Maghbooli Z, Ebrahimi Meimand S, Malek Hosseini A, Shirvani A. Alterations in circulating levels of vitamin D binding protein, total and bioavailability of vitamin D in diabetic retinopathy patients. BMC Endocrine Disorders. 2022 Jul 01;22(1):169. doi: 10.1186/s12902-022-01084-6.