Association between maternal vitamin D, calcium, and inflammatory cytokines in Iraqi pregnant women with placental calcification

Placental calcification is an aging process that is increasingly linked to adverse pregnancy outcomes when it occurs prematurely. Vitamin D has immunomodulatory properties and may play a role in placental calcification. This study explored the association between maternal vitamin D, inflammatory cytokines, and placental calcification. A total of 46 pregnant women aged 16–40 years were included in this study. They were divided into four groups: Group 1 (control group; n = 10, without placental calcification), Group 2 (n = 12, Grade 1 placental calcification), Group 3 (n = 12, Grade 2 placental calcification), and Group 4 (n = 12, Grade 3 placental calcification). Serum vitamin D (25(OH)D) and cytokine (TNF-α, IL-2, IL-4, IL-10) levels were measured by ELISA, while serum calcium levels were measured by colorimetric analysis. Vitamin D levels declined gradually with increasing placental calcification ( p = 0.0146 for G3 vs. control). Calcium levels did not differ significantly across groups ( p > 0.05). The pro-inflammatory marker TNF-α was significantly increased in G3 compared to the control group ( p = 0.016). Similarly, IL-2 levels increased, but the difference was not statistically significant. In contrast, anti-inflammatory cytokines IL-4 and IL-10 decreased, with IL-10 showing a significant positive correlation with vitamin D levels ( r = 0.8403, p = 0.0006). These findings suggest that vitamin D deficiency may play a significant role in placental calcification, mediated by elevated pro-inflammatory cytokine TNF-α and reduced anti-inflammatory cytokine IL-10.