Introduction Vitamin D deficiency co-exists with and can confuse the diagnosis of primary hyperparathyroidism (PHPT). Vitamin D replete (VDR) status may prevent significant postparathyroidectomy hypocalcaemia; however, reports from previous studies are conflicting. This study aimed to assess differences in early and/or late postoperative hypocalcaemia and length of stay (LOS) postparathyroidectomy between VDR and vitamin D non-replete (VDNR) PHPT patients. Methods This was a retrospective cohort study of a prospectively maintained single surgeon operative database. All records of patients who underwent parathyroidectomy over a four-year period (July 2014 to December 2018) were extracted. Data were collected on vitamin D and corrected calcium levels pre- and postoperatively as well as postoperative complications and LOS. Results On presentation, there were 91 (47.9%) VDR and 99 (52.1%) VDNR patients. Following vitamin D therapy there were 148 (77.9%) VDR and 42 (22.1%) VDNR. The multivariate analysis showed that vitamin D status was the only significant factor impacting on the hypocalcaemia symptoms (OR 4.9, 95% CI 1.8–13.7, p = 0.002) and the most significant factor for the calcium supplementation (OR 6.5, 95% CI 2.1–19.4, p = 0.001). Bilateral neck exploration was associated with increased likelihood of transient hypocalcaemia (p = 0.007) but no other post-op complication. Median LOS was significantly shorter for VDR (1 day) versus VDNR (1.5 days) patients (p = 0.001). Conclusion There is a statistically significant increased likelihood of postoperative hypocalcaemia symptoms, requirement for calcium supplements and increased LOS in VDNR patients. This study suggests optimising preoperative vitamin D status improves patient experience and could reduce healthcare costs.
