Vitamin D Supplementation and Reduction of Severity and Frequency of Epistaxis in Hereditary Haemorrhagic Telangiectasia

1. Purpose:

The focus of the study is to determine if supplementing vitamin D in patients diagnosed with HHT will reduce the frequency and severity of epistaxis episodes. 2. Hypothesis:

For patients diagnosed with HHT, daily vitamin D supplementation will reduce the frequency and severity of epistaxis. Additionally, there will be a greater reduction in epistaxis frequency and severity the larger the dose of daily vitamin D supplemented 3. Justification:

Hereditary haemorrhagic telangiectasia (HHT) is a rare autosomal dominant inherited disorder of the fibrovascular tissue that causes malformation of capillaries (called "telangiectases") and/or larger blood vessels (called "arteriovenous malformations") throughout the body. The formation of these lesions ultimately result in patients experiencing increased tendency for bleeding. These lesions may present in varying locations systemically, however recurrent and severe epistaxis is the most common presentation of HHT.

Various medical and surgical treatments exist for management of HHT patients which are aimed at decreasing the frequency and severity of epistaxis episodes. These therapies include: humidification, nasal lubrication, nasal hot saline irrigation, intranasal packing, oestrogen ointment, tranexamic acid, bevacizumab systemic/topically applied, use of propranolol to lower blood pressure, electrocautery and YAG laser. Although all these various options are available, there currently is no consensus toward an optimal solution. Treatment can become especially difficult due to progressive anaemia or when anticoagulant or anti-thrombotic therapy becomes necessary. Therefore, there is a need for establishment of a safe and effective therapy.