Impact of vitamin D deficiency on iron status in children with type I diabetes.

Vitamin D deficiency (VDD) and anemia are both public health nutrition concerns. An association between VDD and anemia has been suggested in various healthy and diseased populations. The current study aimed to elucidate the effect of VDD on iron status in children with type I diabetes mellitus (T1DM). The study recruited two groups of children with T1DM: control group comprised of 38 T1DM children with sufficient vitamin D (> 30 ng/ml) and a case group, consisted of 52 T1DM children with VDD (< 20 ng/ml). Both groups had comparable gender, age, BMI, and disease duration. The laboratory measurements included analysis of blood indices, markers of iron metabolism, hepcidin and inflammatory markers included interleukin 6 (IL-6) and C-reactive protein (CRP). Compared to control group, T1DM children with VDD differs specifically in terms of some markers of blood indices, such as decreased hemoglobin and increased red blood cell distribution width. Moreover, decreased serum iron, ferritin, total iron-binding capacity and transferrin along with elevated inflammatory markers were observed in case group. Results of the study indicated that VDD had increased the risk of iron deficiency anemia in children with T1DM as well as inflammatory related anemia. Furthermore, in T1DM children, VDD had raised the incidence of both absolute and functional iron deficiency, with greater incidence of the former. This study may indicate that VDD may be a risk factor that may worsen iron deficiency anemia in T1DM.