Patients with diagnosis of Pulmonary Arterial Hypertension of the following types according to 2022 ERS/ESC guidelines: idiopathic research hub

REstoration with calcifediol of VItamin D deficiency in pulmonary Arterial Hypertension patients (REVIDAH study)

This study looks at how vitamin D supplements (calcifediol) might help people in the UK with a specific type of high blood pressure in their lungs, called Pulmonary Arterial Hypertension (PAH). Researchers want to see if it improves their health and if it's safe.