The Association between Serum Ferritin Levels and 25(OH)D Levels in Adult Patients with Transfusion Dependent Thalassemia

Deficiency and insufficiency of 25(OH)D in thalassemia patients are still high even in countries with abundant sun exposure or with vitamin D supplementation. Long term routine blood transfusions in thalassemia patients cause iron overload which is characterized by increase in serum ferritin levels. Liver damage due to iron overload is thought to disrupt synthesis of 25(OH)D in the liver. This study aimed to determine the association between serum ferritin levels and 25(OH)D levels in adult patients with transfusion dependent thalassemia. This was a cross-sectional observational analytic study. The blood sample were collected from adult patients with transfusion dependent thalassemia to measure the levels of serum ferritin using the electrochemiluminescence immunoassay (ECLIA) method and 25(OH)D levels using the chemiluminescence microparticle immunoassay (CMIA) method. There were 45 subjects, 24 males and 21 females with median age of 23 years; duration of transfusions was 16.3 ± 6.2 years. 23 subjects used deferasirox and 22 subjects used deferiprone iron chelator. The median of serum ferritin levels was 4,467 ng/mL and the mean of 25(OH)D levels was 12.69 ± 4.84 ng/mL. There was significantly negative association between serum ferritin levels and 25(OH)D levels (r = - 0.41, p = 0.003). In this study, significantly negative association was found between serum ferritin levels and 25(OH)D levels. High serum ferritin levels may decrease 25(OH)D levels in adult patients with transfusion dependent thalassemia.