Background: Vitamin D (Vit D) is linked to various conditions including musculoskeletal, metabolic and   cardiopulmonary diseases. However, it is not clear whether correction of vit D deficiency exerts any beneficial effect in patients with pulmonary hypertension.

Methods: This study was a prospective uncontrolled longitudinal study. Patients with pulmonary hypertension and vit D deficiency were enrolled into this study. All patients in addition to standard treatment for pulmonary hypertension received cholecalciferol at a dose of 50,000 IU weekly plus calcicare (at a dose of 200 mg magnesium + 8 mg zinc + 400 IU vit D) daily for 3 months. Serum level of 25-hydroxy vit D, serum level of pro-brain natriuretic peptide, six minute walk test (6MWT), peak and mean pulmonary artery pressure, right ventricular size and function, ejection fraction (EF) and New York Heart Association (NYHA) functional class were measured at baseline and after 3 months of treatment.

Results: Twenty-two patients with pulmonary hypertension and vit D deficiency were enrolled into the study. At endpoint, the serum vit D level increased significantly to 54.8 ng/ml, the mean of baseline distance of 6MWT increased significantly to 81.6 m and the RV size significantly improved. The mean pulmonary artery pressure also improved after the intervention, but their changes did not reach to statistically significant levels.

Conclusion: Vit D replacement therapy in patients with pulmonary arterial hypertension and vit D deficiency results in significant improvement of right ventricular size and 6 MWT. Moreover, mean pulmonary artery pressure improves nonsignificantly. This issue requires further studies with long-term follow-up period.