Effect of vitamin D and inhaled corticosteroid treatment on lung function in children. DO IT Trial: vitamin D Outcomes and Interventions in Toddlers – a TARGet Kids! randomized controlled trial Serum vitamin D levels and severe asthma exacerbations in the Childhood Asthma Management Program study. Cord Blood Vitamin D Deficiency Is Associated With Respiratory Syncytial Virus Bronchiolitis Vitamin D supplementation for severe pneumonia — A randomized controlled trial Vitamin D status has a linear association with seasonal infections and lung function in British adults. Vitamin A supplementation in children with recurrent respiratory infections. The effect of vitamin D on airway reactivity and inflammation in asthmatic children: A double-blind placebo-controlled trial. Respiratory infections reduce the growth response to vitamin A supplementation in a randomized controlled trial. Randomized Trial of Vitamin D Supplementation and Risk of Acute Respiratory Infection in Mongolia Vitamin D3 supplementation in patients with chronic obstructive pulmonary disease (ViDiCO): a multicentre, double-blind, randomised controlled trial. Improved control of childhood asthma with low‐dose, short‐term vitamin D supplementation: a randomized, double‐blind, placebo‐controlled trial Vitamin D3 supplementation in patients with frequent respiratory tract infections: a randomised and double-blind intervention study Effect of High-Dose vs Standard-Dose Wintertime Vitamin D Supplementation on Viral Upper Respiratory Tract Infections in Young Healthy Children Vitamin D Deficiency Associated With Increased Incidence of Gastrointestinal and Ear Infections in School-age Children Vitamin D supplementation and upper respiratory tract infections in adolescent swimmers: a randomized controlled trial. Clinical trial of vitamin A as adjuvant treatment for lower respiratory tract infections.
RATIONALE Low vitamin D levels are associated with asthma and decreased airway responsiveness . Treatment with inhaled corticosteroids improves airway responsiveness and asthma control . OBJECTIVES To assess the effect of vitamin D levels on prebronchodilator FEV(1 ) , bronchodilator response , and responsiveness to methacholine ( PC(20 ) , provocative concentration of methacholine producing a 20 % decline in FEV(1 ) ) in patients with asthma treated with inhaled corticosteroids . METHODS We measured  25-hydroxyvitamin D levels  in the serum of children with persistent asthma at the time of enrollment in the Childhood Asthma Management Program . We divided subjects into the vitamin D sufficiency ( > 30 ng/ml ) , insufficiency ( 20 - 30 ng/ml ) , and deficiency ( < 20 ng/ml ) groups . Covariates included age , treatment , sex , body mass index , race , history of emergency department visits , hospitalizations , and season that vitamin D specimen was drawn . Our main outcome measures were change in prebronchodilator FEV(1 ) , bronchodilator response , and PC(20 ) from enrollment to 8 - 12 months . MEASUREMENTS AND MAIN RESULTS Of the 1,024 subjects , 663 ( 65 % ) were vitamin D sufficient , 260 ( 25 % ) were insufficient , and 101 ( 10 % ) were deficient . Vitamin D-deficient subjects were more likely to be older , African American , and have a higher body mass index compared with the vitamin D-sufficient and insufficient subjects . In the inhaled corticosteroid treatment group , prebronchodilator FEV(1 ) increased from r and omization to 12 months by 140 ml in the vitamin D-deficient group and prebronchodilator FEV(1 ) increased by 330 ml in the vitamin D insufficiency group and by 290 ml in the vitamin D sufficiency group ( P = 0.0072 ) , in adjusted models . CONCLUSIONS In children with asthma treated with inhaled corticosteroids , vitamin D deficiency is associated with poorer lung function than in children with vitamin D insufficiency or sufficiency Background Vitamin D levels are alarmingly low ( < 75 nmol/L ) in 65 - 70 % of North American children older than 1 year . An increased risk of viral upper respiratory tract infections ( URTI ) , asthma-related hospitalizations and use of anti-inflammatory medication have all been linked with low vitamin D. No study has determined whether wintertime vitamin D supplementation can reduce the risk of URTI and asthma exacerbations , two of the most common and costly illnesses of early childhood . The objectives of this study are : 1 ) to compare the effect of ‘ high dose ’ ( 2000 IU/day ) vs. ‘ st and ard dose ’ ( 400 IU/day ) vitamin D supplementation in achieving reductions in laboratory confirmed URTI and asthma exacerbations during the winter in preschool-aged Canadian children ; and 2 ) to assess the effect of ‘ high dose ’ vitamin D supplementation on vitamin D serum levels and specific viruses that cause URTI . Methods / Design This study is a pragmatic r and omized controlled trial . Over 4 successive winters we will recruit 750 healthy children 1–5 years of age . Participating physicians are part of a primary healthcare research network called TARGet Kids!. Children will be r and omized to the ‘ st and ard dose ’ or ‘ high dose ’ oral supplemental vitamin D for a minimum of 4 months ( 200 children per group ) . Parents will obtain a nasal swab from their child with each URTI , report the number of asthma exacerbations and complete symptom checklists . Unscheduled physician visits for URTIs and asthma exacerbations will be recorded . By May , a blood sample will be drawn to determine vitamin D serum levels . The primary analysis will be a comparison of URTI rate between study groups using a Poisson regression model . Secondary analyses will compare  vitamin D serum levels , asthma exacerbations and the frequency of specific viral agents between groups . Discussion Identifying whether vitamin D supplementation of preschoolers can reduce wintertime viral URTIs and asthma exacerbations and what dose is optimal may reduce population wide morbidity and associated health care and societal costs . This information will assist in determining practice and health policy recommendations related to vitamin D supplementation in healthy Canadian preschoolers BACKGROUND Asthma exacerbations , most often caused by respiratory tract infections , are the leading causes of asthma morbidity and comprise a significant proportion of asthma-related costs . Vitamin D status might play a role in preventing asthma exacerbations . OBJECTIVES We sought to assess the relationship between serum vitamin D levels and subsequent severe asthma exacerbations . METHODS We measured  25-hydroxyvitamin D levels in sera collected from 1024 children with mild-to-moderate persistent asthma at the time of enrollment in a multicenter clinical trial of children r and omized to receive budesonide , nedocromil , or placebo ( as-needed beta-agonists ) : the Childhood Asthma Management Program . Using multivariable modeling , we examined the relationship between baseline vitamin D levels and the odds of any hospitalization or emergency department visit over the 4 years of the trial . RESULTS Thirty-five percent of all subjects were  vitamin D insufficient , as defined by a level of 30 ng/mL or less 25-hydroxyvitamin D. Mean vitamin D levels were lowest in African American subjects and highest in white subjects . After adjusting for age , sex , body mass index , income , and treatment group , insufficient vitamin D status was associated with a higher odds of any hospitalization or emergency department visit ( odds ratio , 1.5 ; 95 % CI , 1.1 - 1.9 ; P = .01 ) . CONCLUSION Vitamin D insufficiency is common in this population of North American children with mild-to-moderate persistent asthma and is associated with higher odds of severe exacerbation over a 4-year period BACKGROUND : Respiratory syncytial virus ( RSV ) is the most important pathogen causing severe lower respiratory tract infection ( LRTI ) in infants . Epidemiologic and basic studies suggest that vitamin D may protect against RSV LRTI . OBJECTIVE : To determine the association between plasma vitamin D concentrations at birth and the subsequent risk of RSV LRTI . DESIGN : A prospect i ve birth cohort study was performed in healthy term neonates . Concentrations of 25-hydroxyvitamin D ( 25-OHD ) in cord blood plasma were related to RSV LRTI in the first year of life , defined as parent-reported LRTI symptoms in a daily log and simultaneous presence of RSV RNA in a nose-throat specimen . RESULTS : The study population included 156 neonates . Eighteen ( 12 % ) developed RSV LRTI . The mean plasma 25-OHD concentration was 82 nmol/L. Overall , 27 % of neonates had 25-OHD concentrations < 50 nmol/L , 27 % had 50 - 74 nmol/L and only 46 % had 25-OHD 75 nmol/L. Cord blood 25-OHD concentrations were strongly associated with maternal vitamin D3 supplementation during pregnancy . Concentrations of 25-OHD were lower in neonates who subsequently developed RSV LRTI compared with those who did not ( 65 nmol/L versus 84 nmol/L , P = .009 ) . Neonates born with 25-OHD concentrations < 50 nmol/L had a sixfold ( 95 % confidence interval : 1.6 - 24.9 ; P = .01 ) increased risk of RSV LRTI in the first year of life compared with those with 25-OHD concentrations ≥75 nmol/L. CONCLUSIONS : Vitamin D deficiency in healthy neonates is associated with increased risk of RSV LRTI in the first year of life . Intensified routine vitamin D supplementation during pregnancy may be a useful strategy to prevent RSV LRTI during infancy Objective To determine the role of oral vitamin D supplementation for resolution of severe pneumonia in under-five children . Design R and omized , double blind , placebo-controlled trial . Setting In patients from a tertiary care hospital . Participants Two hundred children [ mean ( SD ) age : 13.9 ( 11.7 ) months ; boys : 120 ] between 2 months to 5 years with severe pneumonia . Pneumonia was diagnosed in the presence of fever , cough , tachypnea ( as per WHO cut-offs ) and crepitations . Children with pneumonia and chest indrawing or at least one of the danger sign ( inability to feed , lethargy , cyanosis ) were diagnosed as having severe pneumonia . The two groups were comparable for baseline characteristics including age , anthropometry , socio-demographic profile , and clinical and laboratory parameters . InterventionOral vitamin D ( 1000 IU for < 1 year and 2000 IU for > 1 year ) ( n=100 ) or placebo ( lactose ) ( n=100 ) once a day for 5 days , from enrolment . Both the groups received antibiotics as per the Indian Academy of Pediatrics guidelines , and supportive care ( oxygen , intravenous fluids and monitoring ) . Outcome variables Primary : time to resolution of severe pneumonia . Secondary : duration of hospitalization and time to resolution of tachypnea , chest retractions and inability to feed . Results Median duration ( SE , 95 % CI ) of resolution of severe pneumonia was similar in the two groups [ vitamin D : 72 ( 3.7 , 64.7–79.3 ) hours ; placebo : 64 ( 4.5 , 55.2–72.8 ) hours ] . Duration of hospitalization and time to resolution of tachypnea , chest retractions , and inability to feed were also comparable between the two groups . ConclusionS hort-term supplementation with oral vitamin D ( 1000–2000 IU per day for 5 days ) has no beneficial effect on resolution of severe pneumonia in under-five children . Further studies need to be conducted with higher dose of Vitamin D or longer duration of supplementation to corroborate these findings Higher vitamin D concentrations have been proposed as a protective ' seasonal stimulus ' against influenza , and there are suggestions for associations with other aspects of respiratory health . The aim of the present study was to investigate the relationship of current vitamin D status ( measured by 25-hydroxyvitamin D , 25(OH)D ) with  respiratory infections and lung function .  We used cross-sectional data from 6789 participants in the nationwide 1958 British birth cohort who had measurements of 25(OH)D , lung function ( forced expiratory volume in 1 s ( FEV1 ) and forced vital capacity ( FVC ) ) and respiratory infections available from the age of 45 years . In this population , the prevalence of respiratory infections had a strong seasonal pattern in the opposite direction to the pattern for 25(OH)D concentrations . Each 10 nmol/l increase in 25(OH)D was associated with a 7 % lower risk of infection ( 95 % CI 3 , 11 % ) after adjustment for adiposity , lifestyle and socio-economic factors . For FEV1 and FVC , each 10 nmol/l increase in 25(OH)D was associated with 8 ( 95 % CI 3 , 13 ) ml and 13 ( 95 % CI 7 , 20 ) ml higher volume , respectively , after controlling for covariates . Associations of 25(OH)D with FEV1 and FVC were only slightly attenuated after further adjustment for infection and other respiratory illness . In conclusion , vitamin D status had a linear relationship with respiratory infections and lung function . R and omised controlled trials are warranted to investigate the role of vitamin D supplementation on respiratory health and to establish the underlying mechanisms Vitamin A deficiency predisposes children to infection by suppression of humoral and cell-mediated immunity as well by changes in the respiratory epithelium . To evaluate the effect of vitamin A supplementation in children with recurrent respiratory infections a clinical trial was conducted . 61 children ( 37 boys and 24 girls ) aged 12 - 60 months with a history of recurrent respiratory infections were enrolled in the study with informed consent from the parents . All the included children were followed-up monthly in the outpatient clinic using a st and ard follow-up protocol . Parents were given a monthly calendar and were instructed to record the occurrence of any of the following symptoms daily : runny or blocked nose sore/scratchy throat dry cough chesty or moist cough wheezy breathing shortness of breath and fever . Overall the findings demonstrated that there was no difference between the groups even when the children were stratified by pre-supplementation vitamin A level or wheezing episodes . There was also no significant difference in the mean number of outpatient clinic visits for inter-current illnesses ( 2.1 + or- 2.4 vs. 1.34 + or- 1.4 p = 0.17 ) or in the mean weight gain between the two groups ( 0.6679 + or- 0.7385 = or- 0.78 kg p = 0.72 placebo vs. vitamin A. Based on the findings trials evaluating different dosages frequency of administration and formulations of vitamin A are required to delineate supplementation regimes which may result in sustained improvement in the retinol levels and thereby have a better clinical effect BACKGROUND Cross-sectional studies have reported an association of vitamin D deficiency with increased asthma prevalence and severity , and with allergies . The effect of vitamin D as sole therapy on airway hyper-reactivity ( AHR ) and airway inflammation has not been reported . AIM To evaluate the effect of vitamin D therapy on AHR as assessed by methacholine concentration , causing a 20 % reduction in FEV1 ( PC20 -FEV1 ) and fractional exhaled nitric oxide ( FeNO ) , systemic markers of allergy and inflammation , and exhaled breath condensate cytokines . PATIENTS AND METHODS Children aged 6 - 18 years with a clinical diagnosis of mild asthma currently not receiving anti-inflammatory therapy and with low vitamin D levels were included in this r and omized , double-blind , placebo-controlled study assessing the effect of 6 weeks of treatment with oral vitamin D 14,000 units once weekly or placebo . RESULTS Of the 39 patients included , 20 received vitamin D treatment and 19 received a placebo . Vitamin D replacement result ed in a significant increase in vitamin levels , which remained unchanged in the placebo group ( P < 0.0001 ) . There was no change in IgE , eosinophil count , high sensitivity C-reactive protein , FeNO levels or PC20 -FEV1 following treatment . Similar values of exhaled breath condensate cytokines ( IL4 , IL5 , IL10 , IL17 , and γ interferon ) were observed in both groups . CONCLUSIONS In our small group of children with mild asthma , no difference could be demonstrated between the effect of vitamin D and placebo , despite significant increases in vitamin D blood levels . Larger interventional studies are needed to fully explore the possible effect of vitamin D in asthma BACKGROUND Studies on the effect of vitamin A supplementation on growth have yielded various results . It is possible that such growth is dependent on the burden of infectious diseases in the population . METHODS We analysed data from a r and omized , double-masked , placebo-controled trial to examine the role of respiratory infections and diarrhoea in modifying the growth response to vitamin A supplementation . A single high dose of vitamin A or placebo was given every 4 months to 1405 children aged 6 - 48 months , and 4430 child treatment cycles were used in this analysis . RESULTS Vitamin A supplementation modestly improved linear but not ponderal growth of children who experienced little respiratory infection and especially of those who had vitamin A intake below the normative requirement ( < 400 RE/day ) . Children who received vitamin A and were free of respiratory infection grew 0.22 cm/4 months ( 95 % CI : 0.08 , 0.37 ) more in height than the placebo group , but those with > or = 21.5 % of days of respiratory infection did not show a significant growth response to vitamin A supplementation . Children who experienced no respiratory infection and had vitamin A intake < 400 RE/day benefited most , gaining 0.31 cm/4 months ( 95 % CI : 0.10 , 0.52 ) more in height compared to the placebo group . Diarrhoea was associated with poorer growth , but did not significantly modify the effect of  vitamin A supplementation  on growth . CONCLUSIONS Vitamin A supplementation improves the linear growth of children who have a low intake of vitamin A but this impact is muted with increasing levels of respiratory infections OBJECTIVE : Observational studies suggest that serum levels of 25-hydroxyvitamin D ( 25[OH]D ) are inversely associated with acute respiratory infections ( ARIs ) . We hypothesized that vitamin D supplementation of children with vitamin D deficiency would lower the risk of ARIs . METHODS : By using cluster r and omization , classrooms of 744 Mongolian schoolchildren were r and omly assigned to different treatments in winter ( January – March ) . This analysis focused on a subset of 247 children who were assigned to daily ingestion of unfortified regular milk ( control ; n = 104 ) or milk fortified with 300 IU of vitamin D3 ( n = 143 ) . This comparison was double-blinded . The primary outcome was the number of parent-reported ARIs over the past 3 months . RESULTS : At baseline , the median serum 25(OH)D level was 7 ng/mL ( interquartile range : 5–10 ng/mL ) . At the end of the trial , follow-up was 99 % ( n = 244 ) , and the median 25(OH)D levels of children in the control versus vitamin D groups was significantly different ( 7 vs 19 ng/mL ; P < .001 ) . Compared with controls , children receiving vitamin D reported significantly fewer ARIs during the study period ( mean : 0.80 vs 0.45 ; P = .047 ) , with a rate ratio of 0.52 ( 95 % confidence interval : 0.31–0.89 ) . Adjusting for age , gender , and history of wheezing , vitamin D continued to halve the risk of ARI ( rate ratio : 0.50 [ 95 % confidence interval : 0.28–0.88 ] ) . Similar results were found among children either below or above the median 25(OH)D level at baseline ( rate ratio : 0.41 vs 0.57 ; Pinteraction = .27 ) . CONCLUSIONS : Vitamin D supplementation significantly reduced the risk of ARIs in winter among Mongolian children with vitamin D deficiency 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 r and omised , double-blind , placebo-controlled trial of vitamin D3 supplementation in adults with COPD in 60 general practice s 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 r and omisation . Participants and study staff were masked to treatment assignment . Co primary 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 co primary outcomes were modified by baseline vitamin D status . This trial is registered with Clinical Trials.gov , number NCT00977873 . FINDINGS 240 patients were r and omly 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 In our prior r and omized trial on preventing influenza , asthma attacks as a secondary outcome occurred less often in the vitamin D group than in the placebo group . We aim ed to clarify whether low‐dose , short‐term vitamin D supplementation , in addition to st and ard treatments , improves control of childhood asthma Background Low serum levels of 25-hydroxyvitamin D3 are associated with an increased risk of respiratory tract infections ( RTIs ) . Clinical trials with vitamin D3 against various infections have been carried out but data are so far not conclusive . Thus , there is a need for additional r and omised controlled trials of effects of vitamin D3 on infections . Objective To investigate if supplementation with vitamin D3 could reduce infectious symptoms and antibiotic consumption among patients with antibody deficiency or frequent RTIs . Design A double-blind r and omised controlled trial . Setting Karolinska University Hospital , Huddinge . Participants 140 patients with antibody deficiency ( selective IgA subclass deficiency , IgG subclass deficiency , common variable immune disorder ) and patients with increased susceptibility to RTIs ( > 4 bacterial RTIs/year ) but without immunological diagnosis . Intervention Vitamin D3 ( 4000 IU ) or placebo was given daily for 1 year . Primary and secondary outcome measures The primary endpoint was an infectious score based on five parameters : symptoms from respiratory tract , ears and sinuses , malaise and antibiotic consumption . Secondary endpoints were serum levels of 25-hydroxyvitamin D3 , microbiological findings and levels of antimicrobial peptides ( LL-37 , HNP1–3 ) in nasal fluid . Results The overall infectious score was significantly reduced for patients allocated to the vitamin D group ( 202 points ) compared with the placebo group ( 249 points ; adjusted relative score 0.771 , 95 % CI 0.604 to 0.985 , p=0.04 ) . Limitations A single study centre , small sample size and a selected group of patients . The sample size calculation was performed using p=0.02 as the significance level whereas the primary and secondary endpoints were analysed using the conventional p=0.05 as the significance level . Conclusions Supplementation with vitamin D3 may reduce disease burden in patients with frequent RTIs Importance Epidemiological studies support a link between low 25-hydroxyvitamin D levels and a higher risk of viral upper respiratory tract infections . However , whether winter supplementation of vitamin D reduces the risk among children is unknown . Objective To determine whether high-dose vs st and ard-dose vitamin D supplementation reduces the incidence of wintertime upper respiratory tract infections in young children . Design , Setting , and Participants A r and omized clinical trial was conducted during the winter months between September 13 , 2011 , and June 30 , 2015 , among children aged 1 through 5 years enrolled in TARGet Kids ! , a multisite primary care practice –based research network in Toronto , Ontario , Canada . Interventions Three hundred forty-nine participants were r and omized to receive 2000 IU/d of vitamin D oral supplementation ( high-dose group ) vs 354 participants who were r and omized to receive 400 IU/d ( st and ard-dose group ) for a minimum of 4 months between September and May. Main Outcome Measures The primary outcome was the number of laboratory-confirmed viral upper respiratory tract infections based on parent-collected nasal swabs over the winter months . Secondary outcomes included the number of influenza infections , noninfluenza infections , parent-reported upper respiratory tract illnesses , time to first upper respiratory tract infection , and serum 25-hydroxyvitamin D levels at study termination . Results Among 703 participants who were r and omized ( mean age , 2.7 years , 57.7 % boys ) , 699 ( 99.4 % ) completed the trial . The mean number of laboratory-confirmed upper respiratory tract infections per child was 1.05 ( 95 % CI , 0.91 - 1.19 ) for the high-dose group and 1.03 ( 95 % CI , 0.90 - 1.16 ) for the st and ard-dose group , for a between-group difference of 0.02 ( 95 % CI , −0.17 to 0.21 ) per child . There was no statistically significant difference in number of laboratory-confirmed infections between groups ( incidence rate ratio [ RR ] , 0.97 ; 95 % CI , 0.80 - 1.16 ) . There was also no significant difference in the median time to the first laboratory-confirmed infection : 3.95 months ( 95 % CI , 3.02 - 5.95 months ) for the high-dose group vs 3.29 months ( 95 % CI , 2.66 - 4.14 months ) for the st and ard-dose group , or number of parent-reported upper respiratory tract illnesses between groups ( 625 for high-dose vs 600 for st and ard-dose groups , incidence RR , 1.01 ; 95 % CI , 0.88 - 1.16 ) . At study termination , serum 25-hydroxyvitamin D levels were 48.7 ng/mL ( 95 % CI , 46.9 - 50.5 ng/mL ) in the high-dose group and 36.8 ng/mL ( 95 % CI , 35.4 - 38.2 ng/mL ) in the st and ard-dose group . Conclusions and Relevance Among healthy children aged 1 to 5 years , daily administration of 2000 IU compared with 400 IU of vitamin D supplementation did not reduce overall wintertime upper respiratory tract infections . These findings do not support the routine use of high-dose vitamin D supplementation in children for the prevention of viral upper respiratory tract infections . Trial Registration clinical trials.gov Identifier : Background : Vitamin D deficiency ( VDD ) is highly prevalent among children worldwide . The effects of VDD include alterations of the immune response and increased risk of infection but little evidence exists in school-age children . We investigated the association of vitamin D status with morbidity in a prospect i ve study of school-age children from Bogotá , Colombia . Methods : We measured plasma 25-hydroxyvitamin D ( 25(OH)D ) concentrations in a r and om sample of 475 children ( mean ± st and ard deviation age : 8.9 ± 1.6 years ) and followed them for an academic year . Caregivers were asked to record daily information on the incidence of morbidity episodes using pictorial diaries . Baseline vitamin D status was classified according to 25(OH)D concentrations as deficient ( < 50 nmol/L ) , insufficient ( ≥50 and < 75 nmol/L ) or sufficient ( ≥75 nmol/L ) . We used Poisson regression to estimate incidence rate ratios and 95 % confidence intervals for days with diarrhea , vomiting , diarrhea with vomiting , cough with fever and earache or discharge with fever , comparing vitamin D-deficient with vitamin D-sufficient children . Estimates were adjusted for child ’s age , sex and household socioeconomic status . Results : The prevalence of VDD was 10 % ; an additional 47 % of children were vitamin D-insufficient . VDD was associated with increased rates of diarrhea with vomiting ( adjusted incidence rate ratio : 2.05 ; 95 % confidence interval : 1.19 , 3.53 ) and earache/discharge with fever ( adjusted incidence rate ratio : 2.36 ; 95 % confidence interval : 1.26 , 4.44 ) . VDD was not significantly related to cough with fever . Conclusions : These results suggest that VDD is related to increased incidence of gastrointestinal and ear infections in school-age children . The effect of correcting VDD on reducing risk of these infections needs to be tested in supplementation trials Observational studies identified associations between vitamin D insufficiency ( serum 25(OH)D < 30ng·ml-1 ) and risk of upper respiratory infection ( URI ) .  Swimmers are highly prone to URIs , which might hinder their performance . The aim of this study was to examine if vitamin D3 supplementation reduces URI burden in vitamin D-insufficient swimmers . Fifty-five competitive adolescent swimmers with vitamin D insufficiency were r and omized to receive vitamin D3 ( 2,000IU·d-1 ) or placebo for 12 winter weeks . A URI symptom question naire was completed weekly . Serum 25(OH)D concentrations were measured by radio-immunoassay before and after supplementation . We used linear regression to examine the relation between the change in 25(OH)D concentrations during the trial , and the duration and severity of URIs . There were no between-group differences in the frequency , severity , or duration of URIs . Exploratory analyses revealed that in the placebo group only , the change in 25(OH)D concentrations during the trial was highly associated with the duration of URIs ( r = -0.90,p < .001 ) , and moderately associated with the severity of URIs ( r = -0.65,p = .043 ) . The between-group differences for duration  were highly significant . Vitamin D3 supplementation in adolescent swimmers with vitamin D insufficiency did not reduce URI burden . However , larger decreases in serum 25(OH)D concentrations were associated with significantly longer and more severe URI episodes OBJECTIVE To test the efficacy of a high dose of vitamin A as adjuvant treatment for radiographically confirmed cases of acute lower respiratory tract infection ( ALRI ) . DESIGN R and omized , double-masked , placebo-controlled clinical trial . SETTING Two large urban hospitals in Guatemala City . PATIENTS Sequential sample of 263 children aged 3 to 48 months , identified in the emergency departments and admitted to the hospital . INTERVENTIONS Vitamin A ( 100,000 IU for children less than 1 year of age , and 200,000 IU for older children ) or placebo in addition to st and ard treatment for ALRI which included antibiotics , oxygen , bronchodilators , and intravenously administered solutions . MEASUREMENTS AND MAIN RESULTS The children were assessed every 8 hours . There were neither statistically nor clinical ly significant differences by treatment group in the rate of normalization in respiratory rate , oxygen saturation , temperature , or clinical score . Duration of hospitalization was not different by treatment group . Adverse outcomes ( mechanical ventilation , prolonged hospitalization , readmission or transfer , and death ) were equally distributed between the two groups . CONCLUSIONS Treatment with high doses of vitamin A over and above st and ard care for infants and children with non-measles-related ALRI is not efficacious for the current episode . Additional trials among population s in which vitamin A deficiency is more prevalent and severe should be considered
Children with LRTI were found to have significantly lower mean vitamin D levels as compared to controls There was likewise a correlation between vitamin D levels and incidence and severity of LRTI .
Studies related to vitamin D deficiency and lower respiratory tract infections ( LRTI ) in children have inconsistent findings .
The objective of this systematic review was to assess the prevalence of vitamin D deficiency in children with LRTI , and to evaluate the correlation between vitamin D levels and the incidence and severity of LRTI .