Association of Circulating Vitamin D With Colorectal Cancer Depends on Vitamin D–Binding Protein Isoforms: A Pooled, Nested, Case-Control Study

Higher circulating 25-hydroxyvitamin-D [25(OH)D] concentrations are consistently inversely associated with colorectal cancer (CRC) risk in observational studies. However, it is unknown whether this association depends on the functional GC-rs4588*A (Thr436Lys) variant encoding the vitamin D-binding protein-2 (DBP2) isoform, which may affect vitamin D status and bioavailability.We analyzed data from 1710 incident CRC cases and 1649...