Postpartum depression (PPD) is a significant mental health case after childbirth, distinguished by behavioral changes and emotional disturbance. PPD is a significant public issue estimated to affect 10–15% of women worldwide. The study's objective was to investigate whether low sera concentrations of vitamin D, calcium, and magnesium during the third trimester of pregnancy are associated with PPD. The study population included eighty pregnant women between the ages of 25 to 35 years. They were divided into two groups (control and depressed group). Simple samples technique collecting was used for serum collecting from the two groups. When the blood samples were taken, vitamin D level was determined using an ELISA device. Calcium and magnesium were measured by using the spectrophotometric method. A health questionnaire structure was used for screening depression after birth. After measuring pregnancy serum concentrations of vitamin D of (40) pregnant control and (40) pregnant with PPD, we found that there was no significant relationship between vitamin D concentrations and risk of PPD (p= 0.6497). Statistical analysis indicated the significant differences (p= 0.0003) between sera calcium levels of the control group as compared with the depressed group. Significant differences (p= 0.0005) in magnesium levels between the two groups were observed. Our study detected that vitamin D concentrations in the serum of women during their last trimester of pregnancy had no statistical link with their risk of PPD. Whereas direct associated with calcium and magnesium deficiency in the third trimester of pregnancy and the incidence of PPD were reported.