Search Results (29)

Water-soluble B vitamins, mainly obtained through dietary intake of fruits, vegetables, grains, and dairy products, act as co-factors in various biochemical processes, including DNA synthesis, repair, methylation, and energy metabolism. These vitamins include B1 (Thiamine), B2 (Riboflavin), B3 (Niacin), B5 (Pantothenic Acid), B6 (Pyridoxine), B7 (Biotin), B9 (Folate), and B12 (Cobalamin). Recent studies have shown that besides their fundamental physiological roles, B vitamins influence oncogenic metabolic pathways, including glycolysis (Warburg effect), mitochondrial function, and nucleotide biosynthesis. Although deficiencies in these vitamins are associated with several complications, emerging evidence suggests that excessive intake of specific B vitamins may also contribute to cancer progression and interfere with therapy due to impaired metabolic and genetic functions. This review discusses the tumor-suppressive and tumor-progressive roles of B vitamins in cancer. It also explores the recent evidence on a comprehensive understanding of the relationship between B vitamin metabolism and cancer progression and underscores the need for further research to determine the optimal balance of B vitamin intake for cancer prevention and therapy. Full article

Epileptic and developmental encephalopathies (EDEs) are a group of severe, genetically various neurological conditions characterized by early-onset seizures and developmental impairments. Recent advances in molecular genetics and diagnostic tools have led to the development of precision therapies, aiming to address the deep causes of these disorders. Examples, such as pyridoxine for pyridoxine-dependent epilepsy and the ketogenic diet for GLUT1 deficiency syndrome illustrate the potential of presumed tailored treatments. However, challenges persist, as current therapies often fail to fully mitigate neurodevelopmental impairments. Moreover, traditional phenotype-based management strategies, while effective for seizure control, do not address the root causes of these disorders, underscoring the limitations of existing approaches. This article explores the evolving landscape of precision medicine in EDEs, emphasizing the importance of genetic insights in therapy design and the need for a multidisciplinary approach. It also highlights the barriers to widespread implementation, including diagnostic delays, accessibility, and a lack of robust clinical evidence. To fully realize the potential of precision therapies, comprehensive genetic integration, innovation in treatment, and global collaboration are essential. The future of EDE management lies in therapies that not only control symptoms but also correct genetic and molecular defects, offering a more effective, individualized approach to care. Full article

Background/Objectives: Vitamin and/or mineral supplements are designed to correct micronutrient deficiencies or maintain adequate intake. However, evidence suggests the indiscriminate use of these products, particularly among populations that already meet their micronutrient requirements through diet. This study aims to estimate the prevalence of vitamin and/or mineral supplement use and assess the dietary intake of micronutrients among users and non-users in the Brazilian adult and elderly populations. Methods: The prevalence of vitamin and/or mineral supplement use was estimated from a sample of 37,364 individuals who participated in the Brazilian National Food Survey, a module of the 2017–2018 Household Budget Survey. The average dietary intake of micronutrients—including calcium, magnesium, phosphorus, iron, copper, zinc, vitamin A, thiamine, riboflavin, niacin, cobalamin, pyridoxine, vitamin D, vitamin E, vitamin C, and folate—was calculated for both users and non-users of these supplements, based on 24 h dietary recalls collected during the survey. Analyses of dietary intake were stratified by sex and age group. Results: The estimated overall prevalence of supplement use was 16.0% (95% CI: 15.4–16.6), with a higher prevalence among women (19.5% [95% CI: 18.7–20.5]) and the elderly (27.9% [95% CI: 26.4–29.4]). Women who used vitamin and/or mineral supplements showed higher average intakes for a greater number of dietary micronutrients compared to non-users. Conclusions: The findings from the analysis of average micronutrient intake from food sources, particularly among women and elderly women who used supplements, support the paradox of the “inverse supplement hypothesis”, which suggests that individuals who use dietary supplements are often those with the least need for them. Full article

Background: Cystathione beta-synthase (CBS) T236N is a novel mutation associated with pyridoxine non-responsiveness, which presents a significant difficulty in the medical treatment of homocystinuria. Reported severe phenotypes in homocystinuria patients highlight the urgent requirement to comprehend the molecular mechanisms underlying mutation pathogenicity for the advancement of the disease. Methodology: In this study, we used a multidisciplinary approach to investigate the molecular properties of bacterially expressed and purified recombinant CBS^T236N protein, which we directly compared to those of the wild-type (CBS^WT) protein. Results: Our data revealed a profound impact of the p.T236N mutation on CBS enzymatic activity, with a dramatic reduction of ~96% compared to the CBS^WT protein. Circular dichroism (CD) experiments indicated that the p.T236N mutation did not significantly alter the secondary structure of the protein. However, CD spectra unveiled distinct differences in the thermal stability of CBS^WT and CBS^T236N mutant protein species. In addition, chemical denaturation experiments further highlighted that the CBS^WT protein exhibited greater thermodynamic stability than the CBS^T236N mutant, suggesting a destabilizing effect of this mutation. Conclusions: Our findings provide an explanation of the pathogenicity of the p.T236N mutation, shedding light on its role in severe homocystinuria phenotypes. This study contributes to a deeper understanding of CBS deficiency and may improve the development of targeted therapeutic strategies for affected individuals. Full article

Enzymes reliant on pyridoxal 5′-phosphate (PLP), the metabolically active form of vitamin B₆, hold significant importance in both biology and medicine. They facilitate various biochemical reactions, particularly in amino acid and neurotransmitter metabolisms. Vitamin B₆ is absorbed by organisms in its non-phosphorylated form and phosphorylated within cells via pyridoxal kinase (PLK) and pyridox-(am)-ine 5′-phosphate oxidase (PNPOx). The flavin mononucleotide-dependent PNPOx enzyme converts pyridoxine 5′-phosphate and pyridoxamine 5′-phosphate into PLP. PNPOx is vital for both biosynthesis and salvage pathways in organisms producing B₆ vitamers. However, for those depending on vitamin B₆ as a nutrient, PNPOx participates only in the salvage pathway. Transferring the PLP produced via PNPOx to client apo-enzymes is indispensable for their catalytic function, proper folding and targeting of specific organelles. PNPOx activity deficiencies due to inborn errors lead to severe neurological pathologies, particularly neonatal epileptic encephalopathy. PNPOx maintains PLP homeostasis through highly regulated mechanisms, including structural alterations throughout the catalytic cycle and allosteric PLP binding, influencing substrate transformation at the active site. Elucidation at the molecular level of the mechanisms underlying PNPOx activity deficiencies is a requirement to develop personalized approaches to treat related disorders. Finally, despite shared features, the few PNPOx enzymes molecularly and functionally studied show species-specific regulatory properties that open the possibility of targeting it in pathogenic organisms. Full article

Pyridoxine (pyr) is a versatile molecule that forms part of the family of B vitamins. It is used to treat and prevent vitamin B₆ deficiency and certain types of metabolic disorders. Moreover, the pyridoxine molecule has been investigated as a suitable ligand toward metal ions. Nevertheless, the study of the magnetic properties of metal complexes containing lanthanide(III) ions and this biomolecule is unexplored. We have synthesized and characterized a novel pyridoxine-based Gd^III complex of formula [Gd^III(pyr)₂(H₂O)₄]Cl₃ · 2 H₂O (1) [pyr = pyridoxine]. 1 crystallizes in the triclinic system and space group Pī. In its crystal packing, cationic [Gd(pyr)₂(H₂O)₄]³⁺ entities are connected through H-bonding interactions involving non-coordinating water molecules and chloride anions. In addition, Hirshfeld surfaces of 1 were calculated to further investigate their intermolecular interactions in the crystal lattice. Our investigation of the magnetic properties of 1, through ac magnetic susceptibility measurements, reveals the occurrence of a slow relaxation in magnetization in this mononuclear Gd^III complex, indicating an unusual single-ion magnet (SIM) behavior for this pseudo-isotropic metal ion at very low temperatures. We also studied the relaxometric properties of 1, as a potential contrast agent for high-field magnetic resonance imaging (MRI), from solutions of 1 prepared in physiological serum (0.0–3.2 mM range) and measured at 3 T on a clinical MRI scanner. The values of relaxivity obtained for 1 are larger than those of some commercial MRI contrast agents based on mononuclear Gd^III systems. Full article

Many inherited metabolic disorders (IMDs), including disorders of amino acid, fatty acid, and carbohydrate metabolism, are treated with a dietary reduction or exclusion of certain macronutrients, putting one at risk of a reduced intake of micronutrients. In this review, we aim to provide available evidence on the most common micronutrient deficits related to specific dietary approaches and on the management of their deficiency, in the meanwhile discussing the main critical points of each nutritional supplementation. The emerging concepts are that a great heterogeneity in clinical practice exists, as well as no univocal evidence on the most common micronutrient abnormalities. In phenylketonuria, for example, micronutrients are recommended to be supplemented through protein substitutes; however, not all formulas are equally supplemented and some of them are not added with micronutrients. Data on pyridoxine and riboflavin status in these patients are particularly scarce. In long-chain fatty acid oxidation disorders, no specific recommendations on micronutrient supplementation are available. Regarding carbohydrate metabolism disorders, the difficult-to-ascertain sugar content in supplementation formulas is still a matter of concern. A ketogenic diet may predispose one to both oligoelement deficits and their overload, and therefore deserves specific formulations. In conclusion, our overview points out the lack of unanimous approaches to micronutrient deficiencies, the need for specific formulations for IMDs, and the necessity of high-quality studies, particularly for some under-investigated deficits. Full article

Introduction and Purpose: Athletes, especially in weight-dependent sports, are at higher risk of developing eating disorders (ED). Relative Energy Deficiency in Sport (RED-S) results from a mismatch between energy intake (EI) and exercise, leading to an athlete triad. Material and Methods: Our study includes ten high-performance athletes who came to the Center for Sports Nutrition and Supplementation because of ED. Nutritional and mental status were evaluated individually (physician’s examination, body composition, eating and supplement habits, blood analysis, accelerometer, and three-day diet diary). Results: Nine female and one male athlete with an average age of 17 years are classified as having anorexia nervosa (5), bulimia nervosa (4), or an eating disorder not otherwise specified (1). Female athletes had an average BMI of 18.4 kg/m² and an F% of 19.7. All athletes had RED-S with an average EI of 1660 kcal/day and an energy expenditure of 2300 kcal/day. Representing different sports (swimming, volleyball, tennis, basketball, jazz ballet, and synchronized swimming), 7/10 athletes stopped training and 5/10 needed hospitalization because of ED exacerbation. In 7/9 athletes, there were <6 menses/12 months. An antidepressive drug (SSRIs) was indicated in six athletes. The average serum iron level was low, at 13.5 micromol/L. Carbohydrates, fat, and proteins were present in EI at 42.8%, 35.4%, and 21.8%. Athletes showed an intake deficit of cholesterol, magnesium, biotin, chrome, iron, fiber, folate, iodine, potassium, vitamins D, E, and K, pantothenic acid, and pyridoxine. Conclusion: Early identification of ED is associated with better outcomes. Educating athletes, sports entourages, and especially parents about healthy eating, pathological eating behaviors, and their consequences is crucial. Full article

The main treatment for pyridoxine-nonresponsive cystathionine-β-synthase deficiency is a strict diet. Most centers prescribe low-protein diets based on gram–protein exchanges, and all protein sources are weighed. The purpose of this study is to investigate the effects of a more liberal methionine (Met)-based diet with relaxed consumption of fruits and vegetables on metabolic outcomes and dietary adherence. Ten patients previously on a low-protein diet based on a gram–protein exchange list were enrolled. The natural protein exchange lists were switched to a “Met portion exchange list”. Foods containing less than 0.005 g methionine per 100 g of the food were accepted as exchange-free foods. The switch to Met portioning had no adverse effects on the control of plasma homocysteine levels in terms of metabolic outcomes. It resulted in a significant reduction in patients’ daily betaine dose. All patients preferred to continue with this modality. In conclusion, methionine-portion-based medical nutrition therapy with relaxed consumption of fruits and vegetables seems to be a good and safe option to achieve good metabolic outcomes and high treatment adherence. Full article

Introduction: Vitamin B6 is a water-soluble vitamin that is naturally present in many foods and is accessible in many dietary supplements. The three natural forms are pyridoxine, pyridoxal, and pyridoxamine. Both vitamin B6 deficiency and high B6 intake have been described as risk factors for developing peripheral neuropathy (PN). The aim of this systematic review is to characterize and comprehensively describe B6-related PN. Method: A systematic, computer-based search was conducted using the PubMed database. Twenty articles were included in this review. Results: Higher vitamin B6 levels, which usually occur following the taking of nutritional supplements, may lead to the development of a predominantly, if not exclusively, sensory neuropathy of the axonal type. After pyridoxine discontinuation, such patients subjectively report improved symptoms. However, although low vitamin B6 levels can be seen in patients suffering from peripheral neuropathy of various etiologies, there is no firm evidence that low B6 levels have a direct causal relationship with PN. Many studies suggest subjective improvement of neuropathy symptoms in patients suffering from PN of various etiologies after receiving B6 supplementation; however, no data about B6 administration as a monotherapy exist, only as part of a combination treatment, usually with other vitamins. Therefore, the potential therapeutic role of B6 cannot be confirmed to date. Supplementation with vitamin B6, even as part of a nutritional multivitamin supplement, has not been proven harmful at permitted daily doses in patients who already suffer from PN. Conclusion: Current scientific evidence supports a neurotoxic role of B6 at high levels. Although some studies suggest that low B6 is also a potential risk factor, further studies in this area are needed. Full article

The number of people living with chronic kidney disease (CKD) is growing as our global population continues to expand. With aging, diabetes, and cardiovascular disease being major harbingers of kidney disease, the number of people diagnosed with diabetic kidney disease (DKD) has grown concurrently. Poor clinical outcomes in DKD could be influenced by an array of factors—inadequate glycemic control, obesity, metabolic acidosis, anemia, cellular senescence, infection and inflammation, cognitive impairment, reduced physical exercise threshold, and, importantly, malnutrition contributing to protein-energy wasting, sarcopenia, and frailty. Amongst the various causes of malnutrition in DKD, the metabolic mechanisms of vitamin B (B1 (Thiamine), B2 (Riboflavin), B3 (Niacin/Nicotinamide), B5 (Pantothenic Acid), B6 (Pyridoxine), B8 (Biotin), B9 (Folate), and B12 (Cobalamin)) deficiency and its clinical impact has garnered greater scientific interest over the past decade. There remains extensive debate on the biochemical intricacies of vitamin B metabolic pathways and how their deficiencies may affect the development of CKD, diabetes, and subsequently DKD, and vice-versa. Our article provides a review of updated evidence on the biochemical and physiological properties of the vitamin B sub-forms in normal states, and how vitamin B deficiency and defects in their metabolic pathways may influence CKD/DKD pathophysiology, and in reverse how CKD/DKD progression may affect vitamin B metabolism. We hope our article increases awareness of vitamin B deficiency in DKD and the complex physiological associations that exist between vitamin B deficiency, diabetes, and CKD. Further research efforts are needed going forward to address the knowledge gaps on this topic. Full article

Background: Vitamin B6-dependent epilepsies include treatable diseases responding to pyridoxine or pyridoxal-5Iphosphate (ALDH7A1 deficiency, PNPO deficiency, PLP binding protein deficiency, hyperprolinemia type II and hypophosphatasia and glycosylphosphatidylinositol anchor synthesis defects). Patients and methods: We conducted a systematic review of published pediatric cases with a confirmed molecular genetic diagnosis of vitamin B6-dependent epilepsy according to PRISMA guidelines. Data on demographic features, seizure semiology, EEG patterns, neuroimaging, treatment, and developmental outcomes were collected. Results: 497 published patients fulfilled the inclusion criteria. Seizure onset manifested at 59.8 ± 291.6 days (67.8% of cases in the first month of life). Clonic, tonic-clonic, and myoclonic seizures accounted for two-thirds of the cases, while epileptic spasms were observed in 7.6%. Burst-suppression/suppression-burst represented the most frequently reported specific EEG pattern (14.4%), mainly in PLPB, ALDH7A1, and PNPO deficiency. Pyridoxine was administered to 312 patients (18.5% intravenously, 76.9% orally, 4.6% not specified), and 180 also received antiseizure medications. Pyridoxine dosage ranged between 1 and 55 mg/kg/die. Complete seizure freedom was achieved in 160 patients, while a significant seizure reduction occurred in 38. PLP, lysine-restricted diet, and arginine supplementation were used in a small proportion of patients with variable efficacy. Global developmental delay was established in 30.5% of a few patients in whom neurocognitive tests were performed. Conclusions: Despite the wide variability, the most frequent hallmarks of the epilepsy phenotype in patients with vitamin B6-dependent seizures include generalized or focal motor seizure semiology and a burst suppression/suppression burst pattern in EEG. Full article

Cysthiatonine beta-synthase (CBS) deficiency (CBSD) is an autosomal recessive rare disorder caused by variations on CBS that leads to impaired conversion of homocysteine (Hcy) to cystathionine. Marked hyperhomocysteinemia is the hallmark of the disease. The administration of pyridoxine, the natural cofactor of CBS, may reduce total plasma Hcy. Patient phenotype is classified on pyridoxine responsivity in two groups: pyridoxine-responsive and non-responsive patients. Ectopia lentis, bone deformities, developmental delay, and thromboembolism are the classic signs and symptoms of the disease. Early diagnosis and treatment impact patients’ natural history. Therapy aims to lower promptly and maintain Hcy concentrations below 100 μmol/L. Depending on the patient’s phenotype, the treatment goals could be obtained by the administration of pyridoxine and/or betaine associated with a methionine-restricted diet. CBSD could be diagnosed in the early days of life by expanded newborn screening (ENS), however, the risk of false negative results is not negligible. In Emilia-Romagna (Italy), during the first 10 years of screening experience, only three cases of CBSD identified have been diagnosed, all in the last two years (incidence 1:118,000 live births). We present the cases and a comprehensive review of the literature to emphasize the role of ENS for early diagnosis of CBSD and its potential pitfalls, reiterating the need for a more effective method to screen for CBSD. Full article

Background: Increasingly, chronic kidney disease (CKD) is becoming an inevitable consequence of obesity, metabolic syndrome, and diabetes. As the disease progresses, and through dialysis, the need for and loss of water-soluble vitamins both increase. This review article looks at the benefits and possible risks of supplementing these vitamins with the treatment of CKD. Methods: Data in the PubMed and Embase databases were analyzed. The keywords “chronic kidney disease”, in various combinations, are associated with thiamin, riboflavin, pyridoxine, pantothenic acid, folates, niacin, cobalamin, and vitamin C. This review focuses on the possible use of water-soluble vitamin supplementation to improve pharmacological responses and the overall clinical condition of patients. Results: The mechanism of supportive supplementation is based on reducing oxidative stress, covering the increased demand and losses resulting from the treatment method. In the initial period of failure (G2-G3a), it does not require intervention, but later, especially in the case of inadequate nutrition, the inclusion of supplementation with folate and cobalamin may bring benefits. Such supplementation seems to be a necessity in patients with stage G4 or G5 (uremia). Conversely, the inclusion of additional B6 supplementation to reduce CV risk may be considered. At stage 3b and beyond (stages 4–5), the inclusion of niacin at a dose of 400–1000 mg, depending on the patient’s tolerance, is required to lower the phosphate level. The inclusion of supplementation with thiamine and other water-soluble vitamins, especially in peritoneal dialysis and hemodialysis patients, is necessary for reducing dialysis losses. Allowing hemodialysis patients to take low doses of oral vitamin C effectively reduces erythropoietin dose requirements and improves anemia in functional iron-deficient patients. However, it should be considered that doses of B vitamins that are several times higher than the recommended dietary allowance of consumption may exacerbate left ventricular diastolic dysfunction in CKD patients. Conclusions: Taking into account the research conducted so far, it seems that the use of vitamin supplementation in CKD patients may have a positive impact on the treatment process and maintaining a disease-free condition. Full article

Pyridoxine-dependent epilepsy (PDE) is a rare autosomal recessive developmental and epileptic encephalopathy caused by pathogenic variants in the ALDH7A1 gene (PDE-ALDH7A1), which mainly has its onset in neonates and infants. Early diagnosis and treatment are crucial to prevent severe neurological sequelae or death. Sensitive, specific, and stable biomarkers for diagnostic evaluations and follow-up examinations are essential to optimize outcomes. However, most of the known biomarkers for PDE lack these criteria. Additionally, there is little discussion regarding the interdependence of biomarkers in the PDE-ALDH7A1 metabolite profile. Therefore, the aim of this study was to understand the underlying mechanisms in PDE-ALDH7A1 and to discover new biomarkers in the plasma of patients using global metabolomics. Plasma samples from 9 patients with genetically confirmed PDE-ALDH7A1 and 22 carefully selected control individuals were analyzed by ultra high performance liquid chromatography–high-resolution mass spectrometry (UHPLC-HRMS). Two novel and reliable pyridoxine-independent diagnostic markers, 6-hydroxy-2-aminocaproic acid (HACA) and an isomer of C₉H₁₁NO₄, were identified. Furthermore, a possible reaction mechanism is proposed for HACA. This study demonstrates the capability of global metabolomics in disease screening to detect established and novel biomarkers. Full article