E. Eyong, M. Eyong, E. Omoronyia, and L. . Ekpe, “Serum Vitamin D and Calcium Status in Pregnant Women in Calabar, Southern Nigeria”, The Nig Health J, vol. 26, no. 1, pp. 339–347, Apr. 2026, doi: 10.71637/tnhj.v26i1.1310.