Inclusion criteria | Exclusion criteria |
---|---|
Vitamin D deficiency (serum 25(OH)D < 50 nmol/l) | Severe vitamin D deficiency (serum 25(OH)D <15 nmol/l), |
Postbronchodilator FEV1/FVC < 0.70, FEV1 < 80 % and diagnosis COPD confirmed by a physician | Use of a supplement containing more than 400 IU vitamin D per day |
Recent COPD exacerbation | Use of maintenance dose oral corticosteroids |
≥10 packyears of smoking | Diagnosed asthma |
Age ≥ 40 years | Diagnosed osteoporosis |
Written informed consent | Self-reported history of hypercalcaemia or nephrolithiasis |
Ability to comply with all study requirements. | Self-reported presence of sarcoidosis |
 | Diagnosed chronic kidney disease stage 4 or higher (eGFR ≤ 29 ml/min/1.73 m2) |
 | Interfering malignant diseases |
 | Life expectation of less than 1 year on the basis of concurrent disease |
 | Current participation in a clinical rehabilitation program |
 | Pregnant or lactating women, or subjects who intend to become pregnant within the study period |
 | Potentially unreliable patients and those judged by the investigator to be unsuitable for the study |
 | Serious mental impairment i.e. preventing to understand the study protocol or comply with the study aim |