Background We sought to evaluate the association between vitamin D deficiency and severity of COVID-19 infection. Methods Multiple databases from January 1st, 2019 to December 3^rd, 2020 were searched for observational studies evaluating the association between vitamin D deficiency and severity of COVID-19 infection. Independent reviewers selected studies and extracted data for the review. The main outcomes of interest were mortality, hospital admission, length of hospital stay and intensive care unit admission. Results 17 observational studies with 2,756 patients were included in the analyses. Vitamin D deficiency was associated with significantly higher mortality (OR: 2.47, 95% CI: 1.50 to 4.05; 12 studies; HR: 4.11, 95% CI: 2.40 to 7.04; 3 studies), higher rates of hospital admissions (OR: 2.18, 95% CI: 1.48 to 3.21; 3 studies); and longer hospital stays (0.52 days; 95% CI: 0.25 to 0.80; 2 studies) as compared to non-vitamin D deficient status. Subgroup analyses based on different cut offs for defining vitamin D deficiency, study geographic locations and latitude also showed similar trends. Conclusions Vitamin D deficiency is associated with greater severity of COVID-19 infection. Further studies are warranted to determine if vitamin D supplementation can decrease severity of COVID-19.

This mini-review aims to briefly summarize the pathophysiology of childhood obesity, type 2 diabetes mellitus (T2DM), and cardiovascular disease (CVD) risk in children and adolescents. Recent data on efficacy of lifestyle interventions, medications, and metabolic surgery for obesity, T2DM, and CVD risk factors are also reviewed. We conducted a PubMed search of English-language original and review articles relevant to childhood obesity, T2DM, and CVD risk factors, and biomarkers in children with an emphasis on recent publications. Childhood obesity arises from an intricate interaction between genetic, physiologic, environmental, and socioeconomic factors. The rise in the prevalence of childhood obesity is associated with the development of comorbidities including T2DM and CVD at an early age. A multipronged approach is central to the detection, monitoring, and management of childhood obesity and associated adverse metabolic consequences.

Context: Spexin is a novel peptide that is implicated in obesity and related energy homeostasis in animals and adult humans. Little is known about its role in children. Objective: The aim of the current study was to determine the potential role of Spexin in obese children and explore its relationships with various cardiometabolic risk factors. Design and Participants: This was a cross-sectional study composed of 69 children (51 obese and 18 normal weight; age 15.3 ± 0.26 y). Outcome Measures: Spexin was measured using a specific enzyme-linked immunosorbent assay. Leptin, total and high-molecular-weight adiponectin, IL-6, high-sensitivity C-reactive protein, glucose, and insulin were also measured. Mann-Whitney U test, Pearson and Spearman rank correlations, logistic regression, and cluster analysis were used for the analysis and interpretation of the data. Results: Spexin levels were significantly lower in obese vs normal-weight children, median(IQR) (0.33 ng/mL [0.27–0.44] vs 0.42 ng/mL [0.33–0.55]; P = .024), but did not correlate with other adipokines and/or insulin and glucose levels. Ordinal categorical variables of Spexin showed a strictly reverse association of obesity with the level of Spexin. Cluster analysis of Spexin and body mass index z score resulted in splitting the participants into normal-weight and obese-weight groups with high accuracy. Conclusions: Lower circulating levels of Spexin in obese children compared with their normal-weight counterparts and the ability to discriminate obese and normal-weight groups based on Spexin concentration enabled us to suggest a potential role for this novel peptide in childhood obesity. The clinical significance of these findings needs additional investigation. Spexin, a novel peptide recently implicated in energy homeostasis, is reduced in obese vs. lean children. The ability of Spexin to accurately discriminate obese and lean children suggests a crucial role for it in childhood obesity.

Background/Aims: Vitamin D deficiency is highly prevalent in obese children, and obese children tend to respond poorly to vitamin D supplementation. The objective of the study was to compare the response to vitamin D₃ supplementation (2,000 IU once daily for 12 weeks) between obese and non-obese Caucasian adolescents. Methods: The study design was open label non-randomized. It was carried out at a single center. Eighteen obese adolescents (aged 12–18 years) and the same number of age-, gender- and season-matched non-obese adolescents received vitamin D₃ (2,000 IU/day) orally for 12 weeks. Total serum 25-hydroxyvitamin D [25(OH)D], parathyroid hormone, calcium and phosphorus were measured at baseline and at the end of the 12-week period. Results: The mean baseline 25(OH)D level was higher in the non-obese compared to the obese subjects (mean 28.9 vs. 25.2 ng/ml; p = 0.029). The increment in 25(OH)D levels following vitamin D supplementation was significantly lower in the obese adolescents (mean change 5.8 vs. 9.8 ng/ml; p = 0.019). Conclusions: Higher doses of vitamin D are required to treat vitamin D deficiency in obese adolescents compared to their non-obese peers.