Why this study is important
Despite growing interest in the extra-skeletal effects of vitamin D, particularly its immunomodulatory and anti-inflammatory properties, its relationship with routinely available platelet and inflammatory markers remains poorly defined. Existing studies have mostly focused on patients with chronic diseases such as diabetes, cardiovascular disease, or autoimmune disorders, leaving a gap in our understanding of whether vitamin D influences these parameters in young, apparently healthy individuals. This study addresses that gap by systematically evaluating the association between vitamin D levels and key platelet indices (MPV, PDW, PLR, NLR) in a well-defined cohort of young adults without comorbidities or regular medication use. By focusing on a population free from significant inflammatory or metabolic confounders, the findings help establish a baseline reference and highlight that the previously reported associations in patient populations may be context-dependent rather than universal. Clarifying this distinction is important for avoiding overinterpretation of routine hematological parameters in low-risk individuals and for guiding future research toward populations where vitamin D truly exerts measurable effects on platelet biology.
Abstract
Background: Recently, there has been growing interest in the roles of vitamin D and certain platelet characteristics, such as mean platelet volume (MPV). However, the influence of vitamin D levels on these platelet traits is still under discussion. The available research on the relationship between vitamin D levels and platelet parameters, including MPV, Platelet Distribution Width (PDW), Platelet Lymphocyte Ratio (PLR), and Neutrophil Lymphocyte Ratio (NLR), is currently limited. The objective of our study was to examine the association between vitamin D levels and platelet parameters in apparently healthy individuals.
Methods: In this study, we evaluated vitamin D levels alongside complete blood count parameters in patients presenting to family medicine polyclinics with non-specific complaints such as fatigue and generalized weakness. Eligible participants were aged 18-28 years and had no history of chronic disease, regular medication use, or pregnancy. From an initial cohort, 877 participants met the inclusion criteria. Individuals with vitamin D levels exceeding 150 ng/mL were excluded. The remaining participants were stratified into three groups according to their serum vitamin D concentrations: 30-150 ng/mL, 20-30 ng/mL, and <20 ng/mL.
Results: When the vitamin D groups were evaluated in terms of MPV, PDW, PLR, and NLR, no significant difference was found (p = 0.112, p = 0.236, p = 0.223, and p = 0.249, respectively). Additionally, when using the Spearman correlation test, we did not observe any significant correlation between vitamin D and the other inflammatory biomarkers examined in our study (p>0.05). Furthermore, after gender adjustment, we found that the correlation between vitamin D and other biomarkers investigated in our study was not significant (p>0.05).
Discussion: The absence of significant association observed in this young, ostensibly healthy cohort suggests that the potential immunomodulatory and anti-inflammatory effects of vitamin D may not translate into measurable changes in standard platelet parameters in the absence of significant inflammatory or metabolic pathology. This observation aligns with the concept that vitamin D’s impact on hematological indices might be context- dependent, becoming more pronounced in states of chronic disease, heightened inflammation, or advanced age.
Conclusion: It can be concluded stating that, no significant effect of vitamin D levels on MPV, PDW, PLR, and NLR parameters was observed. However, the sample size for this research was limited. To better understand the relationship between vitamin D levels and platelet parameters, larger and prospective cohort studies are required.
Keywords: Vitamin D; hematology; lymphocyte ratio; mean platelet volume; neutrophil lymphocyte ratio.; platelet; platelet distribution width.
Authors:
Samet Uludag and Kadir Uludag.
link of study: https://pubmed.ncbi.nlm.nih.gov/41764613/
