Features of diagnosis and treatment of patients with vitamin D deficiency in real clinical practice

AIM: The purpose of this study was to analyze the characteristics of management, diagnosis and treatment of patients with vitamin D deficiency/ by endocrinologists in the regions of Russian Federation using a sociological survey. MATERIALS AND METHODS: A cross-sectional sociological uncontrolled study was carried out. To implement this work, we used an online questionnaire “Questioning doctors on vitamin D” specially developed on the basis of the Google forms platform. The study was conducted in January 2021. All the data obtained were entered into an electronic database in MS Excel. Statistical processing was performed using the IBM SPSS Statistics 25 software. RESULTS: The survey involved 707 physicians from 86 regions of the Russian Federation. Our study revealed that not all doctors strictly adhere to clinical recommendations in patient management. Issues identified include unjustifiably widespread ordering of 25(OH)D blood tests (58.5%), lack of consideration for individual patient characteristics and clinical situations in dose selection (99.2%) and prescription of active metabolite or analogs of vitamin D to correct low 25(OH)D levels in blood (14.7%). Furthermore, recommendations for improving clinical guidelines focused on the lack of illustrative material (21.1%), expanding patient information sections (20.7%), and insufficient coverage of issues arising in clinical practice (14.6%). Our study also highlighted limited capabilities of laboratory diagnostics for assessing vitamin D status in patients in Russia. The survey revealed that only 9.2% of respondents have the ability to measure 1,25(OH)2D concentrations, and only 1.4% can order tests for 24,25(OH)2D. About 8.3% of participants did not specify which tests for assessing vitamin D status are available for prescription. Technical enhancement of laboratories and the inclusion of all recommended laboratory study requirements in the compulsory health insurance system could address this. Regarding vitamin D toxicity, 25% of surveyed doctors encountered it. Main causes included self-administration of elevated doses of cholecalciferol by patients (62%) or prescribed by physicians (40%), the use of active metabolites or analogs of vitamin D (21%), incorrect dosing of cholecalciferol preparations as indicated by the manufacturer (18%), and defects in CYP24A1 (13%). Rare causes included granulomatous and lymphoproliferative diseases (11.5%). CONCLUSION: The current clinical guidelines of the Russian Association of Endocrinologists for «Vitamin D Deficiency in Adults» are generally effective and widely used by clinicians. However, they do not entirely meet the needs of specialists and require refinement in terms of improving structure and clarity of presentation, expanding illustrative material, and justifying the frequency of laboratory diagnostics. Cases of vitamin D toxicity observed in clinical practice were predominantly associated with incorrect administration of vitamin D supplements. The identified high frequency of vitamin D toxicity in real clinical practice necessitates additional attention to this issue during the update of clinical recommendations.