Vitamin D Receptor Mrna Expression And Serum Vitamin D Levels In Post Covid Vaccinated Patients

Abstract

Title: Vitamin D Receptor (VDR) mRNA Expression and Serum Vitamin D Levels in Post-COVID Vaccinated Patients newlineBackground newlineThe unprecedented scale of the COVID-19 pandemic led to rapid development and deployment of vaccines that have proven highly effective in reducing morbidity and mortality. However, growing evidence indicates that vaccine-induced immune responses are heterogeneous across populations, influenced by genetic, nutritional, and immunological factors. Vitamin D has emerged as a pivotal immunomodulatory micronutrient, exerting its biological effects primarily through the vitamin D receptor (VDR), a ligand-activated transcription factor expressed in most immune cells. The VDR vitamin D axis regulates innate and adaptive immune responses, cytokine signaling, antimicrobial peptide synthesis, and calcium homeostasis. newlineIndia, despite abundant sunlight, continues to report widespread vitamin D deficiency, which may compromise immune competence even after successful vaccination. Although several studies have explored serum vitamin D levels in COVID-19 infection and vaccination, there remains a critical knowledge gap regarding transcriptional regulation of the VDR gene following vaccination and its relationship with biochemical and endocrine markers. Importantly, the potential differential impact of booster vaccination versus partial vaccination on VDR mRNA expression and vitamin D calcium PTH homeostasis has not been systematically studied. newlineThis doctoral research therefore sought to examine whether COVID-19 Covishield booster vaccination induces measurable molecular and biochemical changes in the vitamin D VDR axis and whether these changes reflect immune-driven metabolic adaptation rather than endocrine dysfunction. The conceptual basis was that vaccination, as a strong immunological stimulus, may upregulate VDR transcription to meet increased immunoregulatory demand for vitamin D signaling. newlineObjectives newlineThe primary objective was to quantify and compare VDR mRNA expression, serum 25-hydroxyvitamin D [25(OH)D],