1. Tromsø Endocrine Research Group; Institute of Clinical Medicine; UiT The Arctic University of Norway; Tromsø Norway
2. Division of Internal Medicine; University Hospital of North Norway; Tromsø Norway
3. Department of Health and Care Sciences; UiT The Arctic University of Norway; Tromsø Norway
4. Cork Centre for Vitamin D and Nutrition Research; School of Food and Nutritional Sciences; Cork Ireland
5. Department of Medicine; University College Cork; Cork Ireland