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At least 19 recordsLinked to original sources
PubMed1999

Long-term diuretic therapy in hypertensive patients: effects on serum homocysteine, vitamin B6, vitamin B12, and red blood cell folate concentrations.

BACKGROUND: The effects of chronic diuretic use on serum homocysteine and its metabolic cofactors vitamin B6, vitamin B12, and red blood cell (RBC) folate have not been well studied. METHODS: Blood samples from 17 hypertensive patients receiving long-term diuretic therapy and 17 hypertensive patients not taking diuretics were analyzed for serum homocysteine, vitamin B6, vitamin B12, and RBC folate. RESULTS: The mean serum homocysteine concentration for patients taking diuretics (17.87 +/- 1.72 micromol/L) was significantly higher than the mean serum homocysteine concentration for patients not taking diuretics (10.31 +/- 0.99 micromol/L). The mean RBC folate concentration for patients taking diuretics (281.01 +/- 17.56 ng/mL) was significantly lower than the mean RBC folate concentration for patients not taking diuretics (430.85 +/- 28.58 ng/mL). Serum vitamin B6 and vitamin B12 concentrations were not significantly different between the two groups. CONCLUSIONS: Chronic diuretic use is associated with a significant increase in serum homocysteine concentration, a significant decrease in RBC folate concentration, and no significant change in concentrations of vitamins B6 and B12.

Diuretics↗
PubMed1981

The effects of ascorbic acid, vitamin B6, vitamin B12, and folic acid supplementation on the breast milk and maternal nutritional status of low socioeconomic lactating women.

In this double-blind study, the effects of ascorbic acid, vitamin B6, vitamin B12, and folate supplementation on the maternal nutritional status and vitamin content of breast milk in 16 low socioeconomic lactating women were studied. Nine subjects were administered a commercial multivitamin-multimineral supplement and seven were given placebos. Milk samples were collected four times per day at 4-h intervals from 5 to 7 and 43 to 45 days postpartum. Fasting blood samples were taken from all mothers at the end of each milk collection period. Dietary records of all foods consumed were kept from 4 to 7 and 42 to 45 days postpartum. There were no significant differences in milk or plasma levels of ascorbic acid between the unsupplemented and supplemented groups. Both the EGPT index and milk concentration of vitamin B6 were significantly different (p less than 0.01) between the unsupplemented and supplemented groups. The milk concentrations of vitamin B12 increased significantly (p less than 0.05) in the supplemented group, as did the milk concentrations of folate (p less than 0.01). Because of consistently low levels of dietary vitamin B6 and folic acid in this group of low socioeconomic lactating women, either dietary changes or supplements could be necessary to maintain recommended levels of these vitamins in the womens' breast milk.

Ascorbic Acid↗
PubMed1979

Trace nutrients. 3 Magnesium, copper, zinc, vitamin B6, vitamin B12 and folic acid in the British household food supply.

1. Intakes of magnesium, copper, zinc, vitamin B6, vitamin B12 and folic acid in Britain were calculated by applying the values selected for the 4th edition of McCance and Widdowson's The Composition of Foods (Paul & Southgate, 1978) to the amounts of food recorded in the National Food Survey made during 1976 (Ministry of Agriculture, Fisheries and Food, 1977). 2. National average intakes were (/person per d): Mg 249 mg, Cu 1.51 mg, Zn 9.1 mg, vitamin B6 1.36 mg, vitamin B12 6.6 micrograms free folic acid 105 microgram and total folic acid 190 micrograms. Corresponding intakes (/person) in families with four or more children were 10-20% lower. 3. A comparison of intakes with those recommended in Canada (Department of National Health and Welfare, 1976) and the USA (National Research Council, 1974) or by WHO (1973) indicated that for folic acid average values were particularly low, and only for vitamin B12 were the recommendations significantly exceeded. 4. Contributions from alcoholic drinks and confectionery were also calculated and found, on average, to be significant for cu, vitamin B12 and folic acid. 5. The losses of B-vitamins which might occur on cooking are discussed.

Alcoholic Beverages↗
PubMed1980

The effects of vitamin C, vitamin B6, vitamin B12, folic acid, riboflavin, and thiamin on the breast milk and maternal status of well-nourished women at 6 months postpartum.

The effects of vitamin supplements and/or diet on the vitamin levels in milk of women were determined at 6 months postpartum. Six subjects consumed a daily supplement (Natalins, Mead-Johnson) in addition to a well-balanced diet--supplemented group, and six subjects consumed only a well-balanced diet--nonsupplemented group. The subjects expressed milk for 3 days at 4-hr intervals, 0, 4, 8, and 12 hr after awakening or taking their vitamin supplement. A 4-day diet record, fasting blood sample, and 24-hr urine samples were collected on each subject at 6 months postpartum. Nutrient intake from diet alone did not differ significantly between the two groups except for riboflavin intake which was significantly higher in the supplemented group. The nutritional status of all women indicated excellent dietary intakes, which vitamin supplementation did not alter significantly. Milk concentration of vitamin B6, vitamin B12, folate, thiamin, riboflavin, and vitamin C, did not differ significntly between groups. Thiamin, vitamin B12, and vitamin B6 concentration in the milk did appear to plateau during the day. Vitamin supplementatin at 6 months postpartum did not affect the breast milk concentration or the nutritional status of well-nourished women.

Ascorbic Acid↗
PubMed1985

Vitamin B6, vitamin C and folacin levels in milk from mothers of term and preterm infants during the neonatal period.

Studies of the composition of milk from mothers who deliver prematurely have focused primarily on macronutrients and trace elements while its vitamin composition has received little attention. This study focused on vitamin B6, vitamin C and folacin in preterm (PT) and term (T) milk which are critical to early growth and development. Fifteen PT and twelve T mothers were studied for five 24-h periods during the first month of lactation. Vitamin C levels were higher in PT milk during the first week of lactation whereas folacin levels were similar to T milk. Vitamin B6 levels in PT milk were lower than in T milk throughout the first month postpartum. These findings suggested that the use of PT milk as the sole source of these nutrients is open to question and that during the neonatal period PT infants need supplements of certain micronutrients.

Adult↗
PubMed2005

Folate, vitamin B6, vitamin B12, and vitamin B2 intake, genetic polymorphisms of related enzymes, and risk of colorectal cancer in a hospital-based case-control study in Japan.

We conducted a case-control study to investigate the association of nutrient intake involved in the one-carbon pathway of folate for DNA methylation and DNA synthesis and the related enzyme genetic polymorphisms with colorectal cancer. Cases were 107 patients newly diagnosed with colorectal cancer. Controls were 224 subjects matched with cases by sex, age, and residential area. Nutrient intake was assessed by a self-administered, semiquantitative food-frequency questionnaire. Four genetic polymorphisms-MTHFR C677T and A1298C, MTRR A66G, and ALDH2 Glu487Lys-were determined using blood samples. Odds ratios were calculated using conditional logistic regression analysis adjusted for smoking, alcohol consumption, body mass index, and dietary fiber intake. Although folate intake was inversely associated with colorectal cancer, this association was attenuated after further controlling for dietary fiber intake. Neither vitamin B6, vitamin B12, nor vitamin B2, nor any genetic polymorphism was significantly associated with colorectal cancer. MTRR polymorphism interacted with the association of folate (P for interaction = 0.04) or vitamin (P for interaction = 0.02) with colorectal cancer, although the other polymorphisms did not interact with any nutrient intake. In conclusion, the study did not support the existing hypothesis of gene-nutrient interaction in colorectal carcinogenesis.

Adult↗
PubMed1998

Plasma homocysteine, vitamin B6, vitamin B12 and folic acid in end-stage renal disease during low-dose supplementation with folic acid.

In order to see whether conventional low-dose folic acid supplement along with vitamin B6 and B12 reduces hyperhomocysteinemia in patients with ESRD, we compared the levels of homocysteine, vitamin B6, B12 and folic acid among 3 groups of patients: 44 ESRD patients on hemodialysis with replacement of folic acid, vitamin B6, and B12 (dialysis group); 27 chronic renal failure patients without vitamin replacement (predialysis group); and 17 hypertensive patients without vitamin replacement (control group). Mean plasma total homocysteine concentration was higher in the dialysis (15.5 +/- 6.6 micromol/l) and the predialysis groups (15.7 +/- 4.2 micromol/l) than in the control group (6.2 +/- 1.5 micromol/l) (p < 0.001). However, there was no difference in homocysteine concentrations between the dialysis and predialysis groups. In the control and predialysis groups, the homocysteine concentration showed a reverse correlation with the concentrations of folic acid (r = 0.584, p = 0. 014 for the control group; r = 0.431, p = 0.247 for the predialysis group) and vitamin B12 (r = 0.485, p = 0.049 for the control group; r = -0.562, p = 0.023 for the predialysis group) but not with vitamin B6. In conclusion, plasma folic acid concentrations were 3-4 times higher in the dialysis than in the predialysis group. But these levels of folic acid are not enough to reduce hyperhomocysteinemia in ESRD.

Adult↗
PubMed2003

Chemometrics assisted spectroscopic determination of vitamin B6, vitamin B12 and dexamethasone in injectables.

A spectrophotometric method is described and applied to resolve ternary mixtures of the corticosteroid dexamethasone sodium phosphate and the vitamins B6 and B12. It involves multivariate calibration based on partial least-squares regression. The model was built with UV-vis absorption spectra, and was evaluated by cross-validation on a number of synthetic mixtures. Satisfactory results for both artificial and commercial samples were obtained. A spectrofluorometric method was also developed for the determination of B6 in the presence of vitamin B12 and dexamethasone. The results provided by both methods for pharmaceutical formulations were compared successfully. None of the described procedures require sample pre-treatment steps.

Chemistry, Pharmaceutical↗
PubMed1997

Vitamin B6, vitamin C, and carpal tunnel syndrome. A cross-sectional study of 441 adults.

As part of an ongoing study of carpal tunnel syndrome (CTS) in industry, we measured plasma concentrations of pyridoxal 5'-phosphate (PLP, a measure of vitamin B6 status) and total ascorbate (ASC, a measure of vitamin C status) in 441 adult volunteers from six industries and a university exercise study. In the entire study group and in non-vitamin users (n = 218), there were no significant differences in mean plasma PLP or ASC concentrations between controls (neither symptoms nor slowing), subjects with symptoms only, subjects with median nerve slowing only, or subjects with CTS (symptoms + slowing). In male non-vitamin users (n = 137), there were significant inverse univariate associations between plasma PLP concentration and the prevalence of pain, the frequency of tingling and nocturnal awakening, and the Phalen test result. In this same subgroup, the ASC/PLP ratio was directly associated with the prevalence of pain and nocturnal awakening, and with the frequency of pain, tingling, and nocturnal awakening. In multivariate analyses, plasma ASC concentration predicted more median nerve slowing and confirmed CTS, and vitamin or vitamin interaction variables were independent predictors of 20 CTS-related outcomes. These multivariate relationships often occurred only after adjustment for age, gender, body mass index, serum alkaline phosphatase activity, or tobacco use. We conclude that there are significant relationships between plasma vitamin levels and both components of CTS (specific symptoms and median nerve slowing). The interaction between plasma PLP and ASC appears to be particularly important with respect to symptoms.

Adult↗
PubMed2003

Plasma folate, vitamin B6, vitamin B12, homocysteine, and risk of breast cancer.

BACKGROUND: In several epidemiologic investigations, folate intake has appeared to reduce the elevated risk of breast cancer associated with moderate alcohol consumption. However, data relating plasma folate levels to breast cancer risk are sparse. We investigated the association between plasma folate and other vitamins with breast cancer in a prospective, nested case-control study. METHODS: Blood samples were obtained during 1989 and 1990 from 32 826 women in the Nurses' Health Study who were followed through 1996 for the development of breast cancer. We identified 712 breast cancer case patients and selected 712 individually matched control subjects. Dietary information was obtained using food frequency questionnaires given in 1980, 1984, 1986, and 1990. Logistic regression was used to estimate the relative risks (RRs) of breast cancer (after adjustment for potential risk factors), and a generalized linear model was used to calculate the Pearson correlation coefficients between plasma estimates of folate, vitamin B(6), vitamin B(12), and homocysteine, and intakes of folate, vitamin B(6), and vitamin B(12). All statistical tests were two-sided. RESULTS: The multivariable RR comparing women in the highest quintile of plasma folate with those in the lowest was 0.73 (95% confidence interval [CI] = 0.50 to 1.07; P(trend) =.06). The inverse association between plasma folate and breast cancer risk was highly statistically significant among women consuming at least 15 g/day (i.e., approximately 1 drink/day) of alcohol (multivariable RR = 0.11, 95% CI = 0.02 to 0.59 for highest versus lowest quintile) in contrast with that of women consuming less than 15 g/day (multivariable RR = 0.72, 95% CI = 0.49 to 1.05). The multivariable RR comparing women in the highest quintile of plasma vitamin B(6) levels with those in the lowest quintile was 0.70 (95% CI = 0.48 to 1.02; P(trend) =.09). Plasma vitamin B(12) levels were inversely associated with breast cancer risk among premenopausal women (multivariable RR = 0.36, 95% CI = 0.15 to 0.86 for highest versus lowest quintile) but not among postmenopausal women. Plasma homocysteine was not associated with breast cancer risk. CONCLUSIONS: Higher plasma levels of folate and possibly vitamin B(6) may reduce the risk of developing breast cancer. Achieving adequate circulating levels of folate may be particularly important for women at higher risk of developing breast cancer because of higher alcohol consumption.

Adult↗
PubMed1992

Effect of supplementation with folinic acid, vitamin B6, and vitamin B12 on valproic acid-induced teratogenesis in mice.

The effect of administration of folinic acid, vitamin B6 + vitamin B12, and their combination on valproic acid (VPA)-induced teratogenesis was studied in NMRI mice. VPA (500 mg/kg, sc) was injected on Day 8 of gestation and the vitamins (two dose levels) were injected ip 1 hr before, immediately before, and 1 hr after VPA administration. Folinic acid significantly reduced VPA-induced resorptions (21-24%), and palate, rib, and sternebral malformations. Exencephaly and spina bifida occulta were also reduced (14 and 40%, respectively), but the difference was not statistically significant. On the other hand, vitamin B6 + vitamin B12 significantly reduced VPA-induced exencephaly (23%), spina bifida occulta (80%), palate and rib malformations, kidney abnormalities, and fetal weight retardation. A combination of the three vitamins was effective in reducing VPA-induced exencephaly (23-30%), spina bifida occulta (60%), and palate and rib malformations. The protection against VPA-induced malformations was not complete and was not always dose related, and the reduction in exencephaly rate was only significant in the absence of a reduction in resorption rate. Full-length cleft palate, sternebral malformations, and retarded sternebral and caudal ossification were, however, increased by the high dose of combined vitamin administration. The present study supports the view that VPA-induced teratogenesis may be mediated via an interaction with folate metabolism. Although folinic acid and vitamin B6 + vitamin B12 can effectively reduce VPA malformations, the protection was not complete, which may suggest the involvement of other factors. Furthermore, the dose levels should be carefully chosen since high doses of the combined vitamins can actually increase the incidence of certain defects.

Abnormalities, Drug-Induced↗
PubMed1995

Prevention of myocardial infarction by vitamin B6.

Vitamin B6 is effective in the treatment of carpal tunnel syndrome and related disorders in patients with vitamin B6 deficiency. Hyperhomocysteinemia, a risk factor for atherosclerosis, is associated with deficiencies of vitamin B6, folate, and cobalamin. Patients who were given vitamin B6 for carpal tunnel syndrome and other degenerative diseases were found to have 27% of the risk of developing acute cardiac chest pain or myocardial infarction, compared with patients who had not taken vitamin B6. Among elderly patients of the author (JE) expiring at home, the average age at death from myocardial infarction was 8 years later in those who had taken vitamin B6, compared with those who had not taken vitamin B6. The preventive effect of vitamin B6 on progression of coronary heart disease may be related to increased formation of pyridoxal phosphate, the coenzyme that is required for catabolism of the atherogenic amino acid, homocysteine.

Aged↗
PubMed1977

Thiamin metabolism in vitamin B6 or vitamin B12 deficient rats.

To clarify the effect of pyridoxine (vitamin B6) or vitamin B12 deficiency on thiamine metabolism, the following two experiments were carried out. In experiment 1, rats were separated into two groups. The first group was fed a complete diet and the second group was fed a vitamin B6 and B12 deficient diet for 25 days. The groups were pair fed. In experiment 2 rats were separated into four groups and fed for 25 days. Group 1 was fed a complete diet; group 2, a vitamin B6 deficient diet; group 3, a vitamin B12 deficient diet; group 4, a thiamin deficient diet. Diet intake was restricted to 10 g/day. Fecal thiamin content increased in B6-B12 (vitamin B6 and B12), B6 (vitamin B6), and B12 (vitamin B12) deficient rats as compared to controls. Thiamin levels in blood, sciatic nerve, liver, heart and kidney decreased in B6-B12, B6, and B12 deficient rats.

Animals↗