Serum 25(OH) Vitamin D Levels in Pregnant Women with Coronavirus Disease 2019 (COVID-19): A Case-Control Study - Nazaret Ferrer-Sánchez; Marina Díaz-Goicoechea; Victoria Mayoral-Cesar; Silvia Garcia-Solbas; Bruno José Nievas Soriano; Tesifón Parrón-Carreño; Ana Maria Fernandez Alonso (International Journal of Environmental Research and Public Health, 2022)