POAF remains a frequent complication after coronary artery bypass grafting (CABG), affecting approximately 21%–34% of patients. At the American Heart Association (AHA) 2025 Scientific Sessions, a new meta-analysis evaluated whether correcting vitamin D deficiency before surgery reduces the risk of new-onset POAF.

The analysis followed PRISMA 2020 guidelines and included randomized controlled trials (RCTs) and retrospective observational studies published between 2014 and 2024. Adult patients undergoing CABG with documented vitamin D deficiency or insufficiency were included. Outcomes were compared between patients receiving vitamin D supplementation plus standard care and those receiving standard care alone or placebo. A random-effects model was used, with heterogeneity assessed using the I² statistic.

Four randomized controlled trials comprising 694 patients were included. The mean age was 61.8 years, and 42.6% were female. Preoperative vitamin D supplementation significantly reduced the incidence of POAF in vitamin D-deficient patients, with a pooled risk ratio (RR) of 0.55 (95% confidence interval [CI], 0.40-0.76; p = 0.0003; I² = 1%). No significant effect was observed in patients with vitamin D insufficiency.

Subgroup analyses across vitamin D doses ranging from 50,000 IU to 600,000 IU showed no dose-dependent relationship. Vitamin D supplementation did not significantly affect hospital length of stay (mean difference, –0.62 days; 95% CI, –0.74 to 0.50; p = 0.28) or duration of intubation (mean difference, 0.00 hours; 95% CI, –0.26 to 0.26; p = 0.99).

These findings indicate that preoperative correction of vitamin D deficiency is associated with a significantly lower risk of POAF following CABG, while benefits were not observed in vitamin D-insufficient populations.