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1.
Am J Clin Nutr ; 107(5): 725-733, 2018 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-29722846

RESUMO

Background: Vitamin D deficiency is common in children with severe acute malnutrition, in whom it is associated with severe wasting. Ready-to-use therapeutic food (the standard treatment) contains modest amounts of vitamin D that do not reliably correct deficiency. Objective: The aim of this study was to determine whether high-dose oral vitamin D3 enhances weight gain and development in children with uncomplicated severe acute malnutrition. Design: We conducted a randomized placebo-controlled trial of high-dose vitamin D3 supplementation in children aged 6-58 mo with uncomplicated severe acute malnutrition in Pakistan. Participants were randomly assigned to receive 2 oral doses of 200,000 IU vitamin D3 or placebo at 2 and 4 wk after starting ready-to-use therapeutic food. The primary outcome was the proportion of participants gaining >15% of baseline weight at 8 wk after starting ready-to-use therapeutic food (the end of the study). Secondary outcomes were mean weight-for-height or -length z score and the proportion of participants with delayed development at the end of the study (assessed with the Denver Development Screening Tool II), adjusted for baseline values. Results: Of the 194 randomly assigned children who started the study, 185 completed the follow-up and were included in the analysis (93 assigned to intervention, 92 to control). High-dose vitamin D3 did not influence the proportion of children gaining >15% of baseline weight at the end of the study (RR: 1.04; 95% CI: 0.94,1.15, P = 0.47), but it did increase the weight-for-height or -length z score (adjusted mean difference: 1.07; 95% CI: 0.49,1.65, P < 0.001) and reduce the proportion of participants with delayed global development [adjusted RR (aRR): 0.49; 95% CI: 0.31, 0.77, P = 0.002], delayed gross motor development (aRR: 0.29; 95% CI: 0.13, 0.64, P = 0.002), delayed fine motor development (aRR: 0.59; 95% CI: 0.38, 0.91, P = 0.018), and delayed language development (aRR: 0.57; 95% CI: 0.34, 0.96, P = 0.036). Conclusions: High-dose vitamin D3 improved the mean weight-for-height or -length z score and developmental indexes in children receiving standard therapy for uncomplicated severe acute malnutrition in Pakistan. This trial was registered at clinicaltrials.gov as NCT03170479.


Assuntos
Transtornos da Nutrição Infantil/tratamento farmacológico , Colecalciferol/administração & dosagem , Transtornos da Nutrição do Lactente/tratamento farmacológico , Pré-Escolar , Colecalciferol/farmacologia , Dieta , Relação Dose-Resposta a Droga , Método Duplo-Cego , Feminino , Humanos , Lactente , Masculino , Vitaminas/administração & dosagem , Vitaminas/farmacologia
2.
J Steroid Biochem Mol Biol ; 175: 138-145, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-28161533

RESUMO

Vitamin D deficiency is common in patients with chronic obstructive pulmonary disease (COPD), yet a comprehensive analysis of environmental and genetic determinants of serum 25-hydroxyvitamin D (25[OH]D) concentration in patients with this condition is lacking. We conducted a multi-centre cross-sectional study in 278 COPD patients aged 41-92 years in London, UK. Details of potential environmental determinants of vitamin D status and COPD symptom control and severity were collected by questionnaire, and blood samples were taken for analysis of serum 25(OH)D concentration and DNA extraction. All participants performed spirometry and underwent measurement of weight and height. Quadriceps muscle strength (QS) was measured in 134 participants, and sputum induction with enumeration of lower airway eosinophil and neutrophil counts was performed for 44 participants. Thirty-seven single nucleotide polymorphisms (SNP) in 11 genes in the vitamin D pathway (DBP, DHCR7, CYP2R1, CYP27B1, CYP24A1, CYP27A1, CYP3A4, LRP2, CUBN, RXRA, and VDR) were typed using Taqman allelic discrimination assays. Linear regression was used to identify environmental and genetic factors independently associated with serum 25(OH)D concentration and to determine whether vitamin D status or genetic factors independently associated with % predicted forced expiratory volume in one second (FEV1), % predicted forced vital capacity (FVC), the ratio of FEV1 to FVC (FEV1:FVC), daily inhaled corticosteroid (ICS) dose, respiratory quality of life (QoL), QS, and the percentage of eosinophils and neutrophils in induced sputum. Mean serum 25(OH)D concentration was 45.4nmol/L (SD 25.3); 171/278 (61.5%) participants were vitamin D deficient (serum 25[OH]D concentration <50nmol/L). Lower vitamin D status was independently associated with higher body mass index (P=0.001), lower socio-economic position (P=0.037), lack of vitamin D supplement consumption (P<0.001), sampling in Winter or Spring (P for trend=0.006) and lack of a recent sunny holiday (P=0.002). Vitamin D deficiency associated with reduced % predicted FEV1 (P for trend=0.060) and % predicted FVC (P for trend=0.003), but it did not associate with FEV1:FVC, ICS dose, QoL, QS, or the percentage of eosinophils or neutrophils in induced sputum. After correction for multiple comparisons testing, genetic variation in the vitamin D pathway was not found to associate with serum 25(OH)D concentration or clinical correlates of COPD severity. Vitamin D deficiency was common in this group of COPD patients in the UK, and it associated independently with reduced % predicted FEV1 and FVC. However, genetic variation in the vitamin D pathway was not associated with vitamin D status or severity of COPD.


Assuntos
Doença Pulmonar Obstrutiva Crônica/epidemiologia , Deficiência de Vitamina D/epidemiologia , Vitamina D/análogos & derivados , Adulto , Idoso , Idoso de 80 Anos ou mais , Índice de Massa Corporal , Estudos Transversais , Sistema Enzimático do Citocromo P-450/sangue , Sistema Enzimático do Citocromo P-450/genética , Proteínas de Ligação a DNA/sangue , Proteínas de Ligação a DNA/genética , Eosinófilos/metabolismo , Eosinófilos/patologia , Feminino , Regulação da Expressão Gênica , Humanos , Londres/epidemiologia , Proteína-2 Relacionada a Receptor de Lipoproteína de Baixa Densidade/sangue , Proteína-2 Relacionada a Receptor de Lipoproteína de Baixa Densidade/genética , Masculino , Pessoa de Meia-Idade , Neutrófilos/metabolismo , Neutrófilos/patologia , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/sangue , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/genética , Prevalência , Doença Pulmonar Obstrutiva Crônica/sangue , Doença Pulmonar Obstrutiva Crônica/complicações , Doença Pulmonar Obstrutiva Crônica/genética , Grupos Raciais , Receptores de Calcitriol/sangue , Receptores de Calcitriol/genética , Receptores de Superfície Celular/sangue , Receptores de Superfície Celular/genética , Testes de Função Respiratória , Índice de Gravidade de Doença , Fatores de Transcrição/sangue , Fatores de Transcrição/genética , Vitamina D/sangue , Deficiência de Vitamina D/sangue , Deficiência de Vitamina D/complicações , Deficiência de Vitamina D/genética
3.
J Steroid Biochem Mol Biol ; 175: 88-96, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-27825992

RESUMO

Vitamin D deficiency is common in children with asthma, and it associates with poor asthma control, reduced forced expiratory volume in one second (FEV1) and increased requirement for inhaled corticosteroids (ICS). Cross-sectional studies investigating the prevalence, determinants and clinical correlates of vitamin D deficiency in adults with asthma are lacking. We conducted a multi-centre cross-sectional study in 297 adults with a medical record diagnosis of ICS-treated asthma living in London, UK. Details of potential environmental determinants of vitamin D status, asthma control and medication use were collected by questionnaire; blood samples were taken for analysis of serum 25(OH)D concentration and DNA extraction, and participants underwent measurement of weight, height and fractional exhaled nitric oxide concentration (FeNO), spirometry and sputum induction for determination of lower airway eosinophil counts (n=35 sub-group). Thirty-five single nucleotide polymorphisms (SNP) in 11 vitamin D pathway genes (DBP, DHCR7, RXRA, CYP2R1, CYP27B1, CYP24A1, CYP3A4 CYP27A1, LRP2, CUBN, VDR) were typed using Taqman allelic discrimination assays. Linear regression was used to identify environmental and genetic factors independently associated with serum 25(OH)D concentration, and to determine whether vitamin D status was independently associated with Asthma Control Test (ACT) score, ICS dose, FeNO, forced vital capacity (FVC), FEV1 or lower airway eosinophilia. Mean serum 25(OH)D concentration was 50.6nmol/L (SD 24.9); 162/297 (54.5%) participants were vitamin D deficient (serum 25(OH)D concentration <50nmol/L). Lower vitamin D status was associated with higher body mass index (P=0.014), non-White ethnicity (P=0.036), unemployment (P for trend=0.012), lack of vitamin D supplement use (P<0.001), sampling in Winter or Spring (P for trend <0.001) and lack of a recent sunny holiday abroad (P=0.030), but not with potential genetic determinants. Vitamin D status was not found to associate with any marker of asthma control investigated. Vitamin D deficiency is common among UK adults with ICS-treated asthma, and classical environmental determinants of serum 25(OH)D operate in this population. However, in contrast to studies conducted in children, we found no association between vitamin D status and markers of asthma severity or control.


Assuntos
Asma/epidemiologia , Deficiência de Vitamina D/epidemiologia , Vitamina D/análogos & derivados , Administração por Inalação , Adolescente , Corticosteroides/uso terapêutico , Adulto , Idoso , Antiasmáticos/uso terapêutico , Asma/sangue , Asma/complicações , Asma/tratamento farmacológico , Índice de Massa Corporal , Estudos Transversais , Sistema Enzimático do Citocromo P-450/sangue , Sistema Enzimático do Citocromo P-450/genética , Proteínas de Ligação a DNA/sangue , Proteínas de Ligação a DNA/genética , Eosinófilos/metabolismo , Eosinófilos/patologia , Feminino , Regulação da Expressão Gênica , Humanos , Londres/epidemiologia , Proteína-2 Relacionada a Receptor de Lipoproteína de Baixa Densidade/sangue , Proteína-2 Relacionada a Receptor de Lipoproteína de Baixa Densidade/genética , Masculino , Pessoa de Meia-Idade , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/sangue , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/genética , Grupos Raciais , Receptores de Calcitriol/sangue , Receptores de Calcitriol/genética , Receptores de Superfície Celular/sangue , Receptores de Superfície Celular/genética , Testes de Função Respiratória , Índice de Gravidade de Doença , Fatores de Transcrição/sangue , Fatores de Transcrição/genética , Vitamina D/sangue , Deficiência de Vitamina D/sangue , Deficiência de Vitamina D/complicações , Deficiência de Vitamina D/tratamento farmacológico
4.
J Steroid Biochem Mol Biol ; 164: 30-35, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-26776442

RESUMO

Despite the high prevalence of vitamin D deficiency among older adults in the UK, studies investigating the determinants of vitamin D status in this group are lacking. We conducted a cross-sectional study in 222 older adults living in sheltered accommodation in London, UK, who were screened for participation in a clinical trial of vitamin D supplementation for the prevention of acute respiratory infection. Details of potential demographic and lifestyle determinants of vitamin D status were collected by questionnaire and blood samples were taken for analysis of serum 25-hydroxyvitamin D (25[OH]D) concentration and DNA extraction. Fifteen single nucleotide polymorphisms (SNP) in 6 genes (DBP, DHCR7, CYP2R1, CYP27B1, CYP24A1, VDR) previously reported to associate with circulating 25(OH)D concentration were typed using Taqman allelic discrimination assays. Linear regression was used to identify environmental and genetic factors independently associated with serum 25(OH)D concentration. Mean serum 25(OH)D concentration was 42.7nmol/L (SD 22.0); 144/222 (64.9%) participants had serum 25(OH)D concentrations <50nmol/L. The following factors were independently associated with lower serum 25(OH)D concentration: non-white ethnicity (-8.6nmol/L, 95% CI -14.9 to -2.3, P=0.008); lack of vitamin D supplement consumption (-17.1nmol/L, 95% CI -23.3 to -10.9, P<0.001) vs. taking a daily supplement; sampling in Q1/January-March (-12.2nmol/L, 95% CI -21.5 to -2.9, P=0.01), and sampling in Q4/October-December (-10.3nmol/L, 95% CI -20.2 to -0.4, P=0.04) vs. sampling in Q3/July-September. None of the 15 SNP investigated independently associated with serum 25(OH)D concentration after correcting for multiple comparisons. In conclusion, vitamin D deficiency was highly prevalent among the older adults in this study; non-White ethnicity, lack of vitamin D supplement consumption and sampling in winter and spring independently associated with lower vitamin D status.


Assuntos
Predisposição Genética para Doença , Polimorfismo de Nucleotídeo Único , Deficiência de Vitamina D/sangue , Deficiência de Vitamina D/genética , Vitamina D/análogos & derivados , Vitamina D/genética , 25-Hidroxivitamina D3 1-alfa-Hidroxilase/genética , Idoso , Idoso de 80 Anos ou mais , Envelhecimento , Colestanotriol 26-Mono-Oxigenase/genética , Ensaios Clínicos como Assunto , Estudos de Coortes , Estudos Transversais , Família 2 do Citocromo P450/genética , Proteínas de Ligação a DNA/genética , Dieta , Suplementos Nutricionais , Feminino , Humanos , Londres , Masculino , Pessoa de Meia-Idade , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/genética , Receptores de Calcitriol/genética , Estações do Ano , Fatores de Transcrição/genética , Vitamina D/sangue , Vitamina D/uso terapêutico , Deficiência de Vitamina D/epidemiologia , Vitamina D3 24-Hidroxilase/genética
5.
Thorax ; 70(10): 953-60, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26063508

RESUMO

RATIONALE: Low-dose vitamin D supplementation is already recommended in older adults for prevention of fractures and falls, but clinical trials investigating whether higher doses could provide additional protection against acute respiratory infection (ARI) are lacking. OBJECTIVE: To conduct a clinical trial of high-dose versus low-dose vitamin D3 supplementation for ARI prevention in residents of sheltered-accommodation housing blocks ('schemes') and their carers in London, UK. MEASUREMENTS AND METHODS: Fifty-four schemes (137 individual participants) were allocated to the active intervention (vitamin D3 2.4 mg once every 2 months +10 µg daily for residents, 3 mg once every 2 months for carers), and 54 schemes with 103 participants were allocated to control (placebo once every 2 months +vitamin D3 10 µg daily for residents, placebo once every 2 months for carers) for 1 year. Primary outcome was time to first ARI; secondary outcomes included time to first upper/lower respiratory infection (URI/LRI, analysed separately), and symptom duration. MAIN RESULTS: Inadequate vitamin D status was common at baseline: 220/240 (92%) participants had serum 25(OH)D concentration <75 nmol/L. The active intervention did not influence time to first ARI (adjusted HR (aHR) 1.18, 95% CI 0.80 to 1.74, p=0.42). When URI and LRI were analysed separately, allocation to the active intervention was associated with increased risk of URI (aHR 1.48, 95% CI 1.02 to 2.16, p=0.039) and increased duration of URI symptoms (median 7.0 vs 5.0 days for active vs control, adjusted ratio of geometric means 1.34, 95% CI 1.09 to 1.65, p=0.005), but not with altered risk or duration of LRI. CONCLUSIONS: Addition of intermittent bolus-dose vitamin D3 supplementation to a daily low-dose regimen did not influence risk of ARI in older adults and their carers, but was associated with increased risk and duration of URI. TRIAL REGISTRATION NUMBER: clinicaltrials.gov NCT01069874.


Assuntos
Colecalciferol/uso terapêutico , Suplementos Nutricionais , Infecções Respiratórias/prevenção & controle , Vitaminas/uso terapêutico , Doença Aguda , Idoso , Cuidadores , Relação Dose-Resposta a Droga , Método Duplo-Cego , Esquema de Medicação , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Casas de Saúde
6.
Thorax ; 70(5): 451-7, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25724847

RESUMO

RATIONALE: Asthma exacerbations are commonly precipitated by viral upper respiratory infections (URIs). Vitamin D insufficiency associates with susceptibility to URI in patients with asthma. Trials of vitamin D in adults with asthma with incidence of exacerbation and URI as primary outcome are lacking. OBJECTIVE: To conduct a randomised controlled trial of vitamin D3 supplementation for the prevention of asthma exacerbation and URI (coprimary outcomes). MEASUREMENTS AND METHODS: 250 adults with asthma in London, UK were allocated to receive six 2-monthly oral doses of 3 mg vitamin D3 (n=125) or placebo (n=125) over 1 year. Secondary outcomes included asthma control test and St George's Respiratory Questionnaire scores, fractional exhaled nitric oxide and concentrations of inflammatory markers in induced sputum. Subgroup analyses were performed to determine whether effects of supplementation were modified by baseline vitamin D status or genotype for 34 single nucleotide polymorphisms in 11 vitamin D pathway genes. MAIN RESULTS: 206/250 participants (82%) were vitamin D insufficient at baseline. Vitamin D3 did not influence time to first severe exacerbation (adjusted HR 1.02, 95% CI 0.69 to 1.53, p=0.91) or first URI (adjusted HR 0.87, 95% CI 0.64 to 1.16, p=0.34). No clinically important effect of vitamin D3 was seen on any of the secondary outcomes listed above. The influence of vitamin D3 on coprimary outcomes was not modified by baseline vitamin D status or genotype. CONCLUSIONS: Bolus-dose vitamin D3 supplementation did not influence time to exacerbation or URI in a population of adults with asthma with a high prevalence of baseline vitamin D insufficiency. TRIAL REGISTRATION NUMBER: NCT00978315 (ClinicalTrials.gov).


Assuntos
Asma/complicações , Asma/prevenção & controle , Colecalciferol/administração & dosagem , Suplementos Nutricionais , Infecções Respiratórias/prevenção & controle , Vitaminas/administração & dosagem , Adulto , Estudos de Coortes , Método Duplo-Cego , Esquema de Medicação , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Infecções Respiratórias/epidemiologia , Fatores de Tempo
7.
Lancet Respir Med ; 3(2): 120-130, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25476069

RESUMO

BACKGROUND: Patients with chronic obstructive pulmonary disease (COPD) often have vitamin D deficiency, which is associated with increased susceptibility to upper respiratory infection-a major precipitant of exacerbation. Multicentre trials of vitamin D supplementation for prevention of exacerbation and upper respiratory infection in patients with COPD are lacking. We therefore investigated whether vitamin D3 (colecalciferol) supplementation would reduce the incidence of moderate or severe COPD exacerbations and upper respiratory infections. METHODS: We did a randomised, double-blind, placebo-controlled trial of vitamin D3 supplementation in adults with COPD in 60 general practices and four Acute National Health Service Trust clinics in London, UK. Patients were allocated to receive six 2-monthly oral doses of 3 mg vitamin D3 or placebo over 1 year in a 1:1 ratio using computer-generated permuted block randomisation. Participants and study staff were masked to treatment assignment. Coprimary outcomes were time to first moderate or severe exacerbation and first upper respiratory infection. Analysis was by intention to treat. A prespecified subgroup analysis was done to assess whether effects of the intervention on the coprimary outcomes were modified by baseline vitamin D status. This trial is registered with ClinicalTrials.gov, number NCT00977873. FINDINGS: 240 patients were randomly allocated to the vitamin D3 group (n=122) and placebo group (n=118). Vitamin D3 compared with placebo did not affect time to first moderate or severe exacerbation (adjusted hazard ratio 0·86, 95% CI 0·60-1·24, p=0·42) or time to first upper respiratory infection (0·95, 0·69-1·31, p=0·75). Prespecified subgroup analysis showed that vitamin D3 was protective against moderate or severe exacerbation in participants with baseline serum 25-hydroxyvitamin D concentrations of less than 50 nmol/L (0·57, 0·35-0·92, p=0·021), but not in those with baseline 25-hydroxyvitamin D levels of at least 50 nmol/L (1·45, 0·81-2·62, p=0·21; p=0·021 for interaction between allocation and baseline serum 25-hydroxyvitamin D status). Baseline vitamin D status did not modify the effect of the intervention on risk of upper respiratory infection (pinteraction=0·41). INTERPRETATION: Vitamin D3 supplementation protected against moderate or severe exacerbation, but not upper respiratory infection, in patients with COPD with baseline 25-hydroxyvitamin D levels of less than 50 nmol/L. Our findings suggest that correction of vitamin D deficiency in patients with COPD reduces the risk of moderate or severe exacerbation. FUNDING: UK National Institute for Health Research.


Assuntos
Colecalciferol/uso terapêutico , Suplementos Nutricionais , Doença Pulmonar Obstrutiva Crônica/dietoterapia , Vitaminas/uso terapêutico , Idoso , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Doença Pulmonar Obstrutiva Crônica/sangue , Doença Pulmonar Obstrutiva Crônica/complicações , Infecções Respiratórias/epidemiologia , Infecções Respiratórias/etiologia , Vitamina D/análogos & derivados , Vitamina D/sangue , Deficiência de Vitamina D/sangue , Deficiência de Vitamina D/complicações , Deficiência de Vitamina D/dietoterapia
8.
BMC Public Health ; 13: 999, 2013 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-24152375

RESUMO

BACKGROUND: The global prevalence of type 2 diabetes is increasing. Effective strategies to address this public health challenge are currently lacking. A number of epidemiological studies have reported associations between low concentrations of 25-hydroxy vitamin D and the incidence of diabetes, but a causal link has not been established. We investigate the effect of vitamin D supplementation on the metabolic status of individuals at increased risk of developing type 2 diabetes. METHODS/DESIGN: In a randomised double-blind placebo-controlled trial individuals identified as having a high risk of type 2 diabetes (non-diabetic hyperglycaemia or positive diabetes risk score) are randomised into one of three groups and given 4 doses of either placebo, or 100,000 IU Vitamin D2 (ergocalciferol) or 100,000 IU Vitamin D3 (cholecalciferol) at monthly intervals. The primary outcome measure is the change in glycated haemoglobin level between baseline and 4 months. Secondary outcome measures include blood pressure, lipid levels, apolipoproteins, highly sensitive C-reactive protein, parathyroid hormone (PTH) and safety of supplementation. and C-reactive protein. The trial is being conducted at two sites (London and Cambridge, U.K.) and a total of 342 participants are being recruited. DISCUSSION: Trial data examining whether supplementation of vitamin D improves glycaemic status and other metabolic parameters in people at risk of developing type 2 diabetes are sparse. This trial will evaluate the causal role of vitamin D in hyperglycaemia and risk of type 2 diabetes. Specific features of this trial include recruitment of participants from different ethnic groups, investigation of the relative effectiveness and safety of vitamin D2 and D3 and an evidence based approach to determination of the dose of supplementation. TRIAL REGISTRATION: EudraCT2009-011264-11; ISRCTN86515510.


Assuntos
Colecalciferol/uso terapêutico , Diabetes Mellitus Tipo 2/prevenção & controle , Suplementos Nutricionais/estatística & dados numéricos , Ergocalciferóis/uso terapêutico , Hiperglicemia/tratamento farmacológico , Adulto , Idoso , Glicemia/efeitos dos fármacos , Proteína C-Reativa/efeitos dos fármacos , Colecalciferol/administração & dosagem , Colecalciferol/sangue , Diabetes Mellitus Tipo 2/sangue , Método Duplo-Cego , Ergocalciferóis/administração & dosagem , Ergocalciferóis/sangue , Feminino , Seguimentos , Hemoglobinas Glicadas/efeitos dos fármacos , Humanos , Hiperglicemia/sangue , Londres , Masculino , Pessoa de Meia-Idade , Risco , Resultado do Tratamento , Vitaminas/administração & dosagem , Vitaminas/sangue , Vitaminas/uso terapêutico
9.
Proc Natl Acad Sci U S A ; 109(38): 15449-54, 2012 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-22949664

RESUMO

Calcidiol, the major circulating metabolite of vitamin D, supports induction of pleiotropic antimicrobial responses in vitro. Vitamin D supplementation elevates circulating calcidiol concentrations, and thus has a potential role in the prevention and treatment of infection. The immunomodulatory effects of administering vitamin D to humans with an infectious disease have not previously been reported. To characterize these effects, we conducted a detailed longitudinal study of circulating and antigen-stimulated immune responses in ninety-five patients receiving antimicrobial therapy for pulmonary tuberculosis who were randomized to receive adjunctive high-dose vitamin D or placebo in a clinical trial, and who fulfilled criteria for per-protocol analysis. Vitamin D supplementation accelerated sputum smear conversion and enhanced treatment-induced resolution of lymphopaenia, monocytosis, hypercytokinaemia, and hyperchemokinaemia. Administration of vitamin D also suppressed antigen-stimulated proinflammatory cytokine responses, but attenuated the suppressive effect of antimicrobial therapy on antigen-stimulated secretion of IL-4, CC chemokine ligand 5, and IFN-α. We demonstrate a previously unappreciated role for vitamin D supplementation in accelerating resolution of inflammatory responses during tuberculosis treatment. Our findings suggest a potential role for adjunctive vitamin D supplementation in the treatment of pulmonary infections to accelerate resolution of inflammatory responses associated with increased risk of mortality.


Assuntos
Tuberculose/imunologia , Vitamina D/metabolismo , Adulto , Peptídeos Catiônicos Antimicrobianos/farmacologia , Antituberculosos/farmacologia , Feminino , Regulação da Expressão Gênica , Genótipo , Humanos , Sistema Imunitário , Inflamação , Cinética , Masculino , Pessoa de Meia-Idade , Polimorfismo Genético , Análise de Regressão , Risco , Esteroides/química , Fatores de Tempo , Tuberculose/terapia , Vitamina D/uso terapêutico
10.
Lancet ; 377(9761): 242-50, 2011 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-21215445

RESUMO

BACKGROUND: Vitamin D was used to treat tuberculosis in the pre-antibiotic era, and its metabolites induce antimycobacterial immunity in vitro. Clinical trials investigating the effect of adjunctive vitamin D on sputum culture conversion are absent. METHODS: We undertook a multicentre randomised controlled trial of adjunctive vitamin D in adults with sputum smear-positive pulmonary tuberculosis in London, UK. 146 patients were allocated to receive 2·5 mg vitamin D(3) or placebo at baseline and 14, 28, and 42 days after starting standard tuberculosis treatment. The primary endpoint was time from initiation of antimicrobial treatment to sputum culture conversion. Patients were genotyped for TaqI and FokI polymorphisms of the vitamin D receptor, and interaction analyses were done to assess the influence of the vitamin D receptor genotype on response to vitamin D(3). This trial is registered with ClinicalTrials.gov number NCT00419068. FINDINGS: 126 patients were included in the primary efficacy analysis (62 assigned to intervention, 64 assigned to placebo). Median time to sputum culture conversion was 36·0 days in the intervention group and 43·5 days in the placebo group (adjusted hazard ratio 1·39, 95% CI 0·90-2·16; p=0.14). TaqI genotype modified the effect of vitamin D supplementation on time to sputum culture conversion (p(interaction)=0·03), with enhanced response seen only in patients with the tt genotype (8·09, 95% CI 1·36-48·01; p=0·02). FokI genotype did not modify the effect of vitamin D supplementation (p(interaction)=0·85). Mean serum 25-hydroxyvitamin D concentration at 56 days was 101·4 nmol/L in the intervention group and 22·8 nmol/L in the placebo group (95% CI for difference 68·6-88·2; p<0·0001). INTERPRETATION: Administration of four doses of 2·5 mg vitamin D(3) increased serum 25-hydroxyvitamin D concentrations in patients receiving intensive-phase treatment for pulmonary tuberculosis. Vitamin D did not significantly affect time to sputum culture conversion in the whole study population, but it did significantly hasten sputum culture conversion in participants with the tt genotype of the TaqI vitamin D receptor polymorphism. FUNDING: British Lung Foundation.


Assuntos
Antituberculosos/uso terapêutico , Colecalciferol/administração & dosagem , Tuberculose Pulmonar/tratamento farmacológico , Vitaminas/administração & dosagem , Adulto , Método Duplo-Cego , Feminino , Humanos , Masculino , Polimorfismo Genético , Receptores de Calcitriol/genética , Escarro/microbiologia , Taq Polimerase/genética , Adulto Jovem
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