The role of vitamin D deficiency in parathyroid hormone levels

Abstract

Aim: Vitamin D deficiency is an important cause of secondary hyperparathyroidism. We aimed to investigate the effect of vitamin D levels on parathyroid hormone (PTH) levels. Materials and methods: We retrospectively chose 2226 patients who were admitted to our hospital's general internal medicine department for various reasons and had both PTH and vitamin D tests on the same day. Results: It was found that 22.3% of the patients had high levels of PTH and 92% of them had secondary hyperparathyroidism. The average vitamin D level was 16.4 ng/mL. The vitamin D levels of 64% of the patients were below 20 ng/mL (n = 1417), and those of the rest of the patients were above 20 ng/mL (n = 809). Of the patients with vitamin D deficiency (≤20 ng/mL), 74.7% had normal levels of PTH. Furthermore, 27.2% of patients with high levels of PTH (n = 135) received further evaluation using imaging modalities (parathyroid ultrasonography and scintigraphy), and 66.6% had normal findings (n = 90). Conclusion: Although PTH levels rise in the case of vitamin D deficiency, most of the patients had normal levels of PTH, and there were no pathological findings in the imaging studies of most of the patients with high PTH levels. © Tübi̇tak.