Journal of medical biochemistry, cilt.36, sa.1, ss.73-83, 2017 (SCI-Expanded)
Background: 25 (OH) vitamin D3 (25(OH) D) and parathyroid hormone (PTH) are important regulators of calcium homeostasis. The aim of this study was to retrospectively determine the cut-off for sufficient 25(OH) D in a four-season region and the influence of age, seasons, and gender on serum 25(OH) D and PTH levels.