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1.
Am J Med Sci ; 361(6): 791-794, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33958192

RESUMO

Pyridoxine is an important co-factor for many biochemical reactions in cellular metabolism related to the synthesis and catabolism of amino acids, fatty acids, neurotransmitters. Deficiency of pyridoxine results in impaired transcellular signaling between neurons and presents with muscular convulsions, hyperirritability, and peripheral neuropathy. Deficiency of pyridoxine is usually found in association with other vitamin B deficiencies such as folate (vitamin B9) and cobalamin (vitamin B12). Isolated pyridoxine deficiency is extremely rare. We present the case of a 59-year old female with type 2 diabetes who complained of painful muscle spasms. Her muscle spasms involved in both feet, which have spread proximally to her legs. She also experienced intermittent muscle spasms in her left arm, which is not alleviated by baclofen, cyclobenzaprine. Her plasma pyridoxal 5-phosphate confirmed pyridoxine deficiency. Vitamins B1, B3, B12, and folate were within normal limits. The patient received standard-dose intramuscular pyridoxine injections for three weeks followed by oral supplements for 3 months and her symptoms resolved. This case illustrates the rare instance of isolated pyridoxine deficiency in type 2 diabetes patient manifesting as myoclonic muscle spasms involving the legs and arms in the absence of objective polyneuropathy. Pyridoxine level should, therefore, be assessed in patients with type 2 diabetes, including newly diagnosed patients.


Assuntos
Diabetes Mellitus Tipo 2/sangue , Piridoxina/sangue , Espasmo/sangue , Deficiência de Vitamina B 6/sangue , Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diagnóstico Diferencial , Feminino , Humanos , Pessoa de Meia-Idade , Piridoxina/administração & dosagem , Piridoxina/deficiência , Espasmo/diagnóstico , Espasmo/tratamento farmacológico , Deficiência de Vitamina B 6/diagnóstico , Deficiência de Vitamina B 6/tratamento farmacológico
3.
Nurs Clin North Am ; 56(1): 23-32, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33549283

RESUMO

Vitamin B6, a cofactor in many biochemical reactions in the cells of living organisms, is an essential coenzyme for various catabolic and anabolic processes. Although vitamin B6 deficiency in young healthy women with a balanced diet is thought to be unusual, it can be seen with certain medications, health conditions, and dietary deficits, as well as aging. Vitamin B6 deficiency is associated with a variety of ill health effects, and correction of deficiency is considered beneficial. Women particularly are affected by unique health issues that are part of the array of disorders potentially alleviated through vitamin B6 supplementation.


Assuntos
Necessidades Nutricionais , Deficiência de Vitamina B 6/prevenção & controle , Vitamina B 6/uso terapêutico , Saúde da Mulher , Envelhecimento , Feminino , Humanos , Deficiência de Vitamina B 6/tratamento farmacológico
4.
Int J Hematol ; 110(5): 543-549, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31407257

RESUMO

Vitamin B6 (VB6) deficiency contributes to oncogenesis and tumor progression in certain cancers, and is prevalent in cancer patients in general. VB6 is also an essential element of heme synthesis, and deficiency can lead to anemia. Primary myelofibrosis (PMF) and secondary myelofibrosis (sMF) are myeloproliferative neoplasms often presenting with anemia along with other cytopenias. We performed a prospective study to determine whether PMF and sMF patients suffer from VB6 deficiency, and whether VB6-deficient patients show improvement of anemias with VB6 supplementation. Twelve PMF patients and 11 sMF patients were analyzed. A total of 16 of 23 patients (69.6%) were found to have VB6 deficiency, but VB6 supplementation with pyridoxal phosphate hydrate did not elevate hemoglobin levels in deficient patients. None of the patients presented with vitamin B12, iron, or copper deficiencies. Four patients showed serum folate levels below the lower limit of normal and eight patients showed serum zinc levels below the lower limit of normal; however, these deficiencies were marginal and unlikely to contribute to anemia. Compared to VB6-sufficient patients, VB6-deficient patients showed significantly lower serum folate levels and higher serum copper levels. Studies elucidating the relationship of VB6 deficiency and etiology of PMF/sMF are warranted.


Assuntos
Mielofibrose Primária/sangue , Deficiência de Vitamina B 6/sangue , Adulto , Anemia , Cobre/sangue , Feminino , Ácido Fólico/sangue , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Mielofibrose Primária/etiologia , Estudos Prospectivos , Fosfato de Piridoxal/uso terapêutico , Deficiência de Vitamina B 6/tratamento farmacológico
5.
BMJ Case Rep ; 12(8)2019 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-31377720

RESUMO

A 39-year-old woman with a history of Roux-en-Y gastric bypass (RYGB) surgery and alcohol use presented with a confluent erythematous rash involving the perineum spreading outward to the abdomen, thighs and lower back. She had angular cheilitis and glossitis. The rash was painful and blistering in scattered areas. She was hypotensive and appeared to be in septic or hypovolemic shock at presentation. Serum levels of zinc and vitamin B6 were critically low and biopsy of her rash returned suggestive of a nutritional deficiency as its source. The rash slowly improved over the following 2 weeks with oral zinc and vitamin B6 replacement. The body rash resembled that of infants born with inherited defects in zinc transporters, referred to as acrodermatitis enteropathica (AE). This case may represent an acquired case of AE in the setting of prior RYGB.


Assuntos
Deficiência de Vitamina B 6/diagnóstico , Vitamina B 6/administração & dosagem , Zinco/administração & dosagem , Zinco/deficiência , Administração Oral , Adulto , Biópsia , Queilite/etiologia , Exantema/etiologia , Derivação Gástrica/efeitos adversos , Humanos , Resultado do Tratamento , Vitamina B 6/uso terapêutico , Deficiência de Vitamina B 6/tratamento farmacológico
6.
Rev Med Interne ; 40(7): 462-465, 2019 Jul.
Artigo em Francês | MEDLINE | ID: mdl-31133329

RESUMO

INTRODUCTION: Sideroblastic anemia is a rare cause of microcytic anemia, which is characterized by ring sideroblasts on bone marrow aspirate. This anemia can be congenital or acquired. CASE REPORT: We report the case of an alcoholic 49-year-old man who presented with a severe microcytic sideroblastic anemia related to pyridoxine (B6 vitamin) deficiency. Acid folic deficiency was associated. The blood count normalized within one month after vitamin supplementation. CONCLUSION: Pyridoxine deficiency must be sought in sideroblastic anemia in patients at risk.


Assuntos
Anemia Sideroblástica/tratamento farmacológico , Deficiência de Vitamina B 6/tratamento farmacológico , Vitamina B 6/uso terapêutico , Alcoolismo/complicações , Alcoolismo/diagnóstico , Alcoolismo/tratamento farmacológico , Anemia Sideroblástica/complicações , Anemia Sideroblástica/diagnóstico , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento , Deficiência de Vitamina B 6/complicações , Deficiência de Vitamina B 6/diagnóstico
7.
Yakugaku Zasshi ; 139(1): 1-6, 2019.
Artigo em Japonês | MEDLINE | ID: mdl-30606915

RESUMO

Overconsumption of Ginkgo biloba seeds induces food poisoning characterized by tonic-clonic convulsions and vomiting. The primary toxic component, 4'-O-methylpyridoxine (MPN), was purified from the seeds in 1985. This review includes the following aspects of ginkgo seed poisoning: 1) toxicity related to the content of MPN and MPN glucoside in G. biloba seeds; 2) the effect of MPN on vitamin B6 analogs, including an increase in pyridoxal and pyridoxic acid and decrease in pyridoxal-5'-phosphate plasma concentrations; 3) case reports of ginkgo seed poisoning in Asia, North America, and Europe, and their effective treatment via vitamin B6 administration. Considering the increase in the use of G. biloba seeds, it is essential to raise global awareness of their potential toxicity.


Assuntos
Doenças Transmitidas por Alimentos/etiologia , Ginkgo biloba/química , Ginkgo biloba/intoxicação , Piridoxina/análogos & derivados , Deficiência de Vitamina B 6/etiologia , Humanos , Fosfato de Piridoxal/sangue , Ácido Piridóxico/sangue , Piridoxina/isolamento & purificação , Piridoxina/toxicidade , Vitamina B 6/administração & dosagem , Vitamina B 6/metabolismo , Deficiência de Vitamina B 6/tratamento farmacológico
8.
Arch. argent. pediatr ; 116(3): 445-450, jun. 2018. ilus
Artigo em Espanhol | LILACS, BINACIS | ID: biblio-950024

RESUMO

La hipertensión endocraneana idiopàtica se asocia infrecuentemente con la hipovitaminosis A y D. Se presenta el caso de una paciente femenina de 8 años con visión borrosa de 24 horas y papiledema bilateral. Resonancia magnética nuclear normal. Presión de apertura de líquido cefalorraquídeo: 260 mm^O. Presentó déficit de vitamina A y D, e inició un tratamiento sustitutivo. El segundo caso corresponde a un paciente masculino de 12 años con fiebre y odinofagia de 3 días. Con antecedente de glomerulonefritis y sobrepeso. Presentaba edema bipalpebral y papiledema. Tomografia axial computada de la órbita: aumento de líquido en la vaina de ambos nervios ópticos. Resonancia magnética nuclear: aracnoidocele intraselar. Presión de apertura de líquido cefalorraquídeo: 400 mm^O. Presentó déficit de vitamina D y B6, e inició el tratamiento sustitutivo. La elevación de la presión intracraneal desencadena mecanismos de compensación que, al fallar, pueden comprometer la vida o provocar graves discapacidades neurológicas. Reconocer la causa para un enfoque terapéutico preciso es clave para disminuir la morbimortalidad asociada a esta patología.


Idiopathic endocranial hypertension is infrequently associated with hypovitaminosis A and D. The case of an 8-year-old female with 24-hour blurred vision and bilateral papilledema is presented. Nuclear magnetic resonance was normal. Opening pressure of cerebrospinal fluid: 260 mm^O. She presented vitamin A and D deficiency and started replacement therapy. The second case corresponds to a 12-year-old male with fever and odynophagia of 3 days. History of glomerulonephritis and overweight. He had bipalpebral edema and papilledema. Computed tomography scan of the orbit: increase of fluid in the sheath of both optic nerves. Nuclear magnetic resonance: intrasellar arachnoidocele. Opening pressure of cerebrospinal fluid: 400 mmH2O. He presented vitamin D and B6 deficiency and started replacement treatment. The elevation of intracranial pressure triggers compensation mechanisms that, when they fail, can compromise life or cause serious neurological disabilities. Recognizing the cause for an accurate therapeutic approach is key to reduce the morbidity and mortality associated with this pathology.


Assuntos
Humanos , Masculino , Feminino , Criança , Deficiência de Vitamina B 6/complicações , Deficiência de Vitamina A/complicações , Deficiência de Vitamina D/complicações , Pseudotumor Cerebral/diagnóstico , Deficiência de Vitamina B 6/tratamento farmacológico , Transtornos da Visão/etiologia , Vitamina A/administração & dosagem , Deficiência de Vitamina A/tratamento farmacológico , Vitamina D/administração & dosagem , Deficiência de Vitamina D/tratamento farmacológico , Pseudotumor Cerebral/etiologia , Imageamento por Ressonância Magnética , Tomografia Computadorizada por Raios X/métodos , Papiledema/etiologia , Hipertensão Intracraniana/diagnóstico , Hipertensão Intracraniana/etiologia , Vitamina B 6/administração & dosagem
9.
Arch Argent Pediatr ; 116(3): e445-e450, 2018 06 01.
Artigo em Espanhol | MEDLINE | ID: mdl-29756721

RESUMO

Idiopathic endocranial hypertension is infrequently associated with hypovitaminosis A and D. The case of an 8-year-old female with 24-hour blurred vision and bilateral papilledema is presented. Nuclear magnetic resonance was normal. Opening pressure of cerebrospinal fluid: 260 mmH2O. She presented vitamin A and D deficiency and started replacement therapy. The second case corresponds to a 12-year-old male with fever and odynophagia of 3 days. History of glomerulonephritis and overweight. He had bipalpebral edema and papilledema. Computed tomography scan of the orbit: increase of fluid in the sheath of both optic nerves. Nuclear magnetic resonance: intrasellar arachnoidocele. Opening pressure of cerebrospinal fluid: 400 mmH2O. He presented vitamin D and B6 deficiency and started replacement treatment. The elevation of intracranial pressure triggers compensation mechanisms that, when they fail, can compromise life or cause serious neurological disabilities. Recognizing the cause for an accurate therapeutic approach is key to reduce the morbidity and mortality associated with this pathology.


La hipertensión endocraneana idiopática se asocia infrecuentemente con la hipovitaminosis A y D. Se presenta el caso de una paciente femenina de 8 años con visión borrosa de 24 horas y papiledema bilateral. Resonancia magnética nuclear normal. Presión de apertura de líquido cefalorraquídeo: 260 mmH2O. Presentó déficit de vitamina A y D, e inició un tratamiento sustitutivo. El segundo caso corresponde a un paciente masculino de 12 años con fiebre y odinofagia de 3 días. Con antecedente de glomerulonefritis y sobrepeso. Presentaba edema bipalpebral y papiledema. Tomografía axial computada de la órbita: aumento de líquido en la vaina de ambos nervios ópticos. Resonancia magnética nuclear: aracnoidocele intraselar. Presión de apertura de líquido cefalorraquídeo: 400 mmH2O. Presentó déficit de vitamina D y B6, e inició el tratamiento sustitutivo. La elevación de la presión intracraneal desencadena mecanismos de compensación que, al fallar, pueden comprometer la vida o provocar graves discapacidades neurológicas. Reconocer la causa para un enfoque terapéutico preciso es clave para disminuir la morbimortalidad asociada a esta patología.


Assuntos
Pseudotumor Cerebral/diagnóstico , Deficiência de Vitamina A/complicações , Deficiência de Vitamina B 6/complicações , Deficiência de Vitamina D/complicações , Criança , Feminino , Humanos , Hipertensão Intracraniana/diagnóstico , Hipertensão Intracraniana/etiologia , Imageamento por Ressonância Magnética , Masculino , Papiledema/etiologia , Pseudotumor Cerebral/etiologia , Tomografia Computadorizada por Raios X/métodos , Transtornos da Visão/etiologia , Vitamina A/administração & dosagem , Deficiência de Vitamina A/tratamento farmacológico , Vitamina B 6/administração & dosagem , Deficiência de Vitamina B 6/tratamento farmacológico , Vitamina D/administração & dosagem , Deficiência de Vitamina D/tratamento farmacológico
10.
Pediatrics ; 141(Suppl 5): S430-S433, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29610166

RESUMO

Pyridox(am)ine-5-phosphate oxidase deficiency is an inborn error of vitamin B6 metabolism that is characterized by neonatal seizures, requiring lifelong therapy with pyridoxal-5-phosphate. We present the first case of a patient with pyridox(am)ine-5-phosphate oxidase deficiency and mild hemophilia A, whose bleeding symptoms were exacerbated by the vitamin B6 therapy essential for his epileptic disorder. This report expands the spectrum of known vitamin B6 toxicity and demonstrates a need for vigilance in monitoring for bleeding symptoms in patients requiring pyridoxine or pyridoxal-5-phosphate supplementation.


Assuntos
Hemofilia A/complicações , Hemorragia/etiologia , Fosfato de Piridoxal/deficiência , Convulsões/tratamento farmacológico , Deficiência de Vitamina B 6/tratamento farmacológico , Vitamina B 6/efeitos adversos , Vitaminas/efeitos adversos , Criança , Progressão da Doença , Humanos , Masculino , Convulsões/etiologia , Deficiência de Vitamina B 6/complicações
11.
Mol Nutr Food Res ; 60(7): 1615-24, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-26935476

RESUMO

SCOPE: Vitamin B6 plays crucial roles on brain development and its maternal deficiency impacts the gamma-aminobutyric acid (GABA)ergic, serotonergic, glutamatergic, and dopaminergic systems in offspring. However, the molecular mechanisms underlying these neurological changes are not well understood. Thus, we aimed at evaluating which components of those neurotransmitter metabolism and signaling pathways can be modulated by maternal vitamin B6 -deficient or B6 -supplementated diets in the hippocampus of rat dams and their offspring. METHODS AND RESULTS: Female Wistar rats were fed three different diets: control (6 mg vitamin B6 /kg), supplemented (30 mg vitamin B6 /kg) or deficient diet (0 mg vitamin B6 /kg), from 4 weeks before pregnancy through lactation. Newborn pups (10 days old) from rat dams fed vitamin B6 -deficient diet presented hyperhomocysteinemia and had a significant increase in mRNA levels of glutamate decarboxylase 1 (Gad1), fibroblast growth factor 2 (Fgf2), and glutamate-ammonia ligase (Glul), while glutaminase (Gls) and tryptophan hydroxylase 1 (Tph1) mRNAs were downregulated. Vitamin B6 supplementation or deficiency did not change hippocampal global DNA methylation. CONCLUSION: A maternal vitamin B6 -deficient diet affects the expression of genes related to GABA, glutamate, and serotonin metabolisms in offspring by regulating Gad1, Glul, Gls, and Tph1 mRNA expression.


Assuntos
Hipocampo/efeitos dos fármacos , Deficiência de Vitamina B 6/sangue , Vitamina B 6/administração & dosagem , Vitamina B 6/sangue , Animais , Animais Recém-Nascidos , Metilação de DNA , Suplementos Nutricionais , Feminino , Fator 2 de Crescimento de Fibroblastos/genética , Fator 2 de Crescimento de Fibroblastos/metabolismo , Regulação da Expressão Gênica , Glutamato Descarboxilase/genética , Glutamato Descarboxilase/metabolismo , Glutamato-Amônia Ligase/genética , Glutamato-Amônia Ligase/metabolismo , Ácido Glutâmico/metabolismo , Glutaminase/genética , Glutaminase/metabolismo , Hipocampo/metabolismo , Homocisteína/sangue , Ratos , Ratos Wistar , Serotonina/metabolismo , Triptofano Hidroxilase/genética , Triptofano Hidroxilase/metabolismo , Deficiência de Vitamina B 6/tratamento farmacológico , Ácido gama-Aminobutírico/metabolismo
12.
J Clin Neuromuscul Dis ; 16(1): 25-31, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25137514

RESUMO

Pyridoxine deficiency and excess have been implicated as a cause for peripheral neuropathy. As a result, unrelated neuropathies are often treated with pyridoxine based on questionable evidence. However, neurological practitioners frequently discourage patients from taking pyridoxine in excess of 50 mg/d given concerns around the development of a toxic sensory neuronopathy. There is no systematic review to support either of the 2 practices. To address this gap in knowledge, we reviewed the available literature on neuropathy attributed to pyridoxine deficiency and excess. Based on the current limited data, it can be concluded that very low doses of daily pyridoxine are required to prevent peripheral neuropathy. There is inadequate evidence to support routine pyridoxine supplementation in patients with disorders of peripheral nervous system. Supplementation with pyridoxine at doses greater than 50 mg/d for extended duration may be harmful and should be discouraged.


Assuntos
Medicina Baseada em Evidências , Doenças do Sistema Nervoso Periférico/etiologia , Piridoxina/efeitos adversos , Deficiência de Vitamina B 6/complicações , Ensaios Clínicos como Assunto , Feminino , Humanos , Masculino , PubMed/estatística & dados numéricos , Deficiência de Vitamina B 6/tratamento farmacológico
13.
Int J Tuberc Lung Dis ; 18(1): 27-33, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24365548

RESUMO

SETTING: Human immunodeficiency virus (HIV) infection and treatments for HIV infection and tuberculosis (TB) are associated with the risk of developing sensory polyneuropathy (SPN). Vitamin B6 and genetically determined slow isoniazid (INH) acetylation are believed to play key roles in the development of SPN in a TB treatment setting. OBJECTIVE: To investigate slow acetylation and risk factors for SPN in HIV-infected patients receiving TB treatment, and establish vitamin B6 status and its association with SPN. METHODS: HIV-infected in-patients were prospectively assessed after initiating TB treatment and vitamin B6 supplementation, and monthly during hospitalisation. SPN was defined as ≥1 symptom plus ≥1 sign. NAT2 genotyping predicted acetylation status, and plasma high performance liquid chromatography estimated vitamin B6 status. A survival analysis estimated hazard ratios (HRs) for SPN during TB treatment. RESULTS: Of 116 participants, 56% had SPN at study entry. Participants developed SPN at a rate of 26/100 person-months (95%CI 18-35) during TB treatment, which was independently associated with slow acetylation (HR 2.5; 95%CI 1.1-5.9), as well as black race, previous TB and extra-pulmonary/disseminated TB. Vitamin B6 status was normal, irrespective of SPN. CONCLUSIONS: Risk factors for SPN suggest a multi-factorial pathogenesis related to INH and other potential nervous system insults. SPN developed despite normal vitamin B6 status, suggesting other mechanisms of injury.


Assuntos
Antituberculosos/efeitos adversos , Infecções por HIV/complicações , Polineuropatias/induzido quimicamente , Células Receptoras Sensoriais , Tuberculose Pulmonar/tratamento farmacológico , Acetilação , Adulto , Arilamina N-Acetiltransferase/genética , Arilamina N-Acetiltransferase/metabolismo , Suplementos Nutricionais , Feminino , Genótipo , Infecções por HIV/diagnóstico , Infecções por HIV/mortalidade , Humanos , Estudos Longitudinais , Masculino , Fenótipo , Polineuropatias/diagnóstico , Polineuropatias/fisiopatologia , Estudos Prospectivos , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento , Tuberculose Pulmonar/complicações , Tuberculose Pulmonar/diagnóstico , Tuberculose Pulmonar/microbiologia , Tuberculose Pulmonar/mortalidade , Vitamina B 6/sangue , Vitamina B 6/uso terapêutico , Deficiência de Vitamina B 6/sangue , Deficiência de Vitamina B 6/complicações , Deficiência de Vitamina B 6/diagnóstico , Deficiência de Vitamina B 6/tratamento farmacológico , Vitaminas/uso terapêutico
14.
Pak J Pharm Sci ; 26(5): 1057-69, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24035968

RESUMO

Vitamin B6 (pyridoxine) is closely associated with the functions of the nervous, immune and endocrine systems. It also participates in the metabolic processes of proteins, lipids and carbohydrates. Pyridoxine deficiency may result in neurological disorders including convulsions and epileptic encephalopathy and may lead to infant abnormalities. The Intravenous administration of pyridoxine to patients results in a dramatic cessation of seizures. A number of analytical methods were developed for the determination of pyridoxine in different dosage forms, food materials and biological fluids. These include UV spectrometric, spectrofluorimetric, mass spectrometric, thin-layer and high-performance liquid chromatographic, electrophoretic, electrochemical and enzymatic methods. Most of these methods are capable of determining pyridoxine in the presence of other vitamins and complex systems in µg quantities. The development and applications of these methods in pharmaceutical and clinical analysis mostly during the last decade have been reviewed.


Assuntos
Técnicas de Química Analítica , Piridoxina/análise , Deficiência de Vitamina B 6/sangue , Animais , Biomarcadores/sangue , Humanos , Piridoxina/sangue , Piridoxina/deficiência , Piridoxina/uso terapêutico , Deficiência de Vitamina B 6/diagnóstico , Deficiência de Vitamina B 6/tratamento farmacológico
15.
Handb Clin Neurol ; 113: 1811-7, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23622403

RESUMO

To date we know of four inborn errors of autosomal recessive inheritance that lead to vitamin B6-dependent seizures. Among these, pyridoxine-dependent seizures due to antiquitin deficiency is by far the most common, although exact incidence data are lacking. In PNPO deficiency, samples have to be collected prior to treatment, while PDE, hyperprolinemia type II and congenital HPP can be diagnosed while on vitamin B6 supplementation. A vitamin B6 withdrawal for diagnostic purposes is nowadays only indicated in patients with a clear vitamin B6 response but normal biochemical work-up. In the presence of therapy-resistant neonatal seizures, early consideration of a vitamin B6 trial over 3 consecutive days is crucial in order to prevent irreversible brain damage. While PLP would be effective in all four disorders, pyridoxine fails to treat seizures in PNPO deficiency. As PLP is unlicensed within Europe and North America, pyridoxine is widely used as the first line drug, but if it is ineffective it should be followed by a trial with PLP, especially in neonates. As severe apnea has been described in responders, resuscitation equipment should be at hand during a first pyridoxine/PLP administration. Patients and parents have to be informed about the lifelong dependency and recurrence risks in forthcoming pregnancies.


Assuntos
Encefalopatias Metabólicas/diagnóstico , Epilepsia/diagnóstico , Hipóxia-Isquemia Encefálica/diagnóstico , Piridoxaminafosfato Oxidase/deficiência , Convulsões/diagnóstico , Deficiência de Vitamina B 6/diagnóstico , Criança , Epilepsia/etiologia , Humanos , Piridoxina/deficiência , Piridoxina/uso terapêutico , Deficiência de Vitamina B 6/complicações , Deficiência de Vitamina B 6/tratamento farmacológico
16.
World J Gastroenterol ; 19(7): 1005-10, 2013 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-23467420

RESUMO

Colorectal cancer remains the third most common cancer in both women and men worldwide. Identifying modifiable dietary factors is crucial in developing primary prevention strategies. Vitamin B6 is involved in more than 100 coenzyme reactions, and may influence colorectal cancer risk in multiple ways including through its role in one-carbon metabolism related DNA synthesis and methylation and by reducing inflammation, cell proliferation, and oxidative stress. Observational studies of dietary or dietary plus supplementary intake of vitamin B6 and colorectal cancer risk have been inconsistent with most studies reporting nonsignificant positive or inverse associations. However, published studies of plasma pyridoxal 5'-phosphate (the active form of vitamin B6) levels consistently support an approximately 30%-50% reduction in risk of colorectal cancer comparing high with low concentrations. The reasons for the discrepancy in the results between dietary-based and plasma-based studies remain unresolved. Other unresolved questions include the effects of vitamin B6 intake in early life (i.e., childhood or adolescence) and of suboptimal vitamin B6 status on colorectal cancer risk, whether the associations with vitamin B6 differ across molecular subtypes of colorectal cancer, and whether the vitamin B6-colorectal cancer association is modified by genetic variants of one-carbon metabolism.


Assuntos
Neoplasias Colorretais/prevenção & controle , Suplementos Nutricionais , Vitamina B 6/administração & dosagem , Neoplasias Colorretais/epidemiologia , Humanos , Prognóstico , Medição de Risco , Fatores de Risco , Fatores de Tempo , Deficiência de Vitamina B 6/tratamento farmacológico , Deficiência de Vitamina B 6/epidemiologia
17.
Clin Chem Lab Med ; 51(3): 535-43, 2013 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-23314545

RESUMO

Although vitamin B6 and its metabolite, pyridoxal 5'-phosphate (PLP), have been shown to exert beneficial effects in ischemic heart disease, the mechanisms of their action are not fully understood. Some studies have shown that ventricular arrhythmias and mortality upon the occlusion of coronary artery were attenuated by pretreatment of animals with PLP. Furthermore, ischemia-reperfusion-induced abnormalities in cardiac performance and defects in sarcoplasmic reticular Ca2+-transport activities were decreased by PLP. The increase in cardiac contractile activity of isolated heart by ATP was reduced by PLP, unlike propranolol, whereas that by isoproterenol was not depressed by PLP. ATP-induced increase in [Ca2+]i, unlike KCl-induced increase in [Ca2+]i in cardiomyocytes was depressed by PLP. Both high- and low-affinity sites for ATP binding in sarcolemmal membranes were also decreased by PLP. These observations support the view that PLP may produce cardioprotective effects in ischemic heart disease by attenuating the occurrence of intracellular Ca2+ overload due to the blockade of purinergic receptors.


Assuntos
Isquemia Miocárdica/tratamento farmacológico , Fosfato de Piridoxal/uso terapêutico , Vitamina B 6/uso terapêutico , Animais , Cardiotônicos/metabolismo , Cardiotônicos/farmacologia , Cardiotônicos/uso terapêutico , Coração/efeitos dos fármacos , Coração/fisiologia , Isquemia Miocárdica/metabolismo , Isquemia Miocárdica/patologia , Fosfato de Piridoxal/metabolismo , Fosfato de Piridoxal/farmacologia , Traumatismo por Reperfusão/tratamento farmacológico , Traumatismo por Reperfusão/metabolismo , Traumatismo por Reperfusão/patologia , Vitamina B 6/metabolismo , Vitamina B 6/farmacologia , Deficiência de Vitamina B 6/tratamento farmacológico , Deficiência de Vitamina B 6/metabolismo , Deficiência de Vitamina B 6/patologia
18.
J Neural Transm (Vienna) ; 120(2): 315-8, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22798026

RESUMO

Levodopa/carbidopa intestinal gel (LCIG) infusion for the treatment of advanced Parkinson's disease (PD) has been suspected to provoke polyneuropathy in conjunction with vitamin B6, B12 and folate deficiency and elevated homocysteine levels. We describe a PD patient under LCIG therapy developing refractory epileptic seizures obviously promoted by vitamin B6 deficiency.


Assuntos
Carbidopa/efeitos adversos , Levodopa/efeitos adversos , Doença de Parkinson/tratamento farmacológico , Convulsões/induzido quimicamente , Deficiência de Vitamina B 6/induzido quimicamente , Idoso , Carbidopa/uso terapêutico , Combinação de Medicamentos , Feminino , Humanos , Levodopa/uso terapêutico , Convulsões/tratamento farmacológico , Resultado do Tratamento , Vitamina B 6/uso terapêutico , Deficiência de Vitamina B 6/tratamento farmacológico
19.
Ann Nutr Metab ; 61(3): 236-8, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23183295

RESUMO

In the 1930s, Rudolf Peters showed that young rats kept on a semi-synthetic diet with added thiamin and riboflavin but no other supplement developed 'rat acrodynia', a condition characterized by severe cutaneous lesions. In 1934, Paul György showed that the factor which cured 'rat acrodynia' was vitamin B(6). Other studies soon showed that vitamin B(6) deficiency produced convulsions in rats, pigs, and dogs, and a microcytic anemia in certain animals. Samuel Lepkovsky isolated and crystallized vitamin B(6) in 1938. The following year, Leslie Harris and Karl Folkers, and Richard Kuhn and his associates independently showed that vitamin B(6) was a pyridine derivative, 3-hydroxy-4,5-dihydroxy-methyl-2-methyl-pyridine. György proposed the term pyridoxine for this derivative. Esmond Snell developed a microbiological growth assay in 1942 that led to the characterization of pyridoxamine, the animated product of pyridoxine, and pyridoxal, the formyl derivative of pyridoxine. Further studies showed that pyridoxal, pyridoxamine, and pyridoxine have largely equal activity in animals and owe their vitamin activity to the ability of the organism to convert them into the enzymatically active form pyridoxal-5-phosphate. Pyridoxal-5-phosphate plays a role in a wide variety of enzyme systems, especially in the metabolic utilization and transformation of amino acids.


Assuntos
Vitamina B 6/química , Vitamina B 6/história , Vitamina B 6/isolamento & purificação , Vitamina B 6/farmacologia , Animais , Cães , História do Século XX , Fosfato de Piridoxal/metabolismo , Piridoxamina/metabolismo , Piridoxina/metabolismo , Ratos , Suínos , Deficiência de Vitamina B 6/tratamento farmacológico , Deficiência de Vitamina B 6/fisiopatologia , Vitaminas/metabolismo
20.
Int J Gynaecol Obstet ; 116(3): 206-10, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22189065

RESUMO

OBJECTIVE: To determine whether supplementation with vitamin B(6) improves nausea and/or vomiting in pregnancy. METHODS: This experimental study was conducted with 60 pregnant women experiencing nausea and/or vomiting prior to the 12th gestational week. Of these women, 30 were treated daily with 10mg and the remaining 30 with 1.28 mg of pyridoxine hydrochloride for 2 weeks. The primary outcome was the Pregnancy-Unique Quantification of Emesis and Nausea (PUQE) score in each group at the end of treatment. RESULTS: The women experiencing nausea and/or vomiting in pregnancy had significantly lower levels of circulating vitamin B(6) (P=0.007) compared with those without this symptom. Vitamin B(6) supplementation significantly increased plasma vitamin B(6) concentration (P<0.05 in both groups). There were no significant differences in PUQE score or in plasma concentration levels of protein, dopamine, serotonin, unconjugated estriol, and ghrelin after supplementation between the 2 groups at baseline, but there was a significantly lesser decrease in PUQE score and a greater increase in vitamin B(6) level and vitamin B(6) concentration to plasma protein concentration ratios in group 1 than in group 2 after supplementation (P<0.05 for all). CONCLUSION: Although the high-supplementation group had a greater decrease in PUQE score in comparison to the low-supplementation group, the difference is unlikely to affect the severity of symptoms.


Assuntos
Êmese Gravídica/tratamento farmacológico , Piridoxina/uso terapêutico , Deficiência de Vitamina B 6/tratamento farmacológico , Complexo Vitamínico B/uso terapêutico , Adulto , Biomarcadores/sangue , Relação Dose-Resposta a Droga , Esquema de Medicação , Feminino , Humanos , Êmese Gravídica/sangue , Êmese Gravídica/etiologia , Gravidez , Resultado do Tratamento , Vitamina B 6/sangue , Deficiência de Vitamina B 6/sangue , Deficiência de Vitamina B 6/complicações
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