Relationship Between the Levels of Holotranscobalamin and Vitamin B12 in Children.

The purpose of this study was to evaluate the relationship between the plasma holoTC and serum vitamin B12 in children and to identify a cutoff cobalamin values according to holoTC. One hundred and fifty-five children were enrolled into the study. All children were evaluated for hemoglobin, vitamin B12, folate, ferritin and holoTC levels. Children were grouped as with low vitamin B12 level (≤200 pg/mL, group I) and normal vitamin B12 (>200 pg/mL, group II). Serum vitamin B12, and holoTC levels were performed in each patient in the study. In 101 patients with low vitamin B12 (group I) the mean holoTC was 21.74 ± 1.14 pmol/L. In 54 children with normal vitamin B12 (group II) mean holoTC was 44.0 ± 2.7 pmol/L (p < 0.01). A ROC curve analysis was performed to delineate the optimum cut-off point for vitamin B12 level and it was found to be 165 pg/mL with a sensitivity of 70% and specificity of 74%; the area under curve was 0.783 (p < 0.01). Our study displayed a positive correlation between vitamin B12 and holoTC, and defined an optimum cutoff value for vitamin B12 as 165 pg/mL. Further studies using the markers both MMA, tHcy and holoTC to confirm the findings are needed.