Researchers have found in a new study that Preoperative vitamin D supplementation appears to be safe and may help reduce hypocalcemia-related complications following parathyroidectomy. However, the current evidence supporting this benefit is low in quality, highlighting the need for better-designed studies to confirm its effectiveness.Parathyroidectomy is the treatment for primary hyperparathyroidism, yet postoperative hypocalcemia and hungry bone syndrome remain common. Vitamin D deficiency has been suggested as a modifiable risk factor, but evidence supporting preoperative supplementation is inconsistent. Primary hyperparathyroidism is an endocrine disorder characterized by excessive, unsuppressed parathyroid hormone (PTH) secretion concurrent with mild–moderate hypercalcemia. In North America, the prevalence ranges from 0.4% to 3.1%, with data variability partly due to differences in serum calcium testing availability across different geographic regions. This condition predominantly affects individuals over 40 years old and is most common in postmenopausal women. Untreated and prolonged elevation of PTH disrupts calcium homeostasis, which can cause bone mass density loss, pathologic fractures, and nephrolithiasis. When clinically indicated, surgical excision of the affected parathyroid glands is effective and used as standard treatmentFollowing PRISMA guidelines, we systematically searched five databases (up to January 2025) for studies evaluating vitamin D supplementation before parathyroidectomy in primary hyperparathyroidism. Data were extracted in duplicate, risk of bias assessed, and random-effects meta-analyses performed. Results: Nine studies (three RCTs and six cohorts; n = 2750) were included. Vitamin D supplementation significantly reduced postoperative hypocalcemia (RR: 0.35, 95% CI: 0.18–0.66), symptomatic hypocalcemia (RR: 0.53, 95% CI: 0.29–1.00), and length of stay (MD: −0.51 days, 95% CI: −0.55 to −0.46). Trends favored supplementation for decreasing the risk of hungry bone syndrome and requiring calcium supplementation. Thus preoperative vitamin D appears safe and may reduce hypocalcemia-related complications after parathyroidectomy, though current evidence is of low quality.Reference:M. Gynn, H. M. Dana, and O. Butskiy, “ Vitamin D Pretreatment to Prevent the Risk of Postoperative Hypocalcemic Complications After Parathyroidectomy in Primary Hyperparathyroidism: A Systematic Review and Meta-Analysis,” Head & Neck (2026): 1–11, https://doi.org/10.1002/hed.70205.Keywords:Preoperative, Vitamin D, Reduce, Hypocalcemia , After, Parathyroidectomy, M. Gynn, H. M. Dana, and O. Butskiy