Objectives: To evaluate serum levels of vitamin D (VD), hepcidin, interleukin (IL)-6 and iron indices in pregnant women Patients & Methods: 88 pregnant women fulfilling the inclusion criteria underwent full clinical examination and gave blood samples for determination of hemoglobin concentration (Hb. Conc.), and ELISA estimation of serum 25-hydroxy VD (25OH-VD), ferritin concentration (SFC), hepcidin and IL-6 at the 6th wk gestational age (Booking time) and underwent re-determination of Hb. Conc. at start of the 3rd trimester and Hb. Deficit was calculated. Study outcome included determination of the frequency of iron deficiency (ID), iron deficiency anemia (IDA) and VD deficiency (VDD) and evaluation of the relations between these parameters. Results: At booking time, 17 women were anemic (Hb. Conc. <11 gm/dl), while 14 women had SFC<15 ng/ml, for a frequency of anemia, ID and IDA of 19.3%, 15.9% and 11.4%, respectively. At the 3rd trimester, 35 women had Hb. Conc. <11 gm/dl, thus the frequency of IDA was doubled during pregnancy with significantly (p=0.0029) higher frequency of anemic women and significantly (p=0.0007) lower mean Hb. Conc. compared to booking time with a median decrease of Hb. deficit by 4.96% (95% ICR: -7 to -3.23). At booking time, 17 women had insufficient VD levels and 64 women had VDD. At booking Hb. Conc. and deficit was significantly correlated with serum FC, 25OH-VD, hepcidin and IL-6. Serum 25OH-VD level showed significant correlation with SFC, hepcidin and IL-6 levels, and serum hepcidin levels was significantly correlated with serum FC and IL-6. Regression analysis defined at booking high serum hepcidin and IL-6 as significant negative, while high serum 25OH-VD level as significant positive predictor for oncoming 3rd trimester Hb. conc. For prediction of the extent of Hb. deficit, at booking high serum 25OH-VD was negative (β=-0.307, p=0.004), while serum IL-6 level was positive (β=0.235, p=0.026) significant predictors for high deficit. Conclusion: Gestational IDA is a progressive condition weakly responding to iron supplemental therapy. IDA is a multi-factorial condition strongly associated with VDD, disturbed immune milieu and deregulated iron homeostasis. VDD plays a crucial role in pathogenesis of ADI.