D-vitamin And Graves' Disease; Morbidity And Relapse Reduction

The DAGMAR Study. D-vitamin And Graves' Disease; Morbidity And Relapse Reduction: A Randomised, Clinical Trial.

The purpose of this study is to investigate the effects of vitamin D supplementation on morbidity and risk of relapse in patients with Graves' disease.

In a multicentre trial, 260 patients with newly diagnosed Graves ' disease will be randomized to cholecalciferol 70 mcg/day or placebo in a parallel Group design. Drop outs prior to 31th of December 2017 will be replaced. The intervention will continue during treatment with antithyroid drugs (ATD), and for a period of 12 months after cessation of ATD. Blood samples will be collected at study entry, at 3 and 9 months, and at end of study. QoL questionnaires on nine occasions through out the study period. In a subcohort of 80 participants detailed examinations of bone density and geometry, muscle strength and postural balance, immune tests (N=50), and measurements of arterial stiffness will be performed at study entry, and at 3 and 9 months after randomisation.

Inclusion Criteria:

• A first time diagnosis of Graves' hyperthyroidism within the last three months, confirmed by TSH below 0.01 IU/L, and T3 or T4 levels above the reference interval necessitating ATD therapy
• Positive TRAb
• Speak and read Danish
• Written informed consent

Exclusion Criteria:

• Previously diagnosed hyperthyroidism
• ATD treatment initiated more than 3 months prior to inclusion
• Planned ablative therapy (radioactive iodine or thyroid surgery)
• Intake of more than 10 µg D-vitamin/day that the participant wishes to continue.
• Chronic granulomatous illness
• Persistent hypercalcemia (plasma calcium > 1.40 mmol/L)
• Reduced kidney function (eGFR < 45 ml/min)
• Treatment with immunomodulatory drugs
• Active malignant disease
• Alcohol or drug abuse
• Pregnancy at inclusion
• Major comorbidity, making the participant unlikely to continuously receive trial intervention.
• Allergy towards the components in the D-vitamin or the placebo pills.
• Unable to read and understand Danish
• Lack of informed consent.