Tabriz University of Medical Sciences Journal of Research in Clinical Medicine 2717-0616 14 1 2026 01 01 Association of serum calcium, phosphorus, and vitamin D Levels with clinical severity in patients with chronic obstructive pulmonary disease: A single-center study 34761 34761 10.34172/jrcm.026.34761 EN Shima Nabavi https://orcid.org/0000-0002-0237-5485 Mahnaz Mozdourian Muhammad Islampanah https://orcid.org/0000-0001-6892-868X Adele Azarshab https://orcid.org/0000-0002-1126-9385 Younes Ghanbari https://orcid.org/0009-0008-0071-5010 Journal Article 10.34172/jrcm.026.34761 2024 02 07 2024 11 20 Introduction: This study aimed to evaluate serum concentrations of calcium, phosphorus, and vitamin D in patients diagnosed with chronic obstructive pulmonary disease (COPD). Methods: This study was conducted at the Mashhad University of Medical Sciences, Iran, between 2021 and 2022, focused on assessing the neutrophil-to-lymphocyte ratio (NLR) in COPD patients. Data was collected from clinical files, laboratory results, and direct patient interviews, with an emphasis on demographic data, medical history, and a variety of laboratory and clinical parameters. COPD severity was assessed using clinical criteria and spirometry. Results: The study included 49 COPD patients, with a mean age of 62.3±8.70 years, 59% of whom were male. Common comorbidities included hypertension (43%) and diabetes (12%). Serum analysis indicated an average calcium level of 9.50 mg/dL and vitamin D3 level of 26 ng/ml. Most patients were prescribed SEROFLO (82%) and TIOVA (92%). Severity of COPD was categorized as 49% in mMRC Grade 2, 43% in AECOPD Category 0, and 67% in GOLD Grade 2. A significant variation in vitamin D3 levels was observed across different GOLD Spirometry Classifications (P=0.02). However, there was no significant correlation observed between calcium and phosphorus levels and COPD severity indicators. Conclusion: The study revealed a significant variation in vitamin D3 levels among different GOLD Spirometry Classifications in COPD patients, suggesting that vitamin D3 may play a role in the severity of COPD. However no significant association was found for calcium and phosphorus levels with COPD severity, their role should not be disregarded and warrants further investigation.