The Relationship Between Serum Vitamin C Levels and Spontaneous Ecchymosis: A Retrospective Study

Introduction: Spontaneous ecchymosis, defined as bruising occurring without identifiable trauma, presents a diagnostic challenge and may reflect underlying vascular, hematologic, or connective tissue abnormalities. Vitamin C plays a critical role in collagen synthesis and vascular integrity, and severe deficiency is known to cause capillary fragility and bleeding manifestations. However, the relationship between serum vitamin C levels and spontaneous ecchymosis in patients without overt deficiency remains unclear. This study aimed to investigate the association between serum vitamin C levels and spontaneous ecchymosis in patients without known coagulopathies, vascular diseases, or traumaMethods: In this retrospective study, 252 individuals evaluated in a hematology clinic were included, comprising 145 patients with spontaneous ecchymosis and 107 controls. Demographic data, hematologic parameters, coagulation factors, and biochemical markers were analyzed. Group comparisons were performed using the Mann–Whitney U test or chi-square test as appropriate. To control for multiple comparisons, p-values were adjusted using the Benjamini–Hochberg false discovery rate (FDR) method. Multivariable logistic regression analyses were conducted to identify independent predictors of spontaneous ecchymosis.Results: Serum vitamin C levels did not differ significantly between the spontaneous ecchymosis and control groups (median 0.6 mg/dL in both groups; p=0.817). After FDR correction, PT, fibrinogen, von Willebrand factor antigen and activity, Factor VIII, Factor XI, vitamin B12, white blood cell count, platelet count, and mean corpuscular volume (MCV) remained significantly different between groups. In the clinically adjusted regression model, vitamin C was independently associated with spontaneous ecchymosis (OR=0.563, 95% CI 0.382–0.831; p=0.004). However, this association was attenuated after inclusion of laboratory variables in the fully adjusted model. In the final model, only MCV remained independently associated with spontaneous ecchymosis (OR=1.117, 95% CI 1.037–1.202; p=0.003), although the effect size was modest and values were within the normal range.Conclusion: Serum vitamin C levels were not associated with spontaneous ecchymosis in this cohort without profound vitamin C deficiency. The findings suggest that subclinical variations in vitamin C are unlikely to be a primary driver of spontaneous ecchymosis. The condition appears to be multifactorial, with vascular and connective tissue mechanisms potentially playing a larger role.