Vitamin D status and Its association with haematological inflammatory indices and cardiometabolic risk profiles: a retrospective cross-sectional study

Cardiovascular disease remains the leading cause of global mortality, with dyslipidaemia and impaired glycaemic control representing central modifiable risk factors. Haematological inflammatory indices and vitamin D status have each been independently associated with cardiovascular risk; however, their potential interaction remains underexplored. This study evaluated whether vitamin D status exhibited differential relationships with cardiometabolic risk markers.

This retrospective cross-sectional study included 1,100 adults attending King Faisal University polyclinics between January and March 2026. Participants were categorised as vitamin D sufficient (≥30 ng/mL, n = 175), vitamin D insufficient (20-29 ng/mL, n = 470), and vitamin D deficient (<20 ng/mL, n = 455). Haematological inflammatory indices, including the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), monocyte-to-lymphocyte ratio (MLR), and systemic immune-inflammation index (SII), were calculated. Associations with lipid and glycemic parameters were evaluated using correlation analyses, logistic regression, and receiver operating characteristic curve analysis.

Vitamin D deficiency was associated with adverse inflammatory and cardiometabolic profiles, indicating that low vitamin D status coexisted with less favorable inflammatory and metabolic profiles. Although the NLR, PLR, and SII were consistent markers, their modest discriminatory performance limits standalone diagnostic use. These findings suggest that vitamin D status may be associated with differential relationships between haematological inflammatory indices and cardiometabolic risk markers.