Low Vitamin D Levels Are Associated With Long COVID Syndrome in COVID-19 Survivors

• Published in: The journal of clinical endocrinology and metabolism Vol. 108; no. 10; pp. e1106 - e1116
• Main Authors: di Filippo, Luigi, Frara, Stefano, Nannipieri, Fabrizio, Cotellessa, Alice, Locatelli, Massimo, Rovere Querini, Patrizia, Giustina, Andrea
• Format: Journal Article
• Language: English
• Published: US Oxford University Press 18.09.2023
• Subjects: Bone turnover; Calcium metabolism; Clinical; Clinical trials; Cognition; Comorbidity; Complications; COVID-19; COVID-19 - complications; COVID-19 - epidemiology; Dietary supplements; Humans; Long COVID; Post-Acute COVID-19 Syndrome; Retrospective Studies; Survivors; Vitamin D; Vitamin D Deficiency - complications; Vitamin D Deficiency - diagnosis; Vitamin D Deficiency - epidemiology; Vitamin deficiency; Vitamins; COVID-19; SARS-CoV-2; hypovitaminosis D; Long COVID; vitamin D
• ISSN: 0021-972X; 1945-7197; 1945-7197
• DOI: 10.1210/clinem/dgad207

Abstract Context Long COVID is an emerging syndrome affecting 50% to 70% of COVID-19 survivors that still lacks predicting factors. Objective Due to the extraskeletal effects of vitamin D, we retrospectively assessed the association between 25(OH) vitamin D levels and long COVID in COVID-19 survivors 6 months after hospitalization. Methods Long COVID was defined according to NICE guidelines. Fifty long COVID and 50 non–long-COVID subjects matched on a 1:1 basis were enrolled from an outpatient clinic post-COVID cohort seen from August to November 2020. Therapies/comorbidities affecting calcium/vitamin D/bone metabolism, and/or admission to the intensive care unit during hospitalization were exclusion criteria. 25(OH) Vitamin D was measured at hospital admission and 6 months after discharge. Results We observed lower 25(OH) vitamin D levels, evaluated at follow-up, in subjects with long COVID than those without (20.1 vs 23.2 ng/mL, P = .03). Regarding the affected health areas evaluated in the entire cohort, we observed lower 25(OH) vitamin D levels in those with neurocognitive symptoms at follow-up (n = 7) than those without (n = 93) (14.6 vs 20.6 ng/mL, P = .042). In patients presenting vitamin D deficiency (<20 ng/mL), both at admission and at follow-up (n = 42), those affected by long COVID (n = 22) presented lower 25(OH) vitamin D levels at follow-up than those not affected (n = 20) (12.7 vs 15.2 ng/mL, P = .041). In multiple regression analyses, lower 25(OH) vitamin D levels at follow-up were the only variable significantly associated with long COVID in our cohort (P = .008, OR 1.09, CI 1.01-1.16). Conclusion COVID-19 survivors with long COVID have lower 25(OH) vitamin D levels than matched patients without long COVID. Our data suggest that vitamin D levels should be evaluated in COVID-19 patients after hospital discharge. The role of vitamin D supplementation as a preventive strategy of COVID-19 sequelae should be tested in randomized controlled trials.