Vitamin D, tuberculin skin test conversion, and latent tuberculosis in Mongolian school-age children: a randomized, double-blind, placebo-controlled feasibility trial

Oral vitamin D supplementation on the prevention of peritoneal dialysis-related peritonitis: A pilot randomised controlled trial

OBJECTIVE

Peritoneal dialysis (PD)-related peritonitis is independently associated with low serum 25-hydroxy vitamin D [25(OH)D] levels. Our objective is to examine the feasibility of conducting a large, randomised controlled trial to determine the effects of vitamin D supplementation on the risk of PD-related peritonitis.

DESIGN

Pilot, prospective, open-label randomised controlled trial.

SETTING

Peking University First Hospital, China.

PARTICIPANTS

Patients receiving PD who had recovered from a recent episode of peritonitis between 30 September 2017 and 28 May 2020.

INTERVENTIONS

Oral natural vitamin D supplementation (2000 IU per day) versus no vitamin D supplementation for 12 months.

PRIMARY AND SECONDARY OUTCOME MEASURES

Primary outcomes were feasibility (recruitment success, retention, adherence, safety) and fidelity (change in serum 25(OH)D level during follow-up) for a large, randomised controlled trial in the future to determine the effects of vitamin D on PD-related peritonitis. Secondary outcomes were time to peritonitis occurrence and outcome of subsequent peritonitis.

RESULTS

Overall, 60 among 151 patients were recruited (recruitment rate was 39.7%, 95% CI 31.9-47.5%, recruitment rate among eligible patients was 61.9%, 95% CI 52.2-71.5%). Retention and adherence rates were 100.0% (95% CI 100.0-100.0%) and 81.5% (95% CI 66.8-96.1%), respectively. During follow-up, serum 25(OH)D levels increased in the vitamin D (VD) group (from 19.25 ± 10.11 nmol/L to 60.27 ± 23.29 nmol/L after 6 months, p < 0.001, n = 31), and remained higher (p < 0.001) than those in the control group (n = 29). No differences were observed between the two groups with respect to time to subsequent peritonitis (hazard ratio 0.85, 95% CI 0.33-2.17) or any of the peritonitis outcomes. Adverse events were uncommon.

CONCLUSIONS

A randomised controlled trial of the effect of vitamin D supplementation on peritonitis occurrence in patients receiving PD is feasible, safe and results in adequate serum 25(OH)D levels.

Vitamin D: immune function, inflammation, infections and auto-immunity

Vitamin D plays an active role beyond mineral metabolism and skeletal health, including regulation of the immune system. Vitamin D deficiency is widely prevalent, and observational studies link low vitamin D status to a risk of infections and auto-immune disorders. Reports indicate an inverse relationship between vitamin D status and such conditions. This review details vitamin D signalling interactions with the immune system and provides experimental and clinical evidence evaluating vitamin D status, vitamin D supplementation and host susceptibility to infections, inflammation and auto-immunity. The published literature including related reviews, systematic reviews, meta-analyses, randomised controlled trials (RCTs), observational studies and basic science reports have been synthesised. Meta-analyses of observational studies have demonstrated a link between low vitamin D status and risk of acute respiratory infections, COVID-19 disorders, multiple sclerosis, type 1 diabetes (T1DM), inflammatory bowel disease (IBD), systemic lupus erythematosus and other auto-immune disorders. Observational studies suggest that vitamin D supplementation may protect against several infectious and auto-immune conditions. Meta-analyses of RCTs had mixed results, demonstrating a small protective role for vitamin D supplementation against acute respiratory infections, especially in those with vitamin D deficiency and children, and providing modest benefits for the management of T1DM and IBD. Vitamin D status is inversely associated with the incidence of several infectious and auto-immune conditions. Supplementation is recommended for those with vitamin D deficiency or at high risk of deficiency, and it might provide additional benefit in acute respiratory infections and certain auto-immune conditions.

Oral vitamin D supplementation and body weight in children and adolescents: a systematic review and meta-analysis of randomized controlled trials

This study was designed to ascertain whether oral vitamin D supplementation (oral supplementation and fortified foods) is associated with changes in body weight measures in children and adolescents, using a systematic review and meta-analysis of randomized controlled trials (RCTs). PubMed, Scopus, Cochrane, and Web of Science databases were searched from inception to October 28, 2022. The mean difference and corresponding 95% confidence interval (CI) of interested outcomes were pooled using a random-effects model. Twenty-one RCTs were included in the meta-analysis, and the results showed a significant decrease in body mass index (BMI) following vitamin D supplementation in children and adolescents (n = 9 studies, 1029 participants; weighted mean difference: - 0.43 kg/m², 95% CI: - 0.79, - 0.08; P = 0.02; I² = 58.5%). Overall, oral vitamin D supplementation had no significant effect on body weight and other anthropometric indices, including fat mass, lean mass, waist circumference, BMI Z-score, and height. Although results of body weight changed to significant after sensitivity analysis (WMD = 0.39 kg, 95% CI = 0.01, 0.78; P = 0.04; I² = 0%, P-heterogeneity = 0.71), we also found significant weight gain in healthy pediatric population, and when the dose of vitamin D supplementation was up to 600 IU/day, the certainty of evidence was very low for weight, moderate for height and BMI, and low for the remaining outcomes.

CONCLUSION

Our results suggest that vitamin D supplementation may lead to a statistically significant weight gain in children and adolescents, while BMI was reduced. Although no significant change was observed in height, it seems vitamin D supplementation may elicit these changes by increasing skeletal growth; however, this remains to be verified. Further high-quality RCTs, with longer duration and larger sample sizes, are needed to yield more certain evidence in this regard.

WHAT IS KNOWN

• Available evidence indicates an inverse association between body weight/fat mass and vitamin D status in children and adolescents; however, findings regarding the effect of vitamin D supplementation on anthropometric measurements in children are controversial.

WHAT IS NEW

• Our results showed a significant decrease in BMI following vitamin D supplementation in children. • A significant weight gain also was observed after sensitivity analysis, and in healthy pediatric population, and when the dose of vitamin D supplementation was up to 600 IU/day.

Multiple Sclerosis in Mongolia; the First Study Exploring Predictors of Disability and Depression in Mongolian MS Patients

Mongolia is located at 45° north latitude in the center of the Asian continent, and about 80% of the territory is at 1000 m above sea level. Epidemiologically, multiple sclerosis (MS) has not been investigated in Mongolia, although there have been a few MS case reports. We investigated the characteristics of MS in Mongolia for the first time, focusing on the association between MS-related parameters and depression levels. We initiated cross-sectional analyses, using data from 27 MS patients aged 20 to 60 years in Ulaanbaatar, Mongolia. The patients completed a questionnaire on their lifestyles and clinical information. We classified the MS patients on the basis of disability levels using the expanded disability status scale (EDSS) scores: 11.1% mild disability and 88.9% moderate to severe disability (median EDSS score, 5.5). We also classified the patients on the basis of depression levels using the 9-item patient health questionnaire (PHQ-9) scores: 44.4% mild depression, 40.7% moderate depression, and 14.8% severe depression (mean PHQ-9's score, 9.96 ± 5.05). We used multivariate logistical regression analyses to identify predictors of EDSS or PHQ-9 scores. Disability levels were associated with vision and balance problems. Depression levels were associated with corticosteroid treatment; no patients were treated with disease-modifying drugs (DMDs). The odds ratios for disease onset age and treatment duration were associated with EDSS scores. In conclusion, MS onset age and treatment duration were independent predicting factors influencing the level of disability. Appropriate DMD treatment would lower the disability and depression levels.

Efficacy and safety of vitamin D in tuberculosis patients: a systematic review and meta-analysis

BACKGROUND

Evidence from the basic research and epidemiological studies indicates a beneficial effect of vitamin D in the treatment of tuberculosis (TB). However, the evidence from randomized controlled trials (RCTs) is inconsistent.

OBJECTIVES

This systematic review and meta-analysis was performed to synthesize evidence regarding role of vitamin D versus placebo for the management of TB.

MATERIALS AND METHODS

We searched PubMed and Cochrane Clinical Trial Registry for RCTs comparing vitamin D versus placebo for the treatment of TB. RCTs enrolling adult patients with TB receiving vitamin D in addition to standard treatment were included. Data were pooled using random effects model. The study was conducted according to PRISMA guidelines and protocol was registered with PROSPERO (CRD42016052841).

RESULTS

Of 605 identified references, 12 RCTs were included. The overall risk of bias in included studies was low or unclear. There was no significant difference between vitamin D and placebo group for any outcomes of efficacy (time to culture conversion, time to smear conversion, rate of culture conversion, and rate of smear conversion) or safety (mortality, serious adverse events, and nonserious adverse events).

CONCLUSION

Vitamin D administered with standard treatment has no beneficial effect in the TB patients as compared to the placebo.

Interventions for High-Burden Infectious Diseases in Children and Adolescents: A Meta-analysis

BACKGROUND

Approximately 2.2 million deaths were reported among school-age children and young people in 2019, and infectious diseases remain the leading causes of morbidity and mortality, especially in low and middle-income countries. We aim to synthesize evidence on interventions for high-burden infectious diseases among children and adolescents aged 5 to 19 years.

METHODS

We conducted a comprehensive literature search until December 31, 2020. Two review authors independently screened studies for relevance, extracted data, and assessed risk of bias.

RESULTS

We included a total of 31 studies, including 81 596 participants. Sixteen studies focused on diarrhea; 6 on tuberculosis; 2 on human immunodeficiency virus; 2 on measles; 1 study each on acute respiratory infections, malaria, and urinary tract infections; and 2 studies targeted multiple diseases. We did not find any study on other high burden infectious diseases among this age group. We could not perform meta-analysis for most outcomes because of variances in interventions and outcomes. Findings suggests that for diarrhea, water treatment, water filtration, and zinc supplementation have some protective effect. For tuberculosis, peer counseling, contingency contract, and training of health care workers led to improvements in tuberculosis detection and treatment completion. Continuation of cotrimoxazole therapy reduced the risk of tuberculosis and hospitalizations among human immunodeficiency virus-infected children and reduced measles complications and pneumonia cases among measles-infected children. Zinc supplementation led to a faster recovery in urinary tract infections with a positive effect in reducing symptoms.

CONCLUSIONS

There is scarcity of data on the effectiveness of interventions for high-burden infectious diseases among school-aged children and adolescents.

Vitamin D and tuberculosis in children: a role in the prevention or treatment of the disease?

Despite the growing number of published studies, the role of vitamin D in the prevention or treatment of tuberculosis remains unclear. In this review we analyze current scientific literature to provide evidence about the relationship between vitamin D and TB, with a special focus on the pediatric population. While in vitro studies have shown relevant antimycobacterial immune-stimulatory and immunosuppressive effects of vitamin D, this has not panned out in vivo with active TB. On the contrary, there is some evidence that this tool could work as prevention - both against TB infection as well as progression from latent to active infection. However, only a few studies have evaluated this correlation in children. The potential link between tuberculosis and vitamin D levels is promising. If effective, vitamin D supplementation of at-risk populations would be an affordable public health intervention, particularly in light of the worldwide increase in identified TB cases and drug-resistance. Vitamin D might represent a new, affordable, safe and easy to access drug for the prevention and treatment of TB. For stronger evidence, considering the features of infection (relative low incidence of reactivation of latent infection in immunocompetent patients) we need clinical trials with large numbers of participants conducted in endemic regions with a prolonged follow-up time.

Prevalence and Determinants of Vitamin D Deficiency in 1825 Cape Town Primary Schoolchildren: A Cross-Sectional Study

Vitamin D deficiency (25-hydroxyvitamin D[25(OH)D] <50 nmol/L) is common among adults in Cape Town, South Africa, but studies investigating vitamin D status of children in this setting are lacking. We conducted a cross-sectional study to determine the prevalence and determinants of vitamin D deficiency in 1825 Cape Town schoolchildren aged 6−11 years. Prevalence of vitamin D deficiency was 7.6% (95% Confidence Interval [CI] 6.5% to 8.9%). Determinants of vitamin D deficiency included month of sampling (adjusted odds ratio [aOR] for July−September vs. January−March 10.69, 95% CI 5.02 to 22.77; aOR for October−December vs. January−March 6.73, 95% CI 2.82 to 16.08), older age (aOR 1.25 per increasing year, 95% CI: 1.01−1.53) and higher body mass index (BMI; aOR 1.24 per unit increase in BMI-for-age Z-score, 95% CI: 1.03−1.49). In a subset of 370 participants in whom parathyroid hormone (PTH) concentrations were measured; these were inversely related to serum 25(OH)D concentrations (p < 0.001). However, no association between participants with hyperparathyroidism (PTH >6.9 pmol/L) and vitamin D deficiency was seen (p = 0.42). In conclusion, we report that season is the major determinant of vitamin D status among Cape Town primary schoolchildren, with prevalence of vitamin D deficiency ranging from 1.4% in January−March to 22.8% in July−September.

Effects of Vitamin D supplementation on resolution of fever and cough in children with pulmonary tuberculosis: A randomized double-blind controlled trial in Indonesia

Background

Various studies in adults have shown a strong association between vitamin D and tuberculosis (TB), both in terms of vitamin D status and the benefits of vitamin D in managing TB. Studies on vitamin D and its relationship with childhood TB still lack in Indonesia as a country with the second-highest TB incidence globally. This study evaluated the effect of vitamin D supplementation on resolution of cough and fever in Indonesian children with pulmonary TB.

Methods

We conducted a randomized controlled trial of vitamin D supplementation in children with pulmonary TB and vitamin D insufficiency. Patients were randomly allocated with 1:1 ratio to receive either 1000 IU vitamin D or placebo daily after starting standard TB treatment. The primary outcome in this study was the resolution of fever and cough symptoms reviewed weekly after starting the treatment until the symptoms are resolved. The secondary outcome in this study was 25-hydroxyvitamin D serum level and nutritional status which was reviewed at the end of the trial. Intention to treat analyses were applied. Differences in clinical outcomes between two groups were calculated using Mann-Whitney U test or χ² test, where appropriate.

Findings

A total of 84 patients met the inclusion criteria, aged 6 to 18 years old, newly diagnosed with pulmonary TB and vitamin D insufficiency. Eighty patients (95,2%) completed the six months follow-up. Faster resolution of fever, cough, improved malnutrition status, and higher vitamin D level were found in the intervention group compared to the placebo group (all P < 0.001).

Conclusions

Vitamin D is beneficial in improving fever and cough resolution, and improving nutritional status in children with pulmonary TB and vitamin D insufficiency. Determination of adequate supplementation levels of more than 1000 IU requires further research to achieve normal vitamin D levels during the duration of treatment for pulmonary TB in children.

Trial registration

ClinicalTrials.gov (NCT05073965).

Vitamin D, respiratory infections, and chronic disease: Review of meta-analyses and randomized clinical trials

BACKGROUND

Observational studies have suggested associations of vitamin D deficiency (VDD) with respiratory tract infections, impaired bone health, and myriad chronic diseases.

OBJECTIVE

To assess potential causal relationships between vitamin D supplementation and a reduced risk of these conditions, a review of the evidence across available meta-analyses of randomized control trials (RCTs) and RCTs was performed.

METHOD

PubMed, Embase, Cochrane Library, and Web of Science were searched from their inception to March 2021. We included only RCTs and meta-analyses of RCTs focusing on the association between vitamin D and respiratory disease, bone health, cardiovascular disease (CVD), diabetes mellitus, and cancer.

RESULTS

A total of 107 RCTs and 62 meta-analysis of RCTs were included. Although most RCTs did not support benefits of vitamin D supplementation, suggestive evidence for benefit was found in populations at greater risk of VDD and for acute respiratory infections, fractures in institutionalized older adults, type 2 diabetes among patients with prediabetes, and cancer mortality. In contrast, no compelling evidence for benefit was found for other respiratory conditions, fractures in community-dwelling adults, falls, cancer incidence, or CVD.

CONCLUSIONS

Current evidence from RCTs and meta-analyses of RCTs is inconsistent regarding the effects of vitamin D supplementation on respiratory infections and chronic diseases. Individuals most likely to benefit are those with baseline VDD or with selected high-risk conditions. Public health initiatives are needed to eliminate VDD globally, and future research will be enhanced by a 'precision prevention' approach to identify those most likely to benefit from vitamin D supplementation.

Vitamin D and the risk of latent tuberculosis infection: a systematic review and meta-analysis

Objective

Latent tuberculosis infection (LTBI) may be a risk of developing tuberculosis (TB) and thus a health hazard. The aim of this meta-analysis is to explore the association between vitamin D and LTBI.

Methods

Databases including PubMed, Embase, Scopus, and ProQuest were electronically searched to identify observational or interventional studies that reported the association between vitamin D and LTBI. The retrieval time is limited from inception to 30 September 2021. Two reviewers independently screened literature, extracted data, and assessed risk bias of included studies. Meta-analysis was performed by using STATA 12.0 software.

Results

A total of 5 studies involving 2 case–control studies and 3 cohort studies were included. The meta-analysis result showed that the risk of LTBI among individuals was not associated with high vitamin D level (OR 0.51, 95% CI 0.05–5.65, P = 0.58). The result from cohort studies also suggested that relatively high vitamin D level was not a protective factor for LTBI (RR = 0.56, 95%CI 0.19–1.67, P = 0.300).

Conclusions

Our meta-analysis suggested that serum vitamin D levels were not associated with incidence of LTBI, and relatively high serum vitamin D level was not a protective factor for LTBI. Further RCTs are needed to verify whether sufficient vitamin D levels and vitamin D supplementation reduces the risk of LTBI.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-022-01830-5.

Autophagy Induction as a Host-Directed Therapeutic Strategy against Mycobacterium tuberculosis Infection

Tuberculosis (TB), a bacterialinfectious disease caused by Mycobacterium tuberculosis (M.tb), which causes significant mortality in humans worldwide. Current treatment regimen involve the administration of multiple antibiotics over the course of several months that contributes to patient non-compliance leading to relapse and the development of drug-resistant M.tb (MDR and XDR) strains. Together, these facts highlight the need for the development of shorter TB treatment regimens. Host-directed therapy (HDT) is a new and emerging concept that aims to augment host immune response using drugs/compounds with or without adjunct antibiotics against M.tb infection. Autophagy is a natural catabolic mechanism of the cell that involves delivering the cytosolic constituents to the lysosomes for degradation and recycling the components; thereby maintaining the cellular and energy homoeostasis of a cell. However, over the past decade, an improved understanding of the role of autophagy in immunity has led to autophagy activation by using drugs or agents. This autophagy manipulation may represent a promising host-directed therapeutic strategy for human TB. However, current clinical knowledge on implementing autophagy activation by drugs or agents, as a stand-alone HDT or as an adjunct with antibiotics to treat human TB is insufficient. In recent years, many reports on high-throughput drug screening and measurement of autophagic flux by fluorescence, high-content microscopy, flow cytometry, microplate reader and immunoblotting have been published for the discovery of drugs that modulate autophagy. In this review, we discuss the commonly used chemical screening approaches in mammalian cells for the discovery of autophagy activating drugs against M.tbinfection. We also summarize the various autophagy-activating agents, both pre-clinical candidates and compounds approved for advanced clinical investigation during mycobacterial infection. Finally, we discuss the opportunities and challenges in using autophagy activation as HDT strategy to improve TB outcome and shorten treatment regimen.

Perspective: Vitamin D supplementation prevents rickets and acute respiratory infections when given as daily maintenance but not as intermittent bolus: implications for COVID-19

The value of vitamin D supplementation in the treatment or prevention of various conditions is often viewed with scepticism as a result of contradictory results of randomised trials. It is now becoming apparent that there is a pattern to these inconsistencies. A recent large trial has shown that high-dose intermittent bolus vitamin D therapy is ineffective at preventing rickets - the condition that is most unequivocally caused by vitamin D deficiency. There is a plausible biological explanation since high-dose bolus replacement induces long-term expression of the catabolic enzyme 24-hydroxylase and fibroblast growth factor 23, both of which have vitamin D inactivating effects. Meta-analyses of vitamin D supplementation in prevention of acute respiratory infection and trials in tuberculosis and other conditions also support efficacy of low dose daily maintenance rather than intermittent bolus dosing. This is particularly relevant during the current COVID-19 pandemic given the well-documented associations between COVID-19 risk and vitamin D deficiency. We would urge that clinicians take note of these findings and give strong support to widespread use of daily vitamin D supplementation.

Protocol for a case-control study of vitamin D status, adult multidrug-resistant tuberculosis disease and tuberculosis infection in Mumbai, India

INTRODUCTION

Vitamin D status may be an important determinant of multidrug-resistant tuberculosis (MDR-TB) infection, progression to disease and treatment outcomes. Novel and potentially cost-effective therapies such as vitamin D supplementation are needed to stem the tide of TB and MDR-TB globally, particularly in India, a country that accounts for the largest fraction of the world's TB incidence and MDR-TB incidence, and where vitamin D deficiency is endemic. While vitamin D has shown some promise in the treatment of MDR-TB, its role in the context of MDR-TB infection and progression to disease is largely unknown.

METHODS AND ANALYSIS

Through a case-control study in Mumbai, India, we aim to examine associations between vitamin D status and active MDR-TB and to investigate vitamin D status and TB infection among controls. Cases are adult outpatient pulmonary patients with MDR-TB recruited from two public TB clinics. Controls are recruited from the cases' household contacts and from non-respiratory departments of the facilities where cases were recruited. Cases and controls are assessed for serum 25-hydroxyvitamin D concentration, nutrient intake, diet quality, anthropometry and other relevant clinical and sociodemographic parameters. Controls undergo additional clinical assessments to rule out active TB and laboratory assessments to determine presence of TB infection. Statistical analysis investigates associations between vitamin D status and active MDR-TB and between vitamin D status and TB infection among controls, accounting for potential confounding effects of diet, anthropometry and other covariates.

ETHICS AND DISSEMINATION

This study has been approved by Harvard T.H. Chan School of Public Health Institutional Review Board; Foundation for Medical Research Institutional Research Ethics Committee and Health Ministry's Screening Committee of the Indian Council for Medical Research. Permission was granted by the Municipal Corporation of Greater Mumbai, India, a collaborating partner on this research. Outcomes will be disseminated through publication and scientific presentation.

TRIAL REGISTRATION NUMBER

NCT04342598.

Vitamin D Supplements for Prevention of Tuberculosis Infection and Disease

BACKGROUND

Vitamin D metabolites support innate immune responses to Mycobacterium tuberculosis. Data from phase 3, randomized, controlled trials of vitamin D supplementation to prevent tuberculosis infection are lacking.

METHODS

We randomly assigned children who had negative results for M. tuberculosis infection according to the QuantiFERON-TB Gold In-Tube assay (QFT) to receive a weekly oral dose of either 14,000 IU of vitamin D3 or placebo for 3 years. The primary outcome was a positive QFT result at the 3-year follow-up, expressed as a proportion of children. Secondary outcomes included the serum 25-hydroxyvitamin D (25[OH]D) level at the end of the trial and the incidence of tuberculosis disease, acute respiratory infection, and adverse events.

RESULTS

A total of 8851 children underwent randomization: 4418 were assigned to the vitamin D group, and 4433 to the placebo group; 95.6% of children had a baseline serum 25(OH)D level of less than 20 ng per milliliter. Among children with a valid QFT result at the end of the trial, the percentage with a positive result was 3.6% (147 of 4074 children) in the vitamin D group and 3.3% (134 of 4043) in the placebo group (adjusted risk ratio, 1.10; 95% confidence interval [CI], 0.87 to 1.38; P = 0.42). The mean 25(OH)D level at the end of the trial was 31.0 ng per milliliter in the vitamin D group and 10.7 ng per milliliter in the placebo group (mean between-group difference, 20.3 ng per milliliter; 95% CI, 19.9 to 20.6). Tuberculosis disease was diagnosed in 21 children in the vitamin D group and in 25 children in the placebo group (adjusted risk ratio, 0.87; 95% CI, 0.49 to 1.55). A total of 29 children in the vitamin D group and 34 in the placebo group were hospitalized for treatment of acute respiratory infection (adjusted risk ratio, 0.86; 95% CI, 0.52 to 1.40). The incidence of adverse events did not differ significantly between the two groups.

CONCLUSIONS

Vitamin D supplementation did not result in a lower risk of tuberculosis infection, tuberculosis disease, or acute respiratory infection than placebo among vitamin D-deficient schoolchildren in Mongolia. (Funded by the National Institutes of Health; ClinicalTrials.gov number, NCT02276755.).

Effectiveness of vitamin D supplementation on the outcome of pulmonary tuberculosis treatment in adults: a meta-analysis of randomized controlled trials

Supplemental Digital Content is available in the text

Background:

Tuberculosis (TB) is one of the most debilitating diseases worldwide. Current studies have shown that vitamin D plays a significant role in host immune defense against Mycobacterium tuberculosis, but clinical trials reported inconsistent results. Therefore, we systematically reviewed the literature to investigate whether vitamin D supplementation could improve the effect of anti-TB therapy.

Methods:

We systematically searched PubMed, Embase, and the Cochrane Central Register of Controlled Trials from their inception to February 8th, 2019 for randomized controlled trials on vitamin D supplementation in patients with pulmonary TB receiving anti-TB therapy. The primary outcomes were time to sputum culture and smear conversion and proportion of participants with negative sputum culture. The secondary outcomes were clinical response to treatment and adverse events. A random-effects model was used to pool studies. Data were analyzed using RevMan 5.3 software.

Results:

Five studies with a total of 1126 participants were included in our meta-analysis. Vitamin D supplementation did not shorten the time to sputum culture and smear conversion (hazard ratio [HR] 1.04, 95% confidence interval [CI] 0.89–1.23, P = 0.60; HR 1.15, 95% CI 0.93–1.41, P = 0.20, respectively) and did not lead to an increase in the proportion of participants with negative sputum culture (relative risk [RR] 1.04, 95% CI 0.97–1.11, P = 0.32). However, it reduced the time to sputum culture conversion in the sub-group of participants with TaqI tt genotype (HR 8.09, 95% CI 1.39–47.09, P = 0.02) and improved the multidrug-resistant (MDR) TB sputum culture conversion rate (RR 2.40, 95% CI 1.11–5.18, P = 0.03). There was no influence on secondary outcomes.

Conclusions:

Vitamin D supplementation had no beneficial effect on anti-TB treatment, but it reduced the time to sputum culture conversion in participants with tt genotype of the TaqI vitamin D receptor gene polymorphism and improved the MDR TB sputum culture conversion rate.

Insights on patterns of developmental disturbances from the analysis of linear enamel hypoplasia in a Neolithic sample from Liguria (northwestern Italy)

OBJECTIVE

To assess developmental disturbances through the analysis of linear enamel hypoplasia (LEH) frequency and to infer environmental stress and life history within Neolithic communities from Liguria (Italy).

MATERIALS

43 unworn/minimally worn permanent anterior teeth of 13 individuals recovered from nearby caves and dated to c. 4800-4400 cal. BCE.

METHODS

LEH defects were identified with high-resolution macrophotos of dental replicas, age at LEH was calculated via perikymata counts. LEH defects matched between two or more teeth were considered as systemic disturbances. LEH frequency by age classes was analyzed via GLZ and Friedman ANOVA.

RESULTS

Number of matched defects per individual range between 2-12. The mean LEH per individual was highest in the 2.5-2.99 age category, with a significant increase relative to earlier growth stages, followed by a decline.

CONCLUSION

LEH may reflect life-history in the local ecology of Neolithic Liguria, where several individuals with osteoarticular tuberculosis have been recorded. Disease burden may have triggered developmental disturbances around the time of weaning. Age at first defect was negatively correlated with age at death and positively with the total number of defects, suggesting that early stress may have affected survivorship.

SIGNIFICANCE

The study contributes to the reconstruction of ecological pressures among Neolithic people of Liguria, and informs on environmental challenges during the Neolithic adaptive expansion.

LIMITATIONS

The visual examination of macrophotos is prone to observer error; mid-crown tends to display more visible LEH due to tooth architecture.

SUGGESTIONS FOR FURTHER RESEARCH

Apply different quantitative methods to examine severity and duration of disturbances.

Environmental correlates of growth patterns in Neolithic Liguria (northwestern Italy)

OBJECTIVE

This study evaluates patterns of human growth in the Neolithic to make inferences about environmental correlates of developmental disturbances.

MATERIALS

33 children/adolescents from the Neolithic of Liguria (Italy), 29 of which date between 4,800-4,400 cal BCE.

METHODS

Neolithic patterns of growth are compared with a modern sample (the Denver Growth Study; DGS). Dental development was used to determine age at death. Proxies for postcranial maturation are femoral length and proportion of mean adult femoral length attained.

RESULTS

Ligurian children show growth faltering compared to DGS, especially between 4 and 9 years of age. Between 1 and 2 years, and in later childhood and adolescence, values are more similar or higher than DGS, when using the proportion of adult femoral length attained.

CONCLUSIONS

The pattern of growth in Ligurian Neolithic children may reflect a deprived and highly-infectious environment: three individuals show skeletal lesions consistent with tuberculosis. The relatively faster growth in infancy may result from the buffering provided by maternal milk. Older children and adolescents may exhibit catch-up growth.

SIGNIFICANCE

This study contributes to our understanding of Neolithic selective pressures and possible biocultural adaptive strategies.

LIMITATIONS

The cross-sectional nature of the data and the small sample size make it unclear whether the observed pattern is representative of the growth patterns in the living population. The possibility that adults are stunted undermines the interpretation of optimal growth in the first years.

SUGGESTIONS FOR FURTHER RESEARCH

Refine age estimates, increase sample size through the study of other bone elements.

Vitamin D-Cathelicidin Axis: at the Crossroads between Protective Immunity and Pathological Inflammation during Infection

Vitamin D signaling plays an essential role in innate defense against intracellular microorganisms via the generation of the antimicrobial protein cathelicidin. In addition to directly binding to and killing a range of pathogens, cathelicidin acts as a secondary messenger driving vitamin D-mediated inflammation during infection. Recent studies have elucidated the biological and clinical functions of cathelicidin in the context of vitamin D signaling. The vitamin D-cathelicidin axis is involved in the activation of autophagy, which enhances antimicrobial effects against diverse pathogens. Vitamin D studies have also revealed positive and negative regulatory effects of cathelicidin on inflammatory responses to pathogenic stimuli. Diverse innate and adaptive immune signals crosstalk with functional vitamin D receptor signals to enhance the role of cathelicidin action in cell-autonomous effector systems. In this review, we discuss recent findings that demonstrate how the vitamin D-cathelicidin pathway regulates autophagy machinery, protective immune defenses, and inflammation, and contributes to immune cooperation between innate and adaptive immunity. Understanding how the vitamin D-cathelicidin axis operates in the host response to infection will create opportunities for the development of new therapeutic approaches against a variety of infectious diseases.

The association between vitamin D status and infectious diseases of the respiratory system in infancy and childhood

PURPOSE

Respiratory tract infections (RTIs) are a major cause of illness worldwide and the most common cause of hospitalization for pneumonia and bronchiolitis. These two diseases are the leading causes of morbidity and mortality among children under 5 years of age. Vitamin D is believed to have immunomodulatory effects on the innate and adaptive immune systems by modulating the expression of antimicrobial peptides, like cathelicidin, in response to both viral and bacterial stimuli. The aim of this review is to summarize the more recently published data with regard to potential associations of 25-hydroxyvitamin D [25(OH)D] with infectious respiratory tract diseases of childhood and the possible health benefits from vitamin D supplementation.

METHODS

The literature search was conducted by using the PubMed, Scopus, and Google Scholar databases, with the following keywords: vitamin D, respiratory tract infection, tuberculosis, influenza, infancy, and childhood.

RESULTS

Several studies have identified links between inadequate 25(OH)D concentrations and the development of upper or lower respiratory tract infections in infants and young children. Some of them also suggest that intervention with vitamin D supplements could decrease both child morbidity and mortality from such causes.

CONCLUSIONS

Most studies agree in that decreased vitamin D concentrations are prevalent among most infants and children with RTIs. Also, normal to high-serum 25(OH)D appears to have some beneficial influence on the incidence and severity of some, but not all, types of these infections. However, studies with vitamin D supplementation revealed conflicting results as to whether supplementation may be of benefit, and at what doses.

Effects of Vitamin D Supplementation and Seasonality on Circulating Cytokines in Adolescents: Analysis of Data From a Feasibility Trial in Mongolia

Vitamin D deficiency is prevalent in human populations and has been linked to immune dysfunction. Here we explored the effects of cholecalciferol supplementation on circulating cytokines in severely vitamin D deficient [blood 25(OH)D << 30 nmol/L] adolescents aged 12–15 from Mongolia. The study included 28 children receiving 800 IU daily cholecalciferol for 6 months spanning winter and spring, and 30 children receiving placebo during the same period. The levels of 25(OH)D were assessed at baseline, 3 and 6 months. Twenty-one cytokines were measured in serum at baseline and at 6 months. Changes in 25(OH)D and cytokines were assessed using paired parametric tests. The median blood 25(OH)D concentration at baseline was 13.7 nmol/L (IQR = 10.0–21.7). Supplementation tripled blood 25(OH)D levels (p < 0.001) and was associated with elevated interleukin (IL)-6 (p = 0.043). The placebo group had reduced macrophage inflammatory protein (MIP)-1α (p = 0.007) and IL-8 (p = 0.034) at 6 months. Although limited by a small sample size, these findings suggest that cholecalciferol supplementation and seasonality may impact systemic immunity in adolescents, identifying chemokines as potentially important biomarkers of vitamin D status in this Northeast Asian population. Larger clinical trials are warranted to validate these results.

Clinical Trial Registration:www.ClinicalTrial.org, Identifier: NCT01244204.

Efeitos contrastantes da vitamina D sobre a resposta imune inata e adquirida e seu impacto na recuperação da tuberculose

A vitamina D é um hormônio essencial para o organismo, podendo ser obtida da dieta ou, principalmente, gerada pela pele após exposição à luz solar ultravioleta B. Na sua forma ativa (1,25(OH)2D) ela controla a absorção de cálcio e fósforo do intestino para a corrente sanguínea e participa de diversos processos celulares e fisiológicos. A ligação da 1,25(OH)2D ao receptor da vitamina D (VDR) presente em diversas células, como as células do sistema imunológico, induz a transcrição de genes que podem, por exemplo, modular a resposta imune inata e adquirida. A deficiência de vitamina D ou do VDR é associada a problemas de saúde como desordens esqueléticas, hipertensão, doenças cardiovasculares, diabetes mellitus, dislipidemias, doenças autoimunes e doenças infecciosas. Neste sentido, a suplementação com vitamina D tem sido proposta como uma possível medida preventiva, podendo ser aplicada em muitas patologias, em especial na tuberculose. Principal causa de morte por um único agente infeccioso, a tuberculose é responsável por cerca de 1,3 milhões de óbitos por ano no mundo. Publicações recentes apontam efeitos diversos da vitamina D na resposta imune inata e adquirida. A 1,25(OH)2D3 na presença do interferon (IFN)-γ é capaz de aumentar a atividade bactericida do macrófago contra o M. tuberculosis, aumentando a produção de peptídios antimicrobianos e estimulando a autofagia, favorecendo assim a lise de bacilos localizados em fagossomos. Por outro lado, a vitamina D em linfócitos T mostra efeito tolerogênico que favorece o controle de respostas inflamatórias excessivas. Neste trabalho de revisão são apresentados estudos recentes envolvendo efeitos da vitamina D na resposta imune inata e adquirida. Além disso, considerações sobre deficiência de vitamina D e maior risco de contrair tuberculose, e efeitos contrastantes da suplementação com vitamina D na prevenção e tratamento da TB, são discutidos.

A systematic review and meta-analysis of the response of serum 25-hydroxyvitamin D concentration to vitamin D supplementation from RCTs from around the globe

BACKGROUND/OBJECTIVES

Optimal doses of vitamin D (VitD) supplement in different populations are unclear. We aim to evaluate the relationship between VitD supplementation and post-intervention serum 25-hydroxyvitamin D [25(OH)D] concentration, to provide a recommended dosage of VitD for achieving an optimal 25(OH)D concentration for different populations.

SUBJECTS/METHODS

Literature search was conducted in Embase, etc. Randomized controlled trials about VitD supplemental intakes and their effect on 25(OH)D concentration were enrolled. The effect on 25(OH)D concentration between different supplementation doses in each population group was compared by meta-analysis. Multivariate meta-regression model is utilized to establish reference intake dosage of VitD.

RESULTS

A total of 136 articles were included about children (3-17 years), adults (18-64 years), postmenopausal women, the elderly ( >64 years), pregnant, or lactating women. Overall, intervention groups obtained higher 25(OH)D concentration than controls and there was obvious dose-response effect between intake dose and 25(OH)D concentration. Baseline 25(OH)D concentration and age were significant indicators for 25(OH)D concentration. To reach sufficient 25(OH)D concentration (75 nmol/L), the recommended VitD supplemental intakes was 1340 and 2250 IU/day for children and pregnant women, 2519 and 797 IU/day for European adults aged 18-64 and 65-85 years, 729, 2026, and 1229 IU/day for adults in North America, Asia and Middle East and Africa, respectively.

CONCLUSIONS

Regional- and age-specific recommended dosages of VitD supplements for population to achieve optimal 25(OH)D concentrations have been suggested.

Randomized trial of three doses of vitamin D to reduce deficiency in pregnant Mongolian women

BACKGROUND

In winter in Mongolia, 80% of adults have 25-hydroxyvitamin D (25(OH)D) concentrations <25 nmol/l (<10 ng/ml) and 99% have <50 nmol/l (<20 ng/ml). The vitamin D dose to avert deficiency during pregnancy in this population is unknown.

METHODS

We conducted a randomized, controlled, double-blind trial of daily 600, 2000, or 4000 IU vitamin D₃ for pregnant women in Mongolia (Clinicaltrials.gov #NCT02395081). We examined 25(OH)D concentrations at baseline (12-16 weeks' gestation), 36-40 weeks' gestation and in umbilical cord blood, using enzyme linked fluorescent assay. Sample size was determined to detect 0.4 standard deviation differences in 25(OH)D concentrations with 80% power.

FINDINGS

119 pregnant women were assigned 600 IU, 121 assigned 2000 IU and 120 assigned 4000 IU from February 2015 through December 2016. Eighty-eight percent of participants took ≥80% of assigned supplements. At baseline, 25(OH)D concentrations were similar across arms; overall mean ± standard deviation concentration was 19 ± 22 nmol/l; 91% were < 50 nmol/l. At 36-40 weeks, 25(OH)D concentrations increased to 46 ± 21, 70 ± 23, and 81 ± 29 nmol/l for women assigned 600, 2000, and 4000 IU, respectively (p < 0.0001 across arms; p = 0.002 for 2000 vs. 4000 IU). Mean umbilical cord 25(OH)D concentrations differed by study arm (p < 0.0001 across arms; p < 0.0001 for 2000 vs. 4000 IU) and were proportional to maternal concentrations. There were no adverse events, including hypercalcemia, attributable to vitamin D supplementation.

INTERPRETATION

Daily supplementation of 4000 IU during pregnancy is safe and achieved higher maternal and neonatal 25(OH)D concentrations than 2000 IU. Daily 600 IU supplements are insufficient to prevent vitamin D deficiency in Mongolia. FUND: Anonymous foundation and Brigham and Women's Hospital.

Autophagy: A new strategy for host-directed therapy of tuberculosis

Tuberculosis (TB), which is primarily caused by the major etiologic agent Mycobacterium tuberculosis (Mtb), remains a serious infectious disease worldwide. Recently, much effort has been made to develop novel/improved therapies by modulating host responses to TB (i.e., host-directed therapy). Autophagy is an intracellular catabolic process that helps maintain homeostasis or the removal of invading pathogens via a lysosomal degradation process. The activation of autophagy by diverse drugs or agents may represent a promising treatment strategy against Mtb infection, even to drug-resistant strains. Important mediators of autophagy activation include vitamin D receptor signaling, the AMP-activated protein kinase pathway, sirtuin 1 activation, and nuclear receptors. High-throughput approaches have identified numerous natural and synthetic compounds that enhance antimicrobial defense against Mtb infection through autophagy. In this review, we discuss the current knowledge of, advancements in, and perspectives on new therapeutic strategies targeting autophagy against TB. Understanding the mechanisms and key players involved in modulating antibacterial autophagy will provide innovative improvements in anti-TB therapy via an autophagy-targeting approach.

Abbreviations: TB: Tuberculosis; Mtb: Mycobacterium tuberculosis; HDT: host-directed therapy; MDR: multidrug resistant; XDR: extensively drug resistant; LAP: LC3-associated phagocytosis; ROS: reactive oxygen species; VDR: vitamin D receptor; TFEB: transcription factor EB; ERRα: estrogen-related receptor α; PGC1α: PPARγ coactivator-1 α

Vitamin D Levels in Active TB, Latent TB, Non-TB Pneumonia and Healthy Children: A Prospective Observational Study

BACKGROUND

Growing evidence suggests that vitamin D deficiency might be implicated in the development of active tuberculosis (TB). We evaluated vitamin D levels in children with active TB compared to children with latent TB infection (LTBI), non-TB pneumonia (NTBP) and healthy controls to determine if there was a difference.

METHODS

In this prospective study, vitamin D levels were measured and compared between the four groups and adjusted for age, ethnicity, gender and season of sample collection.

RESULTS

Fifty-seven children were included: 24.6% active TB, 28.1% LTBI, 22.8% NPTB and 24.6% healthy controls. 36.8% of all children tested had an insufficient or deficient vitamin D level. Vitamin D level was significantly lower in active TB compared to other groups (p = 0.004).

CONCLUSIONS

Our study showed a correlation between hypovitaminosis D and active pulmonary TB.

Daily adjunctive therapy with vitamin D3 and phenylbutyrate supports clinical recovery from pulmonary tuberculosis: a randomized controlled trial in Ethiopia

OBJECTIVE

Immunotherapy using vitamin D (vitD₃ ) and phenylbutyrate (PBA) may support standard drug regimens used to treat infectious diseases. We investigated if vitD₃ + PBA enhanced clinical recovery from pulmonary tuberculosis (TB).

METHODS

A randomized controlled trial was conducted in Addis Ababa, Ethiopia. Patients with smear-positive or smear-negative TB received daily oral supplementation with 5000 IU vitD₃ and 2 × 500 mg PBA or placebo for 16 weeks, together with 6-month chemotherapy. Primary end-point: reduction of a clinical composite TB score at week 8 compared with baseline using modified intention-to-treat (mITT, n = 348) and per-protocol (n = 296) analyses. Secondary end-points: primary and modified TB scores (week 0, 4, 8, 16, 24), sputum conversion, radiological findings and plasma 25(OH)D₃ concentrations.

RESULTS

Most subjects had low baseline plasma 25(OH)D₃ levels that increased gradually in the vitD₃ + PBA group compared with placebo (P < 0.0001) from week 0 to 16 (mean 34.7 vs. 127.4 nmol L^-1 ). In the adjusted mITT analysis, the primary TB score was significantly reduced in the intervention group at week 8 (-0.52, 95% CI -0.93, -0.10; P = 0.015) while the modified TB score was reduced at week 8 (-0.58, 95% CI -1.02, -0.14; P = 0.01) and 16 (-0.34, 95% CI -0.64, -0.03; P = 0.03). VitD₃ + PBA had no effect on longitudinal sputum-smear conversion (P = 0.98). Clinical adverse events were more common in the placebo group (24.3%) compared with the vitD₃ + PBA group (12.6%).

CONCLUSION

Daily supplementation with vitD₃ + PBA may ameliorate clinical TB symptoms and disease-specific complications, while the intervention had no effect on bacterial clearance in sputum.

Projected effectiveness of mandatory industrial fortification of wheat flour, milk, and edible oil with multiple micronutrients among Mongolian adults

Industrial fortification of wheat flour is a potentially effective strategy for addressing micronutrient deficiencies in Mongolia, given its ubiquitous consumption and centralized production. However, Mongolia has not mandated fortification of any foods except for salt with iodine. This study modeled the effectiveness and safety of mandatory industrial fortification of wheat flour alone and in combination with edible oil and milk in reducing the prevalence of multiple micronutrient intake deficiencies among healthy non-pregnant adults in Mongolia. Six days of diet records (3 summer, 3 winter) were collected from 320 urban and rural adults across the country and analyzed for food and nutrient consumption using a purpose-built food composition table, and the Intake Monitoring and Planning Program (IMAPP) was used to project the effects of fortification on summer and winter bioavailable micronutrient intake and intake deficiency under different fortification guidelines within population subgroups defined by urban or rural locality and sex. Projections showed that flour fortification would be effective in reducing intake deficiencies of thiamin and folate, while marginal benefits of fortification with iron and riboflavin would be smaller given these nutrients’ higher baseline consumption, and fortification with zinc, niacin, and vitamin B12 may be unnecessary. Fortification of flour, oil, and milk with vitamins A, D, and E at levels suggested by international guidelines would substantially reduce vitamin A intake deficiency and would increase vitamin D intake considerably, with the greatest benefits elicited by flour fortification and smaller benefits by additionally fortifying oil and milk. These results support mandatory industrial fortification of wheat flour, edible oil, and milk with iron, thiamin, riboflavin, folate, and vitamins A, D, and E in Mongolia. Considerations will be necessary to ensure the fortification of these nutrients is also effective for children, for whom the potential benefit of zinc, niacin, and vitamin B12 fortification should be assessed.

The association between vitamin D status and tuberculosis in children: A meta-analysis

BACKGROUND

Vitamin D deficiency (VDD) has been implicated in the pathogenesis of tuberculosis (TB), but most studies have not reported a significant association. We conducted a meta-analysis to explore the association between vitamin D status and TB in children.

METHODS

Web of Science, Ovid Medline, and EMBASE were searched for studies in English that discussed vitamin D status and TB in children before January 22, 2018.

RESULTS

From the 585 initially identified studies, we selected those that addressed an association between vitamin D status and TB according to our preselected inclusion criteria. Our meta-analysis included 10 studies. According to the random effects model, TB was significantly associated with VDD (ORs, 1.70; 95% CI, 1.20-2.42; P < .05) in children. Vitamin D levels were significantly lower in TB patients than in controls, with a mean difference d = -5.49 nmol/L (95% CI, -10.42 to -0.55; P < .05), indicating that VDD was significantly associated with TB (OR, 1.78; 95% CI, 1.30-2.44; P < .05) in children.

CONCLUSION

This study suggests that vitamin D levels are significantly lower in children with TB/latent TB infection than in controls. TB may contribute to VDD in children. Therefore, VDD may be associated with TB in children.

Vitamin D supplementation as a control program against latent tuberculosis infection in Korean high school students

The prevalence of latnet Mycobacterium tuberculosis infection (LTBI) in the first-grade high school students in South Korea was 2.1%, which was the lowest level at congregated settings in 2017. For LTBI cases refusing anti-tuberculosis (TB) medication or having poor compliance, additional support should be considered. Eight systematic reviews concluded that vitamin D (VD) deficiency is a risk factor for TB. While three of four South Korean adolescents were VD deficiency, VD supplementation could be a practical remedy to protect LTBI students of refusing anti-TB medication or having poor compliance.

Vitamin D status contributes to the antimicrobial activity of macrophages against Mycobacterium leprae

Background

The immune system depends on effector pathways to eliminate invading pathogens from the host in vivo. Macrophages (MΦ) of the innate immune system are armed with vitamin D-dependent antimicrobial responses to kill intracellular microbes. However, how the physiological levels of vitamin D during MΦ differentiation affect phenotype and function is unknown.

Methodology/principal

The human innate immune system consists of divergent MΦ subsets that serve distinct functions in vivo. Both IL-15 and IL-10 induce MΦ differentiation, but IL-15 induces primary human monocytes to differentiate into antimicrobial MΦ (IL-15 MΦ) that robustly express the vitamin D pathway. However, how vitamin D status alters IL-15 MΦ phenotype and function is unknown. In this study, we found that adding 25-hydroxyvitamin D3 (25D3) during the IL-15 induced differentiation of monocytes into MΦ increased the expression of the antimicrobial peptide cathelicidin, including both CAMP mRNA and the encoded protein cathelicidin in a dose-dependent manner. The presence of physiological levels of 25D during differentiation of IL-15 MΦ led to a significant vitamin D-dependent antimicrobial response against intracellular Mycobacterium leprae but did not change the phenotype or phagocytic function of these MΦ. These data suggest that activation of the vitamin D pathway during IL-15 MΦ differentiation augments the antimicrobial response against M. leprae infection.

Conclusions/significance

Our data demonstrates that the presence of vitamin D during MΦ differentiation bestows the capacity to mount an antimicrobial response against M. leprae.

A key function of MΦ is to recognize, phagocytose and mount an antimicrobial response against microbial pathogens to defend the host. In humans, monocytes are recruited to the site of infection and differentiate into MΦ upon the onset of microbial infection. The MΦ phenotype and function are determined by the cytokine profile of the microenvironment in which the monocyte enters. Additionally, vitamin D is known to trigger direct antimicrobial responses against invading pathogens in MΦ, but also disrupts the differentiation of immune subsets within the myeloid lineage. Therefore, we investigated whether vitamin D status during MΦ differentiation influenced either phenotype or function. Here, we found that the IL-15 MΦphenotype is sustained regardless of vitamin D status. In contrast, antimicrobial MΦ differentiated in the presence of vitamin D exhibited a robust expression of an antimicrobial peptide, relative to MΦ differentiated in the absence of vitamin D. The antimicrobial MΦ armed with cathelicidin prior to M. leprae challenge demonstrated a strong antimicrobial response against the invading pathogen. Our study reveals that the presence of sufficient levels of vitamin D prior to microbial infection contributes to effectively reduce the viability of the pathogen in MΦ.

Vitamin D and tuberculosis: where next?

Tuberculosis (TB) has troubled mankind for millennia, but current treatment strategies are long and complicated and the disease remains a major global health problem. The risk of Mycobacterium tuberculosis (Mtb) infection or progression of active TB disease is elevated in individuals with vitamin D deficiency. High-dose vitamin D was used to treat TB in the preantibiotic era, and in vitro experimental data show that vitamin D supports innate immune responses that restrict growth of Mtb. Several randomized controlled trials have tested whether adjunctive vitamin D supplementation enhances the clinical and microbiological response to standard antimicrobial chemotherapy for pulmonary TB. The effects have been modest at best, and attention is turning to the question of whether vitamin D supplementation might have a role in preventing acquisition or reactivation of latent Mtb infection. In this article, we describe the effects of vitamin D on host immune responses to Mtb in vitro and in vivo and review the results of clinical trials in the field. We also reflect on the findings of clinical trials of vitamin D supplementation for the prevention of acute respiratory tract infections, and discuss how these findings might influence the design of future trials to evaluate the role of vitamin D in the prevention and treatment of TB.

Vitamin D in pediatric age: consensus of the Italian Pediatric Society and the Italian Society of Preventive and Social Pediatrics, jointly with the Italian Federation of Pediatricians

Vitamin D plays a pivotal role in the regulation of calcium-phosphorus metabolism, particularly during pediatric age when nutritional rickets and impaired bone mass acquisition may occur.Besides its historical skeletal functions, in the last years it has been demonstrated that vitamin D directly or indirectly regulates up to 1250 genes, playing so-called extraskeletal actions. Indeed, recent data suggest a possible role of vitamin D in the pathogenesis of several pathological conditions, including infectious, allergic and autoimmune diseases. Thus, vitamin D deficiency may affect not only musculoskeletal health but also a potentially wide range of acute and chronic conditions. At present, the prevalence of vitamin D deficiency is high in Italian children and adolescents, and national recommendations on vitamin D supplementation during pediatric age are lacking. An expert panel of the Italian Society of Preventive and Social Pediatrics reviewed available literature focusing on randomized controlled trials of vitamin D supplementation to provide a practical approach to vitamin D supplementation for infants, children and adolescents.

Impact of Childhood Malnutrition on Host Defense and Infection

The global impact of childhood malnutrition is staggering. The synergism between malnutrition and infection contributes substantially to childhood morbidity and mortality. Anthropometric indicators of malnutrition are associated with the increased risk and severity of infections caused by many pathogens, including viruses, bacteria, protozoa, and helminths. Since childhood malnutrition commonly involves the inadequate intake of protein and calories, with superimposed micronutrient deficiencies, the causal factors involved in impaired host defense are usually not defined. This review focuses on literature related to impaired host defense and the risk of infection in primary childhood malnutrition. Particular attention is given to longitudinal and prospective cohort human studies and studies of experimental animal models that address causal, mechanistic relationships between malnutrition and host defense. Protein and micronutrient deficiencies impact the hematopoietic and lymphoid organs and compromise both innate and adaptive immune functions. Malnutrition-related changes in intestinal microbiota contribute to growth faltering and dysregulated inflammation and immune function. Although substantial progress has been made in understanding the malnutrition-infection synergism, critical gaps in our understanding remain. We highlight the need for mechanistic studies that can lead to targeted interventions to improve host defense and reduce the morbidity and mortality of infectious diseases in this vulnerable population.

Mechanisms of Defense against Intracellular Pathogens Mediated by Human Macrophages

The key question our work has sought to address has been, "What are the necessary and sufficient conditions that engender protection from intracellular pathogens in the human host?" The origins of this work derive from a long-standing interest in the mechanisms of protection against two such paradigmatic intracellular pathogens, Mycobacterium tuberculosis and Mycobacterium leprae, that have brilliantly adapted to the human host. It was obvious that these pathogens, which cause chronic diseases and persist in macrophages, must have acquired subtle strategies to resist host microbicidal mechanisms, yet since the vast majority of individuals infected with M. tuberculosis do not develop disease, there must be some potent human antimicrobial mechanisms. What follows is not a comprehensive review of the vast literature on the role of human macrophages in protection against infectious disease, but a summary of the research in our two laboratories with collaborators that we hope has contributed to some understanding of mechanisms of resistance and pathogenesis. While mouse models revealed some necessary conditions for protection, e.g., innate immunity, Th1 cells and their cytokines, and major histocompatibility complex class I-restricted T cells, here we emphasize multiple antimicrobial mechanisms that exist in human macrophages that differ from those of most experimental animals. Prominent here is the vitamin D-dependent antimicrobial pathway common to human macrophages activated by innate and acquired immune responses, mediated by antimicrobial peptides, e.g., cathelicidin, through an interleukin-15- and interleukin-32-dependent common pathway that is necessary for macrophage killing of M. tuberculosis in vitro.

Solar ultraviolet B exposure and global variation in tuberculosis incidence: an ecological analysis

Epidemiological evidence supports vitamin D deficiency as a risk factor for tuberculosis. Differences in solar ultraviolet B (UV-B) exposure, the major source of vitamin D, might therefore partially explain global variation in tuberculosis incidence.In a global country-based ecological study, we explored the correlation between vitamin D-proxies, such as solar UV-B exposure, and other relevant variables with tuberculosis incidence, averaged over the period 2004-2013.Across 154 countries, annual solar UV-B exposure was associated with tuberculosis incidence. Tuberculosis incidence in countries in the highest quartile of UV-B exposure was 78% (95% CI 57-88%, p<0.001) lower than that in countries in the lowest quartile, taking into account other vitamin D-proxies and covariates. Of the explained global variation in tuberculosis incidence, 6.3% could be attributed to variations in annual UV-B exposure. Exposure to UV-B had a similar, but weaker association with tuberculosis notification rates in the multilevel analysis with sub-national level data for large countries (highest versus lowest quartile 29% lower incidence; p=0.057).The potential preventive applications of vitamin D supplementation in high-risk groups for tuberculosis merits further investigation.

Vitamin D supplementation and growth in urban Mongol school children: Results from two randomized clinical trials

Background

Symptomatic vitamin D deficiency is associated with slowed growth in children. It is unknown whether vitamin D repletion in children with asymptomatic serum vitamin D deficiency can restore normal growth.

Objective

We tested the impact of vitamin D-supplementation on serum concentrations of 25-hydroxyvitamin D [25(OH)D] and short-term growth in Mongol children, with very low serum vitamin D levels in winter.

Design

We conducted two randomized, double-blind, placebo-controlled trials in urban school age children without clinical signs of rickets. The Supplementation Study was a 6-month intervention with an 800 IU vitamin D₃ supplement daily, compared with placebo, in 113 children aged 12–15 years. A second study, the Fortification Study, was a 7-week intervention with 710 ml of whole milk fortified with 300 IU vitamin D₃ daily, compared with unfortified milk, in 235 children aged 9–11 years.

Results

At winter baseline, children had low vitamin D levels, with a mean (±SD) serum 25-hydroxyvitamin D [25(OH)D] concentration of 7.3 (±3.9) ng/ml in the Supplementation Study and 7.5 (±3.8) ng/ml in the Fortification Study. The serum levels increased in both vitamin D groups—by 19.8 (±5.1) ng/ml in the Supplementation Study, and 19.7 (±6.1) ng/ml in the Fortification Study. Multivariable analysis showed a 0.9 (±0.3 SE) cm greater increase in height in the vitamin-D treated children, compared to placebo treated children, in the 6-month Supplementation Study (p = 0.003). Although the children in the 7-week Fortification Study intervention arm grew 0.2 (±0.1) cm more, on average, than placebo children this difference was not statistically significant (p = 0.2). There were no significant effects of vitamin D supplements on differences in changes in weight or body mass index in either trial. For the Fortification Study, girls gained more weight than boys while taking vitamin D 3 (p-value for interaction = 0.03), but sex was not an effect modifier of the relationship between vitamin D3 and change in either height or BMI in either trial.

Conclusions

Correcting vitamin D deficiency in children with very low serum vitamin D levels using 800 IU of vitamin D3 daily for six months increased growth, at least in the short-term, whereas, in a shorter trial of 300 IU of D fortified milk daily for 7 weeks did not.

Association of vitamin D deficiency, season of the year, and latent tuberculosis infection among household contacts

OBJECTIVES

Vitamin D (VD) enhances the immune response against Mycobacterium tuberculosis in vitro, and VD deficiency has been described in patients with active tuberculosis (TB). However, the role of hypovitaminosis D in the pathogenesis of early TB infection acquisition is unclear. We aimed to evaluate the association of VD deficiency, season of the year, and latent TB infection in household contacts (HHC), given that this is a potentially modifiable condition often related to nutritional deficiencies and lack of sun exposure.

METHODS

We prospectively enrolled new pulmonary TB cases (n = 107) and their HHC (n = 144) over a 2-year period in Santiago, Chile. We compared plasma 25-hydroxycholecalciferol (25OHD) levels and examined the influence of season, ethnic background, living conditions, and country of origin.

RESULTS

Over 77% of TB cases and 62.6% of HHC had VD deficiency (<20 ng/ml). Median 25OHD concentration was significantly lower in TB cases than in HHC (11.7 vs. 18.2 ng/ml, p<0.0001). Migrants HHC had lower 25OHD levels than non-migrants (14.6 vs. 19.0 ng/ml, p = 0.026), and a trend towards a higher burden of latent TB infection (52.9% vs. 35.2%, p = 0.066). Multivariate analysis found VD deficiency in HHC was strongly associated with being sampled in winter/spring (adOR 25.68, 95%CI 7.35-89.7), corresponding to the seasons with lowest solar radiation exposure. Spring enrollment-compared with other seasons-was the chief risk factor for latent TB infection in HHC (adOR 3.14, 95%CI 1.28-7.69).

CONCLUSIONS

Hypovitaminosis D was highly prevalent in TB cases and also in HHC. A marked seasonality was found for both VD levels and latent TB in HHC, with winter being the season with lowest VD levels and spring the season with the highest risk of latent TB infection.

Efficacy of vitamin D3 supplementation in reducing incidence of pulmonary tuberculosis and mortality among HIV-infected Tanzanian adults initiating antiretroviral therapy: study protocol for a randomized controlled trial

Background

HIV-infected adults initiating antiretroviral therapy (ART) in sub-Saharan Africa continue to experience high rates of morbidity and mortality during the initial months of treatment. Observational studies in high-income and resource-limited settings indicate that HIV-infected adults with low vitamin D levels may be at increased risk of mortality, HIV disease progression, and incidence of pulmonary tuberculosis (TB). As a result, vitamin D₃ supplementation may improve survival and treatment outcomes for HIV-infected adults initiating ART.

Methods/Design

The Trial of Vitamins-4 (ToV4) is an individually randomized, double-blind, placebo-controlled trial of vitamin D₃ (cholecalciferol) supplementation conducted among 4000 HIV-infected adults with low vitamin D levels [25-hydroxyvitamin D (25(OH)D) <30 ng/mL] initiating ART in Dar es Salaam, Tanzania. The two primary aims of the trial are to determine the effect of a vitamin D₃ supplementation regimen on incidence of (1) mortality and (2) pulmonary TB as compared to a matching placebo regimen. The primary safety outcome of the study is incident hypercalcemia. The investigational vitamin D₃ regimen consists of oral supplements containing 50,000 IU vitamin D₃ taken under direct observation at randomization and once a week for 3 weeks (four doses) followed by daily oral supplements containing 2000 IU vitamin D₃ taken at home from the fourth week until trial discharge at 1 year post ART initiation. Trial participants are followed up at weekly clinic visits during the first month of ART and at monthly clinic visits thereafter until trial discharge at 1 year post ART initiation. Secondary aims of the trial are to examine the effect of the vitamin D₃ regimen on CD4 T cell reconstitution, incidence of non-TB comorbidities, body mass index (BMI), depression and anxiety, physical activity, bone health, and immunologic biomarkers.

Discussion

The ToV4 will provide causal evidence on the effect of vitamin D₃ supplementation on incidence of pulmonary TB and mortality among HIV-infected Tanzanian adults initiating ART. The trial will also give insight to whether vitamin D₃ supplementation trials for the prevention of pulmonary TB should be pursued in HIV-uninfected populations.

Trial registration

ClinicalTrials.gov, NCT01798680. Registered on 21 February 2013.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-017-1819-5) contains supplementary material, which is available to authorized users.

Vitamin D deficiency and the risk of tuberculosis: a meta-analysis

BACKGROUND AND AIM

To conduct meta-analyses of all published studies on various aspects of association between vitamin D and tuberculosis (TB).

METHODS

PubMed and Web of Knowledge were searched for all properly controlled studies on vitamin D and TB. Pooled odds ratio, mean difference or standardized mean difference, and its corresponding 95% confidence interval were calculated with the Cochrane Review Manager 5.3.

RESULTS

A significantly lower vitamin D level was found in TB patients vs controls; vitamin D deficiency (VDD) was associated with an increased risk of TB, although such an association was lacking in the African population and in the human immunodeficiency virus-infected African population. A significantly lower vitamin D level was found in human immunodeficiency virus-TB-coinfected African patients receiving antiretroviral treatment who developed TB-associated immune reconstitution inflammatory syndrome vs those who did not develop TB-associated immune reconstitution inflammatory syndrome. VDD was associated with an increased risk of developing active TB in those subjects with latent TB infection and with an increased risk of tuberculin skin test conversion/TB infection conversion, and the trend toward a lower vitamin D level in active TB patients vs latent TB infection subjects did not reach statistical significance, indicating that VDD was more likely a risk factor than a consequence of TB. This concept was further strengthened by our result that anti-TB treatment did not affect vitamin D level in TB patients receiving the treatment.

CONCLUSION

Our analyses revealed an association between vitamin D and TB. VDD is more likely a risk factor for TB than its consequence. More studies are needed to determine whether vitamin D supplementation is beneficial to TB prevention and treatment.

Double-blind, placebo-controlled, 1:1 randomized Phase III clinical trial of Immunoxel honey lozenges as an adjunct immunotherapy in 269 patients with pulmonary tuberculosis

AIM

Safer and shorter antituberculosis treatment (ATT) regimens represent the unmet medical need.

PATIENTS & METHODS

The patients were randomly assigned into two arms: the first (n = 137) received once-daily sublingual honey lozenge formulated with botanical immunomodulator Immunoxel and the second (n = 132) received placebo lozenges along with conventional ATT. Immunoxel and placebo arms were demographically similar: 102 versus 106 had drug-susceptible TB; 28 versus 20 multidrug-resistant TB (MDR-TB); 7 versus 7 extensively drug-resistant TB (XDR-TB); and 22 versus 20 TB-HIV. The primary end point was sputum smear conversion.

RESULTS

After 1 month 87 out 132 (65.9%) of Immunoxel recipients became sputum smear negative, whereas 32 out of 127 (25.2%) in placebo group had converted (p < 0.0001). Sputum clearance produced by Immunoxel was equally effective across all forms of TB. In the immunotherapy arm the average weight gain was 2 kg, but placebo recipients gained only 0.6 kg. Immunoxel reduced TB-associated inflammation as evidenced by defervescence and normalization of elevated leukocyte counts and erythrocyte sedimentation rate. No adverse effects were seen at any time. The liver function tests indicate that ATT-caused hepatotoxicity was counteracted by Immunoxel. These results are in agreement with prior 20 trials of Immunoxel conducted over the past 17 years.

CONCLUSION

Immunoxel is affordable, safe, effective, fast-acting, commercially available immunotherapeutic intervention to supplement conventional TB chemotherapy. Clinicaltrials.gov ID: NCT01061593.

Vitamin D supplementation for preventing infections in children under five years of age

BACKGROUND

Vitamin D is a micronutrient important for bone growth and immune function. Deficiency can lead to rickets and has been linked to various infections, including respiratory infections. The evidence on the effects of supplementation on infections in children has not been assessed systematically.

OBJECTIVES

To evaluate the role of vitamin D supplementation in preventing pneumonia, tuberculosis (TB), diarrhoea, and malaria in children under five years of age. This includes high-, middle-, and low-income countries.

SEARCH METHODS

We searched the Cochrane Infectious Diseases Group Specialized Register, the Cochrane Central Register of Controlled Trials (CENTRAL), the Cochrane Library, MEDLINE, EMBASE, LILACS, the WHO International Clinical Trials Registry Platform (ICTRP; http://www.who.int/ictrp/en/) , ClinicalTrials.gov and the ISRCTN registry (http://www.isrctn.com/) up to 16 June 2016.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) that evaluated preventive supplementation of vitamin D (versus placebo or no intervention) in children under five years of age.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the titles and abstracts, extracted the data, and assessed the risk of bias of included trials.

MAIN RESULTS

Four trials met the inclusion criteria, with a total of 3198 children under five years of age, and were conducted in Afghanistan, Spain, and the USA. Prevalence of vitamin D deficiency varied widely in these populations (range: 73.1% in Afghanistan, 10 to 12% in USA, and 6.2% in Spain). The included trials evaluated mortality (two trials), pneumonia incidence (two trials), diarrhoea incidence (two trials), hospitalization (two trials), and mean serum vitamin D concentrations (four trials).We do not know whether vitamin D supplementation impacts on all-cause mortality because this outcome was underpowered due to few events (risk ratio (RR) 1.43, 95% confidence interval (CI) 0.54 to 3.74; one trial, 3046 participants, low quality evidence).For pneumonia, episodes of 'radiologically confirmed' first or only episode of pneumonia were little different in the supplemented and unsupplemented group (Rate Ratio: 1.06, 95% confidence interval (CI) 0.89 to 1.26; two trials, 3134 participants, moderate quality evidence), and similarly for children with confirmed or unconfirmed pneumonia (RR 0.95, 95% CI 0.87 to 1.04; one trial, 3046 participants). In these two trials there were no obvious differences between supplemented and unsupplemented children regarding episodes of diarrhoea.In the single large trial from Afghanistan, the trial authors reported that vitamin D supplementation was associated with an increase in repeat episodes of pneumonia confirmed by chest radiograph (RR 1.69, 95% CI 1.28 to 2.21; one trial, 3046 participants), but not reflected in the outcome of confirmed or unconfirmed pneumonia (RR 1.06, 95% CI 1.00 to 1.13; one trial, 3046 participants).For hospital admission measured in one small trial, there was no difference detected (RR 0.86, 95% CI 0.20 to 3.62; one trial, 88 participants; very low quality evidence).The mean serum vitamin D concentrations were higher in supplemented compared to unsupplemented children at the end of supplementation (MD 7.72 ng/mL, 95% CI 0.50 to 14.93; four trials, 266 participants, low quality evidence). These results were driven primarily by two smaller trials with large magnitudes of effect. In the other two bigger trials, serum vitamin D concentrations were elevated in the intervention group for most of the trial duration but not at the end of supplementation. This may be due to time elapsed at measurement from the last dose, incomplete compliance, or increased need of vitamin D with infant age.We did not find any trial that reported on the incidence of TB, malaria or febrile illness, duration of pneumonia, duration of diarrhoea, severity of infection, and cause-specific mortality (due to TB, diarrhoea, or malaria).

AUTHORS' CONCLUSIONS

Evidence from one large trial did not demonstrate benefit of vitamin D supplementation on the incidence of pneumonia or diarrhoea in children under five years. To our knowledge, trials that evaluated supplementation for preventing other infections, including TB and malaria, have not been performed.

Vitamin D and airway infections: a European perspective

Vitamin D has immuno-modulatory properties, and deficient levels of circulating 25-hydroxyvitamin D (<30 nmol/l) may contribute to increased risk of infectious illnesses. This narrative review summarises data on vitamin D status in Europe and updates results of randomised controlled trials (RCTs) regarding vitamin D and airway infections such as tuberculosis (TB) and acute upper respiratory tract infection. In Europe, the prevalence of vitamin D deficiency is up to 37% in the general population and up to 80% in nursing home residents and non-European immigrants. Half of TB patients have a migration background. While results of RCTs do not support the concept of beneficial adjunctive effects of vitamin D supplements in anti-TB treatment [odds ratio (OR) = 0.86; 95% CI 0.62-1.19], the few published RCTs on the prophylaxis of TB suggest some protective vitamin D effects in individuals with deficient circulating 25-hydroxyvitamin D levels. Regarding acute respiratory tract infection, RCTs indicate a significant risk reduction by vitamin D supplements [OR = 0.65; 95% confidence interval (CI) 0.50-0.85]. There is evidence that daily administration is more effective than high-dose bolus administration [OR = 0.48 (95% CI 0.30-0.77) vs. OR = 0.87 (95% CI 0.67-1.14)] and that individuals with deficient or insufficient (30-50 nmol/l) circulating 25-hydroxyvitamin D levels benefit most. Several vitamin D effects on innate immunity may explain these protective effects. In summary, there is possible evidence from RCTs for protective vitamin D effects on TB and likely evidence for protective effects on acute airway infection. Since vitamin D deficiency is prevalent in Europe, especially in institutionalised individuals and non-European immigrants, daily oral vitamin D intake, e.g. 1000 international units, is an inexpensive measure to ensure adequate vitamin D status in individuals at risk.

The seasonality of slipped upper femoral epiphysis--meta-analysis: a possible association with vitamin D

We performed a meta-analysis of studies evaluating the seasonality of slipped upper femoral epiphysis (SUFE). In addition we compared the monthly incidences of SUFE at latitudes greater than 40° with the established serum 25-hydroxyvitamin levels for children resident at a comparative latitude. In total 11 relevant studies were identified, involving 7451 cases of SUFE. There was significant variation in the month of onset of SUFE. The degree of variability increased with increasing latitude. The modal month of symptomatic onset was dependent upon latitude. At latitudes greater than 40°, the most common month of onset was August. At latitudes between 20° and 40°, this was earlier in the calendar year, around April. The seasonal variability was statistically significant (p<0.0001 and p<0.005 for latitudes >40° and 20°-40° respectively). The pattern of monthly fluctuation in onset of SUFE very closely mirrored the monthly pattern of variation for serum 25-hydroxyvitamin D3. There was a very strong positive correlation (Spearman rank rho = + 0.8, p = 0.001). There is a monthly variation in incidence of SUFE. The degree of variability increases with increasing latitude. There may be an association with vitamin D. We hypothesise that elevated serum 25-hydroxyvitamin D3 accelerates growth thus rendering the growth plate vulnerable to slippage in analogous manner to the pubertal growth spurt.

Vitamin D and respiratory tract infections in childhood

BACKGROUND

Respiratory tract infections (RTIs) remain among of the most important causes of morbidity and mortality among children. Several studies have associated vitamin D deficiency with an increased risk of RTIs, and vitamin D supplementation has been proposed as a possible preventive measure against RTIs in children. The main aim of this review is to summarize the current evidence from the literature about the link between vitamin D and RTIs in children.

DISCUSSION

Several recent studies have shown that vitamin D has different immunomodulatory properties associated with the risk of RTIs in childhood. In this regard, it is very important to understand the definition of deficiency and insufficiency of vitamin D and when and how to treat this condition. Unfortunately, there is no consensus, although a level of at least 10 ng/mL 25-hydroxycholecalciferol (25[OH]D) is thought to be necessary to promote bone mineralization and calcium homeostasis, and a concentration between 20 ng/mL and 50 ng/mL is considered adequate to provide an immunomodulatory effect. Available data support a role for vitamin D deficiency in the risk of pediatric tuberculosis, recurrent acute otitis media, and severe bronchiolitis, whereas further studies are needed to confirm an association in children with recurrent pharyngotonsillitis, acute rhinosinusitis and community-acquired pneumonia.

CONCLUSIONS

Maintenance of adequate vitamin D status may be an effective and inexpensive prophylactic method against some RTIs, but the supplementation regimen has not been clearly defined. Further clinical trials are needed to determine the 25(OH)D concentrations associated with an increased risk of RTIs and optimal vitamin D supplementation regimen according to the type of RTI while also taking into consideration vitamin D receptor polymorphisms.

Vitamin D Status in South Korean Military Personnel with Acute Eosinophilic Pneumonia: A Pilot Study

Background

A relationship between low vitamin D levels and the development or outcomes of respiratory diseases has been identified. However, there is no data on the vitamin D status in patients with acute eosinophilic pneumonia (AEP). We evaluated the vitamin D status in patients with AEP among South Korean military personnel.

Methods

We prospectively compared the serum levels of total 25-hydroxyvitamin D [25(OH)D], 25(OH)D3, and 25(OH)D2 among patients with AEP, pulmonary tuberculosis (PTB), and community-acquired pneumonia (CAP).

Results

In total, 65 patients with respiratory diseases, including AEP (n=24), PTB (n=19), and CAP (n=22), were identified. Of the 24 patients with AEP, 2 (8%) had deficient total 25(OH)D levels (<10 ng/mL), 17 (71%) had insufficient total 25(OH)D levels (≥10 to <30 ng/mL), and only 5 (21%) had sufficient total 25(OH)D levels (≥30 to <100 ng/mL). The difference in the total 25(OH)D levels among patients with AEP, PTB, and CAP was not statistically significant (p=0.230). The median levels of total 25(OH)D, 25(OH)D3, and 25(OH)D2 were 22.84, 22.84, and 0.00 ng/mL, respectively, and no differences in the 25(OH)D level were present among patients with AEP, PTB, and CAP with the exception of the total 25(OH)D level between patients with AEP and PTB (p=0.042).

Conclusion

We have shown that low vitamin D levels are frequently found in patients with AEP and are comparable with those in patients with PTB and CAP.