Serum manganese level in children with iron deficiency

Introduction
Iron deficiency (ID) is the most common nutritional deficiency all over the world, especially in developing countries, and it is an important public health issue in childhood. ID may be associated with excess trace element absorption such as manganese (Mn) from the gastrointestinal tract. The present study investigated serum Mn concentrations in children with ID.

Material and methods
This interventional study included 63 children aged 5–12 years, with ID, using WHO criteria, compared with 30 age- and sex-matched controls. The children were recruited from paediatric clinics, Medical Research Excellence Centre (MREC) at the National Research Centre from August 2017 to December 2018. Serum Mn levels were measured by inductively coupled plasma mass spectrometer plus haematological and iron indices.

Results
Serum Mn concentration was significantly increased in children with ID compared with controls (p < 0.001), while there was significant reduction in haematological and iron indices in the ID group. The serum transferrin receptor and transferrin were higher in the ID group compared to controls, but not significantly. Multiple regression analysis showed negative correlation between serum Mn and serum iron, serum ferritin, and transferrin saturation percentage (r = –0.33, p = 0.01; r = –0.32, p = 0.01; r = –0.3, p = 0.02), respectively. Improvement in haematological and iron indices and Mn occurred after iron supplementation for eight weeks in the ID group.

Conclusions
High serum Mn concentration was reported in ID children of this age group that decreased significantly after oral iron therapy; hence, the Mn level must be assessed simultaneously with haematological and iron indices in case of ID state. Early diagnosis and treatment of ID in children is recommended both to avoid complications of ID and to decrease Mn toxicity risk, which may lead to neurodevelopmental and intellectual impairment.