Vitamin D status in children with COVID-19: does it affect the development of long COVID and its symptoms?
Vita Perestiuk, Tetyana Kosovska, O.M. Dyvoniak, L.A. Volianska, Oksana Boyarchuk
Abstract
Introduction Long COVID is characterized by diverse symptoms persisting after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Given the immunomodulatory and neuroprotective properties of vitamin D, understanding its role in long COVID symptoms is of growing interest. This study aimed to determine vitamin D status in children with COVID-19 and assess its impact on the clinical course of disease and long COVID development. Methods A prospective cohort study included hospitalized children with confirmed COVID-19, aged 1 month to 18 years, diagnosed between September 2022 and March 2024. Serum 25-hydroxyvitamin D (25(OH)D) concentrations were measured upon hospital admission, and follow-up was done to identify long COVID symptoms. Results In total, 162 hospitalized patients with COVID-19 were examined. Vitamin D deficiency was determined in 8.0%, insufficiency in 25.3%, and optimal levels in 66.7% of children with COVID-19. Vitamin D deficiency/insufficiency was observed in 73% of children over 6 years and 21.6% of children under 6 years of age. Comorbid conditions were 1.4 times more frequent in children with vitamin D insufficiency, with undernutrition and obesity playing the most significant roles ( p = 0.0023, p = 0.0245, respectively). Serum 25(OH)D concentration depends on COVID-19 severity ( p = 0.0405) and children with vitamin D deficiency/insufficiency had a longer hospital stay (4 vs. 3 days, p = 0.0197). The vitamin D status affected the median levels of neutrophils, lymphocytes, their ratio, prothrombin time, fibrinogen levels, and the frequency of increased immunoglobulins M and E levels. Among 134 children who agreed to follow up, 56 (41.8%) experienced long COVID symptoms, while 78 (58.2%) recovered fully. Long COVID was frequently observed in children with vitamin D deficiency/insufficiency ( p = 0.0331). The odds of developing long COVID were 2.2 times higher ( p = 0.0346) in children with vitamin D deficiency/insufficiency compared to those with optimal levels. Children with vitamin D deficiency/insufficiency more often exhibited neurological (80% vs. 41.9%, p = 0.0040) and musculoskeletal symptoms (16% vs. 0%, p = 0.0208). Conclusion The 25(OH)D concentrations in children with COVID-19 depended on their age. Comorbid conditions affect the vitamin D status in children with COVID-19. Vitamin D influenced the COVID-19 severity and duration of hospitalization. There was an increased risk of developing long COVID in children with vitamin D deficiency/insufficiency, and its impact on the development of neurological symptoms associated with long COVID was established.