Efficacy of High Dose Vitamin D on Pulmonary Artery Pressure in Thalassemia Patients Undergoing Blood Transfusion: A Randomized Trial

Background: Pulmonary arterial hypertension (PAH) may result in cardiomyopathy which is a major cause of death in thalassemia patients. Vitamin D is associated with benefits in cardiovascular disorders. Our purpose was to study effects of vitamin D on pulmonary artery pressure in thalassemia major and intermedia patients. Materials and Methods: This randomized trial was performed on 26 patients with thalassemia major (TM) and intermedia (TI) in Amir-Kabir Hospital, Arak, Iran in 2019-2020. Patients were randomized 1:1 to intervention group (vitamin D 50,000 IU/week) and control group (received no supplement) for 20 weeks. Echocardiography was used to measure pulmonary artery pressure and assess cardiovascular function. The levels of 1,25-dihydroxyvitamin D3, ferritin, and cardiac iron content were measured in study groups. Results: After 20 weeks, pulmonary arterial pressure (PAP), tricuspid regurgitant velocity (TRV), and pulmonary regurgitant velocity (PRV) significantly improved in the intervention group compared to the control group (P= 0.010, P= 0.003, and P= 0.001, respectively). Moreover, ejection fraction (EF) had significant increase in the intervention group compared to the control group (P= 0.008), although vitamin D supplementation had no significant impact on cardiac T2* values (P= 0.827), systolic and diastolic blood pressure (P= 0.388 and P= 0.509, respectively) and serum hemoglobin and ferritin levels (P= 0.557 and P= 0.620) as compared to the control group. However, the levels of 25-OHD3 significantly increased in the intervention group compared to the control group (P= 0.036). Conclusion: This study showed that vitamin D 50000 IU/week can improve PAP in patients with thalassemia. Sufficient intake of vitamin D may prevent cardiomyopathies related to PAH.