Trial reportThe American journal of clinical nutrition2015
Pyridoxine supplementation does not alter in vivo kinetics of one-carbon metabolism but modifies patterns of one-carbon and tryptophan metabolites in vitamin B-6-insufficient oral contraceptive users.
Trial report in The American journal of clinical nutrition, 2015. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to trial NCT01128244 (Vitamin B6 Effects on One-Carbon Metabolism), which is not on this map. Cited by 7 papers.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Vitamin B6 Effects on One-Carbon Metabolism
Who cites it
7 citing papers in PubMed, 12 citations in OpenAlex.
- A novel nutritional supplement to reduce plasma homocysteine in nonpregnant women: A randomised controlled trial in The Gambia.PLoS medicine · 2019Trial
- Trimethylamine-N-oxide and its biological variations in vegetarians.European journal of nutrition · 2017Trial
- Vitamin B6 in Elite Athletes: Potential Implications of High Intakes.Sports medicine (Auckland, N.Z.) · 2026Review
- B Vitamins, Glucoronolactone and the Immune System: Bioavailability, Doses and Efficiency.Nutrients · 2023Review
- The acute postprandial response of homocysteine to multivitamin and mineral supplementation with a standard meal is not impaired in older compared to younger adults.European journal of nutrition · 2023Article
- Vitamin BFood & nutrition research · 2023Article
- Review
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
8 authors at 5 institutions in 3 countries.
Funding
Abstract
backgroundLow chronic vitamin B-6 status can occur in a subset of women who use oral contraceptives (OCs) with uncertain metabolic consequences. An insufficiency of cellular pyridoxal 5'-phosphate (PLP), which is the coenzyme form of vitamin B-6, may impair many metabolic processes including one-carbon and tryptophan metabolism.
objectiveWe investigated the effects of vitamin B-6 supplementation on the in vivo kinetics of one-carbon metabolism and the concentration of one-carbon and tryptophan metabolites in vitamin B-6-deficient OC users.
designA primed, constant infusion of [(13)C5]methionine, [3-(13)C]serine, and [(2)H3]leucine was performed on 10 OC users (20-40 y old; plasma PLP concentrations <30 nmol/L) before and after 28 d of supplementation with 10 mg pyridoxine hydrochloric acid/d. In vivo fluxes of total homocysteine remethylation, the remethylation of homocysteine from serine, and rates of homocysteine and cystathionine production were assessed. Targeted metabolite profiling was performed, and data were analyzed by using orthogonal partial least-squares-discriminant analysis and paired t tests adjusted for multiple testing.
resultsPyridoxine supplementation increased the mean ± SD plasma PLP concentration from 25.8 ± 3.6 to 143 ± 58 nmol/L (P < 0.001) and decreased the leucine concentration from 103 ± 17 to 90 ± 20 nmol/L (P = 0.007) and glycine concentration from 317 ± 63 to 267 ± 58 nmol/L (P = 0.03). Supplementation did not affect in vivo rates of homocysteine remethylation or the appearance of homocysteine and cystathionine. A multivariate analysis showed a clear overall effect on metabolite profiles resulting from supplementation. Leucine, glycine, choline, cysteine, glutathione, trimethylamine N-oxide, and the ratios glycine:serine, 3-hydroxykynurenine:kynurenine, 3-hydroxykynurenine:3-hydroxyanthranilic acid, and 3-hydroxykynurenine:anthranilic acid were significant discriminating variables.
conclusionsConsistent with previous vitamin B-6-restriction studies, fluxes of one-carbon metabolic processes exhibited little or no change after supplementation in low-vitamin B-6 subjects. In contrast, changes in the metabolic profiles after supplementation indicated perturbations in metabolism, suggesting functional vitamin B-6 deficiency. This study was registered at clinicaltrials.gov as NCT01128244.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.