Background: World Health Organization (WHO) recommended supplementation of 1500-2000 mg/day calcium to be integrated into antenatal care (ANC) programmes to prevent pre-eclampsia, but the current program has not followed these recommendation. There was limited information about factors related to calcium supplements compliance and calcium adequacy in pregnant women in Indonesia. Objective: The study aims to analyze factors related to calcium supplements compliance and calcium adequacy in pregnant women. Method: This research was observational with cross sectional design. Subjects were 96 pregnant women received calcium supplements and attended ANC in Sumbersari and Ambulu Community Health Centre, Jember Regency. Data was analyzed using logistic regression to assess factors related to calcium intake compliance. Result: Factors associated to calcium supplements compliance were family support (OR= 3.40; 95% CI: 1.29–9.01) and perceived calcium benefits (OR= 3.02; 95% CI: 1.22-7.48). A high number of subjects (76.1%) was below estimated average requirement (EAR) of calcium. The average contribution of calcium intake from supplements was only 2.6% of subject's EAR. Conclusion: This study implies that family support can improve compliance among the pregnant women and the needs of optimizing calcium supplementation program in Indonesia.