VITAMIN D VALUE IN DIAGNOSIS AND TREATMENT OF HYPERPARATHYROIDISM

Background: Pathophysiologic interaction between vitamin D and hyperparathyroidism (HPT) is under investigation, never being systematically studied and remaining incompletely understood till now. Aim: To define the effect of vitamin D insufficiency/deficiency on the clinical course of HPT as well as on the pre- and postoperative periods in patients with primary HPT. Materials and methods: Definition of vitamin D level, a test with alfacalcidol, and a fine-needle aspiration punction biopsy together with determination of parathyroid hormone (PTH) level in the needle lavage were included into the laboratory and instrumental examination of 374 patients with increased PTH level. Results: Definition of the vitamin D level gives a chance to differentiate between a mild form of primary HPT and secondary HPT in patients with vitamin D insufficiency/deficiency. Information on the vitamin D insufficiency/deficiency in primary HPT patients at the pre-surgical stage allows to forecast significant decrease in the ionized calcium level in the postoperative period. Conclusion: Definition of vitamin D level is a necessary component of laboratory diagnostics in all patients with a raised PTH level. Every patient with normocalcemia, normocalciuria and increased PTH level should undergo verification of HPT using the test with alfacalcidol. Normocalcemic variant of primary HPT is due to the vitamin D insufficiency/deficiency. The vitamin D insufficiency/deficiency, defined in patients at the pre-surgical stage, gives an opportunity to suggest a significant decrease in the serum ionized calcium level after parathyroidectomy and to start in time an oral treatment of hypocalcemia, providing differentiation between primary HPT recurrence and vitamin D insufficiency/deficiency in postoperative period, thereby avoiding additional observation and unjustified repeated operations.