Vitamin D maintenance in postoperative patients (D-ECISIVE): a study protocol for a randomized controlled trial.

Abstract

Background: Vitamin D plays a critical role in maintaining calcium and phosphate homeostasis, muscle health, and postoperative recovery. Patients undergoing surgery face an increased risk of vitamin D insufficiency because of reduced sun exposure, altered nutritional intake, and preexisting deficiencies, factors that may compromise muscle function and impair recovery and quality of life. However, there is currently no standardized protocol for postoperative vitamin D maintenance. Therefore, this study aims to evaluate whether monthly high-dose vitamin D supplementation (50,000 IU) maintains serum vitamin D levels and improves postoperative muscle function and quality of life compared with standard care.

Study design: This single-center, open-label, randomized controlled trial will recruit adults aged 21 to 65 years who have undergone major surgery and have serum 25-hydroxyvitamin D levels between 30 and 50 ng/mL at 4 to 6 weeks postoperatively. Participants will be randomly assigned in a 1:1 ratio to receive either monthly high-dose vitamin D supplementation (50,000 IU cholecalciferol) for 6 months or standard postoperative care without routine vitamin D supplementation. Outcome assessors will be blinded to group allocation. The primary outcome is maintenance of serum 25-hydroxyvitamin D levels at 3 months after the intervention. Secondary outcomes include serum vitamin D levels at 6 months; assessments of muscle function, including handgrip strength, 6-minute walk test, and 5 times chair stand test; evaluations of muscle quality using the intramuscular adipose tissue index; and quality of life measured by the EuroQoL 5-dimension 3-level (EQ-5D-3L) instrument.

Outcome: This study will provide evidence on whether monthly high-dose vitamin D supplementation supports muscle recovery and quality of life in postoperative patients. The findings may help establish standardized guidelines for postoperative vitamin D maintenance and inform future supplementation strategies in surgical populations.

Trial registration: ClinicalTrials.gov identifier: NCT06708741. Registered on November 26, 2024.