Context
Whether pre-operative vitamin D deficiency (VDD) contributes to post-operative hypoparathyroidism (hypoPT) risk is unknown.
Objective
To meta-analyze the best available evidence regarding the association between pre-operative vitamin D status and hypoPT risk.
Data Sources
A comprehensive literature search was conducted in PubMed, CENTRAL and Scopus databases, up to October 31, 2020.
Study Selection
Patients undergoing thyroidectomy with pre-operative vitamin D status and post-operative hypoPT data.
Data Extraction
Two researchers independently extracted data from eligible studies.
Data synthesis
Data were expressed as risk ratio (RR) with 95% confidence interval (CI). The I 2 index was employed for heterogeneity.
Results
Thirty-nine studies were included in the quantitative analysis (61,915 cases with transient and 5,712 with permanent hypoPT). Patients with VDD demonstrated a higher risk for transient hypoPT compared with those with pre-operative vitamin D sufficiency (RR 1.92, 95% CI 1.50-2.45, I 2 85%). These results remained significant for patients with pre-operative 25(OH)D concentrations ≤20 ng/ml (mild VDD; RR 1.46, 95% CI 1.10-1.94, I 2 88%) and ≤10 ng/ml (severe VDD; RR 1.98, 95% CI 1.42-2.76, I 2 85%). The risk of permanent hypoPT was increased only in cases with severe VDD (RR 2.45, 95% CI 1.30-4.63, I 2 45%). No difference was evident in subgroup analysis according to study design or quality.
Conclusions
Patients with pre-operative VDD are at increased risk of transient hypoPT following thyroidectomy. The risk for permanent hypoPT is increased only for those with severe VDD.
