Preoperative vitamin D replacement therapy in primary hyperparathyroidism: Safe and beneficial?

Background: The significance of vitamin D deficiency with primary hyperparathyroidism (PHPT) remains unclear. The safety and value of preoperative vitamin D (Vit D) replacement is unknown. Methods: A prospective surgical database of PHPT patients was queried to identify those who were vitamin D sufficient, deficient, and deficient but repleted. Biochemical parameters were measured preoperatively, after vitamin D replacement, at 1-month follow-up, and at 6-months follow-up. Results: Of 301 patients, 118 (39%) had a vitamin D level of 30 ng/mL or more; 71 patients (24%) were deficient, and 112 patients (37%) were vitamin D deficient but underwent repletion. The median duration of replacement was 28 days, and the dose of ergocalciferol was 400,000 U. Among the 112 patients who underwent repletion, the mean serum calcium remained relatively unchanged or decreased in 91 patients (81%). The gland size was smallest in patients with a preoperative sufficiency and largest in those deficient and not repleted. Postoperative PTH values at 1 month and at 6 months in the baseline-normal group were significantly less than in the other 2 groups (P = .05 and = .009, respectively), with no differences observed between the deficient and the deficient-repleted groups. Conclusion: Preoperative Vit D replacement therapy was safe in PHPT patients and did not increase serum calcium levels. Vit D status affects gland size and postoperative PTH elevation. Repletion in this population is not durable.