Vitamin D and Parathyroid Hormone Levels and Their Relation to Serum Ferritin Levels in Children with Thalassemia Major: One-Center Study in Western Indonesia

Background: Children with thalassemia major need regular blood transfusions to survive. These multiple transfusions put them at risk for iron overload, which result in organ damage such as parathyroid gland. The aim of this study is to determine levels of calcium, phosphorus, vitamin D and parathyroid hormone in children with thalassemia major and compare them with controls, and analyze their correlation with serum ferritin level.

Methodology: This was a cross-sectional study in 37 patients with thalassemia major in Department of Pediatrics, Dr. M. Jamil Hospital Padang and 37 age- and sex-matched healthy controls. Serum calcium ion, inorganic phosphorus, vitamin D (25-hydroxycholecalciferol), parathyroid hormone (PTH) and ferritin levels were measured.

Results: There were 18 boys and 19 girls in each group. Their age ranged between 2 and 16 years, with 20 (54%) children aged more than 10 years. Median of ferritin level in patients and controls were 2981 (IQR 3662) ng/mL and 36.6 (IQR 27.5) ng/mL respectively. Mean level of calcium ion and phosphorus levels in patients were 1.17 (SD 0.07) mmol/L and 5.42 (SD 0.76) mg/dL respectively. Median values of vitamin D and PTH in patients were 54.3 (IQR 21.1) ng/mL and 127.5 (IQR 183.1) pg/mL respectively. Compared to healthy controls, calcium ion level in patients was significantly lower (P = .001). On the contrary, phosphorous, vitamin D and PTH levels were not significantly different. Vitamin D and PTH levels had no significant correlation with serum ferritin levels (P = 0.147 and P = 0.2 respectively, while calcium ion level showed significant negative correlation with serum ferritin levels (r=-0.44, P=0.007).

Conclusion: Vitamin D and PTH levels have no significant correlation with serum ferritin level. The calcium ion level has a moderate negative correlation with serum ferritin level.