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

Vitamin D Improves Klebsiella-Induced Severe Pneumonia in Rats by Regulating Intestinal Microbiota

Background

In the context of progressively uncontrolled drug resistance of bacteria, the difficulty of treating Klebsiella (KP)-induced pneumonia increases. Searching for drugs other than antibiotics has become an urgent task. Vitamin D (VD), meanwhile, is shown to be capable of treating pneumonia. Therefore, we aimed to explore the effects and mechanisms of VD on KP-infected rats.

Methods

Male Sprague Dawley rats were divided into the Control, VD, KP and KP+VD groups. A rat pneumonia model was induced using an intratracheal drop of 2.4×108 CFU/mL KP. VD treatment was performed by gavage using 5 μg/kg. Subsequently, the survival of the rats was recorded, and the lungs, bronchoalveolar lavage fluid, and feces of the rats were collected 4 days after KP infection. Next, the water content of lung tissues was measured by the wet-to-dry weight ratio. Histopathological changes of lung tissues were observed by Hematoxylin and Eosin staining and the levels of inflammatory factors (TNF-α, IL-1β, MCP1) were detected using ELISA. The feces of rats in each group were also subjected to 16S rDNA gene analysis of intestinal microbiota.

Results

Compared with the KP group, the KP+VD group showed a significant increase in survival, a significant decrease in water content and bacterial counts in the lungs, a significant improvement in lung injury, and a significant decline in the levels of TNF-α, IL-1β, and MCP1. According to the 16S rDNA sequencing, VD altered the structure of the intestinal bacterial community in the KP-infected rats and made the species richness similar to that of healthy rats. Additionally, the abundance of Anaeroglobus was significantly increased in the KP+VD group.

Conclusion

VD modulates intestinal microbiota to increase the resistance of rats to pneumonia caused by Klebsiella infection.

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.

Prevalence of vitamin D deficiency and associated risk of all-cause and cause-specific mortality among middle-aged and older adults in the United States

Introduction

The prevalence of vitamin D deficiency varied among populations and regions worldwide. In addition, the association between vitamin D deficiency and health outcomes remained controversial. Our study aimed to investigate the prevalence of vitamin D deficiency and its association with mortality risk among non-institutional middle-aged and older adults in the United States.

Method

The study population included 11,119 adult participants aged between 50 and 79 years in the 2007-2016 National Health and Nutrition Examination Survey (NHANES). Vitamin D status was divided as ≤ 30 (severely deficient), 30.1-50 (moderately deficient), 50.1-75 (insufficient), 75.1-100 (sufficient), and > 100 nmol/L (very sufficient). NHANES data were linked to National Death Index to ascertain the survival status and cause of death.

Results

The population aged 61.5 years (survey-weighted) and 47.9% were men. Among them, 4.6% were severely vitamin D deficient, 15.2% moderately deficient, and 33.6% insufficient. Individuals with higher vitamin D levels tended to be female, older, white people, non-smoker, non-single, more educated, with higher family income, and lower body mass index. During a median follow-up of 97.0 months, a total of 1,585 participants died (15.9 per 10,000 person-months). The crude analysis showed that vitamin D deficiency, but not vitamin D insufficiency, correlated to higher all-cause mortality risk. The association remained similar after adjusting for potential confounders, showing that vitamin D deficiency (HR: 1.38, 95% CI 1.15-1.66), but not vitamin D insufficiency (HR: 1.03, 95% CI 0.88-1.20), correlated to higher all-cause mortality risk. In addition, we showed that vitamin D deficiency was an independent risk factor for death from pneumonia (HR: 3.82, 95% CI 1.14-12.86) but not from cardiovascular diseases, cancer, or cerebrovascular diseases.

Conclusion

In summary, among middle-aged and older adults in the United States, nearly 20% were vitamin D deficient. Vitamin D deficiency, but not vitamin D insufficiency, correlated to increased mortality risk.