Maternal Hypovitaminosis D and Iron Homeostasis Biomarkers: Correlation and Regression Analysis in Iraqi Pregnant Women

Abstract

Background: Vitamin D and iron deficiencies frequently coexist during pregnancy, yet their clinical crosstalk remains debated. This study aimed to evaluate the diagnostic and predictive associations between maternal serum Vitamin D levels and key iron homeostasis biomarkers.Subjects and Methods: A cross-sectional study was conducted on 196 pregnant women (N = 196; mean age 26.8 ±6.1years). Serum Vitamin D, ferritin, total iron-binding capacity (TIBC), erythropoietin (EPO), and transferrin levels were quantified alongside socio-demographic and obstetric parameters. Data were analyzed using Spearman correlation, multiple linear regression, and receiver operating characteristic (ROC) curves.Results: Overall, 63.8% (n = 125) of participants exhibited Vitamin D inadequacy (<30ng/mL). Vitamin D3 showed no significant linear correlations with ferritin (r = 0.064), transferrin (r = 0.053), or EPO (r = 0.031), though a trend with TIBC emerged (r = -0.150, p = 0.069). Ferritin inversely correlated with EPO (r = -0.270, p = 0.010). After controlling for confounders, Vitamin D was not an independent predictor of any iron biomarker (all p > 0.05). ROC analyses confirmed poor diagnostic performance for all iron markers in predicting Vitamin D status (AUC = 0.413–0.587, all p > 0.05).Conclusion: Serum iron homeostasis biomarkers do not reliably reflect or predict maternal Vitamin D status, highlighting the need for independent screening of both micronutrients during antenatal care.