Alfrehat, E. N., Alnsour, E. M., Al Hmeisat, E. M. and Alsoleihat, F. (2025) “Prevalence and Correlation of Vitamin B12 and Vitamin D Levels Among Jordanian Patients”, European Scientific Journal, ESJ, 21(6), p. 109. doi: 10.19044/esj.2025.v21n6p109.