Ezzoubi Nada, Azzaoui Siham, Echcharii Nadia and Dini Nouzha 2025. Vitamin B12 Deficiency Revealed by Severe Pancytopenia: A Case Study. International Journal of Scientific Research and Innovative Studies. 4, 5 (Oct. 2025), 53–56. DOI:https://doi.org/10.63883/ijsrisjournal.v4i5.479.