Increased vitamin B12 levels in children with zinc deficiency.
Additional nutritional deficiencies may accompany zinc deficiency. We determined the vitamin B12 levels in patients with zinc (Zn) deficiency. This retrospective study enrolled 256 patients age 6 months to 16 years (176 females and 80 males) in whom Zn levels in hair samples were measured concurrently with serum vitamin B12 and ferritin levels. For all patients, we retrospectively assessed the hair Zn levels, serum ferritin and vitamin B12 levels, red blood cell count, hemoglobin, hematocrit, mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, and red cell distribution levels. Data were analyzed to determine whether there was a significant difference between any of these parameters and the presence of vitamin B12 deficiency between patients with and without Zn deficiency. In all 118 patients had Zn levels < 100 μg/g and 138 patients had levels > 100 μg/g. No significant differences were observed in ferritin levels, red blood cell parameters, or presence of iron deficiency or anemia between the two groups (p > 0.05). The median vitamin B12 level was 323 (range 238-440) pg/mL in the Zn-deficient group and 276 (range 208-382) pg/mL in those with normal Zn levels. Vitamin B12 levels were significantly higher in the Zn-deficient group (p = 0.02). A significant negative correlation was detected between vitamin B12 levels and Zn levels (r = -0.17, p = 0.004). Vitamin B12 levels are higher in patients with Zn deficiency; thus, Zn may have a negative effect on vitamin B12 levels.