Compendium of the most significant studies with reference to properties, intake, effects.

Kim HH, Kang YR, Choi HY, Lee JY, Oh JB, Kim JS, Kim YC, Lee KW, Kwon YI. Postprandial anti-hyperglycemic effect of vitamin B6 (pyridoxine) administration in healthy individuals. Food Sci Biotechnol. 2019 Jan 4;28(3):907-911. doi: 10.1007/s10068-018-0534-7. 

Abstract. Postprandial blood glucose lowering effect of vitamin B6 (pyridoxine) was evaluated in healthy individuals with normal blood glucose levels. Blood glucose levels were measured every 30 min for 2 h after oral sugar administration with or without 50 mg of pyridoxine. Pyridoxine significantly lowered the postprandial blood glucose levels at 30 min (from 165.95 ± 17.19 to 138.36 ± 20.43, p < 0.01) and 60 min (from 131.40 ± 17.20 to 118.50 ± 15.95) after administration. In addition, the area under the concentration-time curve (AUCt) was reduced by about 8.3% (from 257.08 ± 22.38 to 235.71 ± 12.33, p < 0.05) and the maximum concentration of blood glucose (Cmax) was reduced by about 13.8% (from 165.95 ± 17.19 to 143.07 ± 11.34, p < 0.01) when compared with those of the control group. Our findings suggest that pyridoxine supplementation may be beneficial for controlling postprandial hyperglycemia.

Shevchuk SV, Postovitenko KP, Iliuk IA, Bezsmertna HV, Bezsmertnyi YO, Kurylenko IV, Biloshytska AV, Baranova IV. The relationship between homocysteine level and vitamins B12, B9 and B6 status in patients with chronic kidney disease. Wiad Lek. 2019;72(4):532-538. 

Abstract. Objective: Introduction: According to present knowledge, hyperhomocysteinemia is one of the risk factors of cardio-vascular pathology. Patients with chronic kidney disease are known to develop hyperhomocysteinemia more often than those in general population. Іmportant cause of hyperhomocysteinemia is the deficiency of vitamins В6, В9 and В12 that are involved in homocysteine metabolism. Vitamins deficiency, we believe, can be one of the causes of hyperhomocysteinemia in the patients with chronic renal failure. The aim: To analyze the plasma homocysteine level in patients with chronic kidney disease and its assosiation with the levels of vitamins B6, B9, B12 in Ukraine....Conclusion: Conclusions: The obtained data are promising for finding effective means of correction of hyperhomocysteinemia in patients with chronic kidney disease by normalizing the vitamin status of such patients.

Demirdas E, Atilgan K. Addition of Vitamin B Complex to Prime Solution in Cobalamin-Deficient Patients to Prevent Postoperative Delirium. Heart Surg Forum. 2019 Feb 25;22(2):E082-E087. doi: 10.1532/hsf.2171.

Abstract. Objective: In this study, we investigated whether the addition of vitamin B complex to prime solution for cardiopulmonary bypass (CPB) in cobalamin-deficient patients undergoing on-pump coronary artery bypass grafting (CABG) helps prevent the development of postoperative delirium (POD)....Conclusion: On the basis of the results of our study, the addition of vitamin B complex to the prime solution for CPB decreases the incidence of POD in cobalamin-deficient patients undergoing on-pump CABG.

Anderson J, Arboleda N, Calleo V. High-Fidelity Simulation Scenario: Pyridoxine-Dependent Epilepsy and Treatment. MedEdPORTAL. 2018 Sep 21;14:10753. doi: 10.15766/mep_2374-8265.10753. 

Abstract. Introduction: Treatment of seizures in the neonatal patient is urgent and time sensitive. Effective and timely treatment of this life-threatening condition is vital in preventing mortality and long-term morbidity. This simulation-based curriculum involves the identification and management of a seizure in a 4-day-old neonate with pyridoxine-dependent epilepsy. The target audience is emergency medicine and pediatric residents, pediatric emergency medicine fellows, and medical students. Methods: The primary objectives for this simulation are to (1) rapidly initiate stabilization techniques for a seizing neonate, (2) recognize the importance of checking a glucose level in a seizing neonate, (3) demonstrate understanding of antiepileptic medications and dosing, and (4) identify status epilepticus and initiate pyridoxine once initial seizure management has failed. The goals of this simulation are for residents to treat a seizing infant in an emergency department setting, identify status epilepticus, develop a differential diagnosis that includes vitamin B6 deficiency, and correctly administer pyridoxine. Requirements of this simulation include a high-fidelity patient simulator, medical supplies, a patient simulator operator, and one actor....Discussion: This simulation case was well received and helped residents develop a systematic approach to seizure management of a newborn. Residents reported increased confidence in treating a seizing neonate and increased comprehension of pyridoxine-dependent epilepsy.

Wempe MF, Kumar A, Kumar V, Choi YJ, Swanson MA, Friederich MW, Hyland K, Yue WW, Van Hove JLK, Coughlin CR 2nd. Identification of a novel biomarker for pyridoxine-dependent epilepsy: Implications for newborn screening. J Inherit Metab Dis. 2019 May;42(3):565-574. doi: 10.1002/jimd.12059. 

Abstract. Pyridoxine-dependent epilepsy (PDE) is often characterized as an early onset epileptic encephalopathy with dramatic clinical improvement following pyridoxine supplementation. Unfortunately, not all patients present with classic neonatal seizures or respond to an initial pyridoxine trial, which can result in the under diagnosis of this treatable disorder. Restriction of lysine intake and transport is associated with improved neurologic outcomes, although treatment should be started in the first year of life to be effective. Because of the documented diagnostic delay and benefit of early treatment, we aimed to develop a newborn screening method for PDE. Previous studies have demonstrated the accumulation of Δ1 -piperideine-6-carboxylate and α-aminoadipic semialdehyde in individuals with PDE, although these metabolites are unstable at room temperature (RT) limiting their utility for newborn screening. As a result, we sought to identify a biomarker that could be applied to current newborn screening paradigms. We identified a novel metabolite, 6-oxo-pipecolate (6-oxo-PIP), which accumulates in substantial amounts in blood, plasma, urine, and cerebral spinal fluid of individuals with PDE. Using a stable isotope-labeled internal standard, we developed a nonderivatized liquid chromatography tandem mass spectrometry-based method to quantify 6-oxo-PIP. This method replicates the analytical techniques used in many laboratories and could be used with few modifications in newborn screening programs. Furthermore, 6-oxo-PIP was measurable in urine for 4 months even when stored at RT. Herein, we report a novel biomarker for PDE that is stable at RT and can be quantified using current newborn screening techniques. © 2019 SSIEM.

Mikkelsen K, Apostolopoulos V. B Vitamins and Ageing. Subcell Biochem. 2018;90:451-470. doi: 10.1007/978-981-13-2835-0_15. 

Abstract. Vitamin B contributes to the overall health and wellbeing, including that of energy metabolism, methylation, synthesis and DNA repair and proper immune function. Deficiency in B vitamins has been linked to neurocognitive disorders, mitochondrial dysfunction, immune dysfunction and inflammatory conditions. In ageing populations B vitamin deficiency has been linked to cardiovascular disorders, cognitive dysfunction, osteoporosis and methylation disorders and can increase the risk of developing degenerative diseases, particularly cardiovascular disease, cognitive diseases and osteoporosis. Optimization of B vitamin status in the elderly may prove beneficial in the prevention of degenerative diseases. Here we discuss broadly the role of B vitamins in ageing.

Wilson MP, Plecko B, Mills PB, Clayton PT. Disorders affecting vitamin B6 metabolism. J Inherit Metab Dis. 2019 Jul;42(4):629-646. doi: 10.1002/jimd.12060. 

Abstract. Vitamin B6 is present in our diet in many forms, however, only pyridoxal 5'-phosphate (PLP) can function as a cofactor for enzymes. The intestine absorbs nonphosphorylated B6 vitamers, which are converted by specific enzymes to the active PLP form. The role of PLP is enabled by its reactive aldehyde group. Pathways reliant on PLP include amino acid and neurotransmitter metabolism, folate and 1-carbon metabolism, protein and polyamine synthesis, carbohydrate and lipid metabolism, mitochondrial function and erythropoiesis. Besides the role of PLP as a cofactor B6 vitamers also play other cellular roles, for example, as antioxidants, modifying expression and action of steroid hormone receptors, affecting immune function, as chaperones and as an antagonist of Adenosine-5'-triphosphate (ATP) at P2 purinoceptors. Because of the vital role of PLP in neurotransmitter metabolism, particularly synthesis of the inhibitory transmitter γ-aminobutyric acid, it is not surprising that various inborn errors leading to PLP deficiency manifest as B6 -responsive epilepsy, usually of early onset. This includes pyridox(am)ine phosphate oxidase deficiency (a disorder affecting PLP synthesis and recycling), disorders affecting PLP import into the brain (hypophosphatasia and glycosylphosphatidylinositol anchor synthesis defects), a disorder of an intracellular PLP-binding protein (PLPBP, previously named PROSC) and disorders where metabolites accumulate that inactivate PLP, for example, ALDH7A1 deficiency and hyperprolinaemia type II. Patients with these disorders can show rapid control of seizures in response to either pyridoxine and/or PLP with a lifelong dependency on supraphysiological vitamin B6 supply. The clinical and biochemical features of disorders leading to B6 -responsive seizures and the treatment of these disorders are described in this review. © 2019 The Authors. Journal of Inherited Metabolic Disease published by John Wiley & Sons Ltd on behalf of SSIEM.

Peraza AV, Guzmán DC, Brizuela NO, Herrera MO, Olguín HJ, Silva ML, Tapia BJ, Mejía GB. Riboflavin and pyridoxine restore dopamine levels and reduce oxidative stress in brain of rats. BMC Neurosci. 2018 Nov 9;19(1):71. doi: 10.1186/s12868-018-0474-4. 

Abstract. Background: Neurological disorders suggest that the excitotoxicity involves a drastic increase in intracellular Ca2+ concentrations and the formation of reactive oxygen species. The presence of these free radicals may also affect the dopaminergic system. The aim of this work was to determine if riboflavin (B2) and pyridoxine (B6) provide protection to the brain against free radicals generated by 3-nitropropionic acid (3-NPA) by measuring the levels of dopamine (DA) and selected oxidative stress markers....Conclusion: The results confirm the capacity of 3-NPA to generate oxidative stress. Besides, the study suggests that B2 or B6 vitamins restored the levels of DA and reduced oxidative stress in brain of rats. We believe that these results would help in the study of neurodegenerative diseases.

Li C, Wang R, Hu C, Wang H, Ma Q, Chen S, He Y. Pyridoxine exerts antioxidant effects in cell model of Alzheimer's disease via the Nrf-2/HO-1 pathway. Cell Mol Biol (Noisy-le-grand). 2018 Jul 30;64(10):119-124. .

Abstract. Pyridoxine is a water- soluble pyridine derivative. The effect of pyridoxine in cell models of Alzheimer's disease (AD), and the potential mechanisms involved, are not fully understood. In this study, the anti-AD effects of pyridoxine were studied in an AD cell model using a combination of techniques viz MTT assay, western blotting and assays for reactive oxygen species (ROS). Assays were also carried out to determine the mechanism underlying the antioxidant effects of pyridoxine. The results obtained revealed that pyridoxine exerted a protective potential against AD, attenuated ROS levels, decreased the expressions of cytoplasmic Nrf2, and upregulated whole-cell HO-1 expression. These results suggest that the anti-AD effect of pyridoxine may be attributed to its anti-oxidant property elicited via stimulation of the Nrf2/HO-1 pathway.

Aspy DJ, Madden NA, Delfabbro P. Effects of Vitamin B6 (Pyridoxine) and a B Complex Preparation on Dreaming and Sleep. Percept Mot Skills. 2018 Jun;125(3):451-462. doi: 10.1177/0031512518770326. 

 Abstract. Anecdotal evidence indicates that supplementation with vitamin B6 (pyridoxine) before bed can enhance dream vividness and recall. In a single pilot study, Ebben, Lequerica, and Spielman (2002) found that vitamin B6 had a dose-dependent effect of increasing scores on a composite measure of dream vividness, bizarreness, emotionality, and color. The present research replicated this study using a larger and more diverse sample of 100 participants from across Australia. We conducted a randomized, double-blind, placebo-controlled investigation of the effects on dreaming and sleep of ingesting 240 mg vitamin B6 (pyridoxine hydrochloride) before bed for five consecutive days. We also included an exploratory condition involving a B complex preparation containing a range of B vitamins. We found that vitamin B6 significantly increased the amount of dream content participants recalled but did not significantly affect dream vividness, bizarreness, or color, nor did it significantly affect other sleep-related variables. In contrast, participants in the B complex group showed significantly lower self-rated sleep quality and significantly higher tiredness on waking. We discuss the potential for using vitamin B6 in research on lucid dreaming.