Photo Credit: Freepik

The following is a summary of “Vitamin D Status and Incidence of SARS-CoV-2 Reinfections in the Borriana COVID-19 Cohort: A Population-Based Prospective Cohort Study,” published in the April 2025 issue of Tropical Medicine and Infectious Disease by Domènech-Montoliu et al. 

The association between deficient vitamin D (VitD) status and SARS-CoV-2 infections, severity, and mortality had been established, but its relationship with SARS-CoV-2 reinfections had received limited study.  

Researchers conducted a retrospective study to quantify the risk of SARS-CoV-2 reinfections based on VitD status prior to reinfection.  

They performed a study in Borriana (Valencia Community, Spain) from 2020 to 2023, measuring 25-hydroxyvitamin D [25(OH)D] levels using electrochemiluminescence and Cox proportional hazards models were employed for analysis.  

The results showed that out of 644 confirmed SARS-CoV-2 cases, 378 (58.9%) were included in the study, with an average age of 38.8 years. Among the participants, 241 were females (63.8%), and 127 reinfections occurred (33.6%). The incidence rates of SARS-CoV-2 reinfections per 1,000 person-days were 0.50 for deficient VitD status (<20 ng/mL), 0.50 for insufficient status (20–29 ng/mL), and 0.37 for sufficient status (≥30 ng/mL). When compared with sufficient VitD status, adjusted hazard ratios were 1.79 (95% CI, 0.89–3.59) for deficient status and 1.59 (95% CI, 1.06–2.38) for insufficient status, showing a substantial inverse dose–response (P = 0.02).  

Investigators concluded that a VitD status below 30 ng/mL was associated with a higher risk of SARS-CoV-2 reinfection, supporting the recommendation of achieving and maintaining sufficient VitD levels for reinfection prevention. 

Source: mdpi.com/2414-6366/10/4/98