indicative of muscle damage, and decreased urinary potassium concentrations, and was caused by insufficient dietary potassium. Cats that received the same diet supplemented with potassium did not develop hypokalaemic polymyopathy. Spontaneous recoveries of affected cats were not associated consistently with increases in plasma potassium concentrations. Plasma taurine concentrations decreased and glutamic acid increased markedly in all cats fed the experimental diet. There was no evidence of thiamin deficiency associated with the high glutamic acid intake. Veterinarians should be aware that hypokalaemic cats, and in particular those on potassium-deficient diets, may show cyclical disease with episodes of polymyopathy recurring after periods of spontaneous clinical recovery. This condition in cats may be a useful animal model for familial hypokalaemic periodic paralysis in humans.

Thiamin and vitamin B6 intakes and erythrocyte transketolase and aminotransferase activities in morbidly obese females before and after gastroplasty.

To assess the need for postoperative vitamin supplements, intakes and nutritional status of thiamin (B1) and vitamin B6 were studied in 18 female gastroplasty patients who received a placebo or different levels of supplemental vitamins. Postoperative erythrocyte transketolase basal (BA) and thiamin pyrophosphate-stimulated (SA) activities and activity coefficients (AC) correlated significantly with B1 intake. Despite a decrease in apotransketolase, low thiamin intakes were associated with increased AC values during the first 3 months. With return to low B1 intakes following repletion during month 4, the AC values remained normal with low total activities. Both alanine (EALT) and aspartate (EAST) aminotransferase apoenzyme levels declined and AC values increased significantly during the first 3 months. Although the EALT-indices were more sensitive to changes in B6 intake than the EAST-indices, the EASTBA and SA correlated most consistently with the intake. Postoperative dietary intakes of both vitamins were inadequate for maintenance of normal activities of these erythrocyte enzymes. Although B1 intake of greater than or equal to 1.0 mg/day was adequate for maintenance of normal thiamin status in most subjects of this study, supplementation with greater than or equal to 1.5 mg/day is prudent even though it may not prevent the early postoperative loss of apotransketolase. Vitamin B6 intake at the current recommended dietary allowance (1.6 mg) was not adequate to maintain coenzyme saturation of the erythrocyte aminotransferases. Marginal intake of other nutrients may have affected the utilization of both thiamin and vitamin B6.