DIAGNOSIS OF VITAMIN B12 DEFICIENCY IN CHILDREN BY USING METHYLMALONIC ACID, HOMOCYSTEINE AND HOLOTRANSCOBALAMINE

Authors : Serap Kirkiz, Özlem Arman Bilir, Fatih Mehmet Azik, Çiğdem Sönmez, Hüsniye Neşe Yarali

Pages : 200-206

Doi:10.24938/kutfd.1263790

View : 28 | Download : 37

Publication Date : 2023-08-31

Article Type : Research Article

Abstract :Objective: Vitamin B12 deficiency is a common health issue in children. Though the sensivity of serum vitamin B12 measurement for the diagnosis of vitamin B12 deficiency is low, combined methylmalonic acid, homocysteine and holotranscobalamin have been reported to be more specific biomarkers in early and accurate diagnosis. In this study, we aimed to verify the diagnosis of vitamin B12 deficiency in children by measuring methylmalonic acid, homocysteine, holotranscobalamin and to determine the accuracy of them. Material and Methods: The study included 277 patients aged 0.4 μmol L, holotranscobalamin <21 pmol/L. Homocysteine levels were evaluated according to age. Results: There was a positive correlation (kappa index 0.387) between vitamin B12 and holotranscobalamin and a negative correlation between vitamin B12, methylmalonic acid and homocysteine levels (kappa index -0.134, -0.258, respectively). There was a weak correlation between methylmalonic acid and holotranscobalamin; methylmalonic acid and homocysteine; homocysteine and holotranscobalamin (kappa index -0.039, 0.243, -0.377, respectively). Patients were divided into 4 groups according to holotranscobalamin, homocysteine and methylmalonic acid levels. Seventy-three patients (26%) had low holotranscobalamin. Group 1a was consisting of 37 patients who were diagnosed vitamin B12 deficiency with low serum B12 and supported by all 3 parameters. When all groups were compared, vitamin B12 and hemoglobin levels were found to be lower in Group 1a than other groups (respectively, p<0.05, p<0.001) Conclusion: In children, holotranscobalamin alone should not be considered an accurate indicator, and other functional markers should be combined in the diagnosis of vitamin B12 deficiency. Furthermore, most studies about vitamin B12 deficiency were carried out in adult age groups, and studies are needed in children to determine the reference intervals for holotranscobalamin and serum methylmalonic acid.
Keywords : Vitamin B12, metilmalonik asit, holotranskobalamin