«Prevalence of Vitamin D Deficiency and Insufficiency Across Trimesters of Pregnancy in Maiduguri, Nigeria: A Cross-Sectional Study». African Journal of Biomedical Research 24, no. 1 (enero 31, 2021): 53–57. Accedido abril 5, 2026. https://ojshostng.com/index.php/ajbr/article/view/1689.