Serum 25(OH)D is associated with an altered bone turnover marker response after a hip fracture

ABSTRACT C‐terminal telopeptide of type I collagen (CTX) and procollagen type 1 N‐terminal propeptide (P1NP) are bone turnover markers (BTMs) that are promising surrogate measures of fracture healing; however, it is unknown if their response is affected by other bone healing metabolites. Since 70% of fracture patients are reported to have insufficient serum vitamin D, we sought to determine if serum 25(OH)D levels are associated with differential changes in CTX and P1NP concentrations after hip fracture. This prospective cohort included hip fracture patients 65 years of age or older admitted to one of eight Baltimore‐area hospitals. Serum samples were collected at baseline, 2‐, 6‐, and 12‐month post‐fracture. A mixed‐effects repeated‐measures analysis was used to determine the longitudinal association between vitamin D deficiency (25(OH)D