Vitamin D deficiency and severity of pneumonia in Indonesian children

Vitamin D and Respiratory Diseases : Based on 11th Dr. I. C. Verma Excellence in Research Award for Young Pediatricians Delivered as Oration on 15th Oct. 2023

The significance of Vitamin D has been appreciated beyond bone health and calcium metabolism. The importance of Vitamin D in respiratory health has been recognized due to its immunomodulatory and anti-microbial properties. The hypothesis is that Vitamin D could have a significant role in the pathogenesis of respiratory diseases and may represent a novel preventive and therapeutic strategy. Furthermore, enumerable observational studies established the association of Vitamin D deficiency with respiratory diseases such as asthma, bronchiolitis, pneumonia, tuberculosis, etc. However, experimental studies have not shown the encouraging results. This brief review will summarize and discuss the synthesis and metabolism of Vitamin D, the prevalence of Vitamin D deficiency in children, its role in the pathogenesis of various childhood respiratory diseases, and an overview of the therapeutic trials assessing the role of Vitamin D supplementation in childhood respiratory diseases.

Immunomodulatory Effects of Vitamin D in Respiratory Tract Infections and COVID-19 in Children

Acute respiratory tract infections (ARTIs) are one of the main reasons that the pediatric population goes to the doctor. The connection between ARTI and vitamin D (VD) is currently debated by the medical community, and so far, there has been little agreement with regard to the ideal level of 25(OH)D concentration that would provide protection for the respiratory tract, or the effectiveness of its administration in the treatment of respiratory infections. The purpose of this literature review was to bring attention to the immunomodulatory and antiviral function of vitamin D and its relation to the respiratory system by examining the main ARTIs, including SARS-CoV-2. The latter has affected the pediatric population in different ways, from asymptomatic patients to severe forms with multisystem inflammatory syndrome in children (MIS-C). Although there are not much clinical data on the SARS-CoV-2 disease in the pediatric population worldwide, we tried to find out whether there is a connection between the severity of this disease, other ARTIs, and vitamin D supplementation. We also aimed to find out if 25OHD deficiency had an adverse effect on the evolution of the disease and the recovery period in the case of younger patients affected by COVID-19. For this literature review, the PICO framework was selected as the methodological approach. Our results demonstrated many methods by which this vitamin may lower the risk of ARTI with regard to the COVID-19 infection. Despite these significant advancements, more research is needed to support the idea that 25(OH)D concentration can influence the evolution of respiratory tract infections in children.

Vitamin D as an adjunct to antibiotics for the treatment of acute childhood pneumonia

BACKGROUND

Children with acute pneumonia may be vitamin D deficient. Clinical trials have found that prophylactic vitamin D supplementation decreases children's risk of developing pneumonia. Data on the therapeutic effects of vitamin D in acute childhood pneumonia are limited. This is an update of a Cochrane Review first published in 2018.

OBJECTIVES

To evaluate the efficacy and safety of vitamin D supplementation as an adjunct to antibiotics for the treatment of acute childhood pneumonia.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, and two trial registries on 28 December 2021. We applied no language restrictions.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared vitamin D supplementation with placebo in children (aged one month to five years) hospitalised with acute community-acquired pneumonia, as defined by the World Health Organization (WHO) acute respiratory infection guidelines. For this update, we reappraised eligible trials according to research integrity criteria, excluding RCTs published from April 2018 that were not prospectively registered in a trials registry according to WHO or Clinical Trials Registry - India (CTRI) guidelines (it was not mandatory to register clinical trials in India before April 2018).

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion and extracted data. For dichotomous data, we extracted the number of participants experiencing the outcome and the total number of participants in each treatment group. For continuous data, we used the arithmetic mean and standard deviation (SD) for each treatment group together with number of participants in each group. We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

In this update, we included three new trials involving 468 children, bringing the total number of trials to seven, with 1601 children (631 with pneumonia and 970 with severe or very severe pneumonia). We categorised three previously included studies and three new studies as 'awaiting classification' based on the research integrity screen. Five trials used a single bolus dose of vitamin D (300,000 IU in one trial and 100,000 IU in four trials) at the onset of illness or within 24 hours of hospital admission; one used a daily dose of oral vitamin D (1000 IU for children aged up to one year and 2000 IU for children aged over one year) for five days; and one used variable doses (on day 1, 20,000 IU in children younger than six months, 50,000 IU in children aged six to 12 months, and 100,000 IU in children aged 13 to 59 months; followed by 10,000 IU/day for four days or until discharge). Three trials performed microbiological diagnosis of pneumonia, radiological diagnosis of pneumonia, or both. Vitamin D probably has little or no effect on the time to resolution of acute illness (mean difference (MD) -1.28 hours, 95% confidence interval (CI) -5.47 to 2.91; 5 trials, 1188 children; moderate-certainty evidence). We do not know if vitamin D has an effect on the duration of hospitalisation (MD 4.96 hours, 95% CI -8.28 to 18.21; 5 trials, 1023 children; very low-certainty evidence). We do not know if vitamin D has an effect on mortality rate (risk ratio (RR) 0.69, 95% CI 0.44 to 1.07; 3 trials, 584 children; low-certainty evidence). The trials reported no major adverse events. According to GRADE criteria, the evidence was of very low-to-moderate certainty for all outcomes, owing to serious trial limitations, inconsistency, indirectness, and imprecision. Three trials received funding: one from the New Zealand Aid Corporation, one from an institutional grant, and one from multigovernment organisations (Bangladesh, Sweden, and UK). The remaining four trials were unfunded.

AUTHORS' CONCLUSIONS

Based on the available evidence, we are uncertain whether vitamin D supplementation has important effects on outcomes of acute pneumonia when used as an adjunct to antibiotics. The trials reported no major adverse events. Uncertainty in the evidence is due to imprecision, risk of bias, inconsistency, and indirectness.

Perspective: School Meal Programs Require Higher Vitamin D Fortification Levels in Milk Products and Plant-Based Alternatives-Evidence from the National Health and Nutrition Examination Surveys (NHANES 2001-2018)

Poor vitamin D status impairs bone growth and immune defense in school-aged children and adolescents, particularly in minorities. Vitamin D insufficiency/deficiency increases the risk of acute viral respiratory infection, underscoring the need for adequate vitamin D intakes during school sessions when viral exposure may be greatest. We studied available vitamin D-related survey data and published findings based on NHANES (2001-2018) to assess the dependency of vitamin D status {25-hydroxyvitamin D [25(OH)D]; in nmol/L} on vitamin D intake (μg/d) in elementary school-aged children (4-8 y), middle school children (9-13 y), and high school adolescents (14-18 y). We sought evidence supporting the need for school programs to facilitate vitamin D adequacy. Usual vitamin D intakes from food and beverages by children/adolescents (NHANES 2015-2018) examined at the 50th percentile intake by race/ethnicity (non-Hispanic White, non-Hispanic Black, Hispanic) showed all age groups consumed less than half of the Estimated Average Requirement (EAR) for vitamin D (10 μg/d), independent of race/ethnicity. NHANES (2001-2010) analyses show evidence of lower vitamin D status in school-aged children that is linked to lower intakes of fortified milk varying over race/ethnicity and age. Adolescents had lower vitamin D status and milk intake than younger children. A total of 22-44% of vitamin D intakes occurred away from home, with larger percentages of total intakes at breakfast and lunch, at times consistent with school meals. Ever-present inadequate vitamin D intakes with a large percentage consumed away from home together with well-established benefits to growth, bone, and immune defense from enriched vitamin D-fortified milk in school intervention trials provide strong justification to require enriched vitamin D-fortified foods in school meals. An easy to implement plan for improving vitamin D intakes is possible through the FDA's amendment allowing higher vitamin D fortification levels of dairy and plant-based milk alternatives that could increase vitamin D intakes beyond the EAR with just 2 daily servings.

The Role of Vitamin D in Supporting Health in the COVID-19 Era

The genomic activity of vitamin D is associated with metabolic effects, and the hormone has a strong impact on several physiological functions and, therefore, on health. Among its renowned functions, vitamin D is an immunomodulator and a molecule with an anti-inflammatory effect, and, recently, it has been much studied in relation to its response against viral infections, especially against COVID-19. This review aims to take stock of the correlation studies between vitamin D deficiency and increased risks of severe COVID-19 disease and, similarly, between vitamin D deficiency and acute respiratory distress syndrome. Based on this evidence, supplementation with vitamin D has been tested in clinical trials, and the results are discussed. Finally, this study includes a biochemical analysis on the effects of vitamin D in the body's defense mechanisms against viral infection. In particular, the antioxidant and anti-inflammatory functions are considered in relation to energy metabolism, and the potential, beneficial effect of vitamin D in COVID-19 is described, with discussion of its influence on different biochemical pathways. The proposed, broader view of vitamin D activity could support a better-integrated approach in supplementation strategies against severe COVID-19, which could be valuable in a near future of living with an infection becoming endemic.

Prevalence of hypoxaemia in children with pneumonia in low-income and middle-income countries: a systematic review and meta-analysis

Background

Pneumonia accounts for around 15% of all deaths of children younger than 5 years globally. Most happen in resource-constrained settings and are potentially preventable. Hypoxaemia is one of the strongest predictors of these deaths. We present an updated estimate of hypoxaemia prevalence among children with pneumonia in low-income and middle-income countries.

Methods

We conducted a systematic review using the following key concepts “children under five years of age” AND “pneumonia” AND “hypoxaemia” AND “low- and middle-income countries” by searching in 11 bibliographic databases and citation indices. We included all articles published between Nov 1, 2008, and Oct 8, 2021, based on observational studies and control arms of randomised and non-randomised controlled trials. We excluded protocol papers, articles reporting hypoxaemia prevalence based on less than 100 pneumonia cases, and articles published before 2008 from the review. Quality appraisal was done with the Joanna Briggs Institute tools. We reported pooled prevalence of hypoxaemia (SpO₂ <90%) by classification of clinical severity and by clinical settings by use of the random-effects meta-analysis models. We combined our estimate of the pooled prevalence of pneumonia with a previously published estimate of the number of children admitted to hospital due to pneumonia annually to calculate the total annual number of children admitted to hospital with hypoxaemic pneumonia.

Findings

We identified 2825 unique records from the databases, of which 57 studies met the eligibility criteria: 26 from Africa, 23 from Asia, five from South America, and four from multiple continents. The prevalence of hypoxaemia was 31% (95% CI 26–36; 101 775 children) among all children with WHO-classified pneumonia, 41% (33–49; 30 483 children) among those with very severe or severe pneumonia, and 8% (3–16; 2395 children) among those with non-severe pneumonia. The prevalence was much higher in studies conducted in emergency and inpatient settings than in studies conducted in outpatient settings. In 2019, we estimated that over 7 million children (95% CI 5–8 million) were admitted to hospital with hypoxaemic pneumonia. The studies included in this systematic review had high τ² (ie, 0·17), indicating a high level of heterogeneity between studies, and a high I² value (ie, 99·6%), indicating that the heterogeneity was not due to chance. This study is registered with PROSPERO, CRD42019126207.

Interpretation

The high prevalence of hypoxaemia among children with severe pneumonia, particularly among children who have been admitted to hospital, emphasises the importance of overall oxygen security within the health systems of low-income and middle-income countries, particularly in the context of the COVID-19 pandemic. Even among children with non-severe pneumonia that is managed in outpatient and community settings, the high prevalence emphasises the importance of rapid identification of hypoxaemia at the first point of contact and referral for appropriate oxygen therapy.

Funding

UK National Institute for Health Research (Global Health Research Unit on Respiratory Health [RESPIRE]; 16/136/109).