Vitamin D levels in patients with small and medium vessel vasculitis Fatma Nur Korkmaz, Gulsen Ozen, Ali Ugur Unal, Asli Odabasi, Meryem Can, Ebru Asıcıoglu, Serhan Tuglular, Haner Direskeneli

Vitamin D is not useful as a biomarker for disease activity in rheumatoid arthritis Paola de la Torre Lossa, Mario Moreno Álvarez, María del Carmen González Guzmán, Rafael López Martínez, Carlos Ríos Acosta

Vitamin D Insufficiency and Deficiency in Mexican Patients With Systemic Lupus Erythematosus: Prevalence and Relationship With Disease Activity Mario García-Carrasco, Claudia Mendoza-Pinto, Ivet Etchegaray-Morales, Pamela Soto-Santillán, Erick Alejandro Jiménez-Herrera, Viridiana Robles-Sánchez, Alma Rodríguez-Gallegos, Araceli Ramos-Varela, Margarita Muñoz-Guarneros, Alejandro Ruiz-Argüelles