Previous studies have shown that there is a large inter-individual variability in the degree of bone loss during glucocorticoid treatment, and while some patients experience extensive bone loss other patients' bone mass remains stable. The aim of the study is to find a biomarker that can be used to identify individuals at risk of glucocorticoid-induced bone loss. The study will include 36 healthy volunteers, that will be randomized to receive either glucocorticoid treatment or placebo. During the study blood samples, bone marrow samples, bone tissue samples, and adipose tissue samples are taken and an oral glucose tolerance test is performed.

Inclusion Criteria:

• Men and women aged 18-50 years.

Exclusion Criteria:

• Uncontrolled thyrotoxicosis
• Chronic kidney disease (eGFR <30)
• Known Cushing's syndrome
• Previous gastric bypass and/or known ongoing malabsorption
• Severe covid-19 in the last 3 month (defined as needing dexamethasone treatment)
• Use of oral or inhaled glucocorticoids within the past year
• Menopause (defined as 1 year without menstrual bleeding)
• Pregnancy (defined as elevated HCG)
• Ongoing infection
• Allergy to prednisolone or one of the excipients
• Systematic fungal infections
• Vaccination with living or weaken viral or bacterial vaccines in patient who or immunocompromised. In these cases, prednisolone treatment should not be administered two weeks before and after vaccination
• Not able to provide informed consent (e.g., dementia, not able to understand Danish).

Individual participant data will not be shared with other researchers other than collaborators. Since the data contains personal information from the study participants