Prevalence and predictors of vitamin D deficiency in Lebanon: 2016-2022, before and during the COVID-19 outbreak.

Background: Vitamin D deficiency is very common worldwide, particularly in Middle-Eastern countries. Recent Lebanese studies demonstrated an improvement in vitamin D status over time. However, the comparison between the years before and during the COVID-19 outbreak has never been analyzed in the Middle-East area. This study aimed to determine the prevalence and the predictors of 25-hydroxyvitamin D (25(OH)D) levels during the last 7 years.

Methods: Serum 25(OH)D levels from a large laboratory database were retrospectively collected from Hôtel-Dieu de France Hospital between January 2016 and June 2022 (N = 66,127). Data related to age, gender, season and year of sampling were also retrieved.

Results: Mean age of the population was 50.6 ± 19 years, 62.7% were women, 5.3% were children and adolescents, 67.6% adults and 27% elderly. Mean serum 25(OH)D level was 25.7 ± 11.9 ng/mL. The overall population with vitamin D sufficiency (>30 ng/mL) was 31.9%. The increase in mean serum 25(OH)D observed between 2016 and 2022 was 6.36 ng/mL (p < 0.0001). The prevalence of 25(OH)D deficiency (<30 ng/mL) decreased from 76.2% in 2016 to 56.5% in 2022 (p < 0.0001) with a significant difference between the period before and during the COVID-19 outbreak (72.3% vs.42.5%, p < 0.0001). In a multivariate logistic regression, older age, female sex, summer season, years of the COVID-19 outbreak and outpatient samples were protective factors against the risk of hypovitaminosis D (p < 0.0001 for all variables).

Conclusion: Our study showed a continuous positive change in vitamin D status time, most notably after the COVID-19 outbreak. Further studies are needed to assess the clinical impact of the pandemic on vitamin D status in our population.