Onderzoek naar de effecten van vitamine D op de longfunctie, luchtweginfecties en lichamelijke conditie bij COPD-patiënten.

Rationale:

Although vitamin D is well known for its function in calcium homeostasis and bone mineralisation, several studies have shown an effect on pulmonary function and incidence of airway infections. Vitamin D deficiency is a common problem in patients with COPD. As vitamin D deficiency is associated with impaired pulmonary function and a higher incidence of airway infections, supplementation with vitamin D might have positive effects on these outcomes in patients with COPD.



Objective:

To assess the effect of vitamin D supplementation on pulmonary function, the incidence of airway infections and physical performance in patients with COPD.



Study design:

Double-blind placebo-controlled intervention study.



Study population:

The study population will include 120 patients with COPD, aged between 40 and 75 years, who will be randomly allocated to one of two groups.



Intervention:

The intervention group will receive vitamin D3 1200 IU orally once a day. The control group will receive a placebo orally once a day.



Main study parameters/endpoints:

The main study parameters are the serum concentration 25-hydroxyvitamin D, the pulmonary function parameters FEV1 and FVC, the incidence of airway infections, the scores on the physical performance tests and the scores on the LASA physical activity questionnaire (LAPAQ).



Methods:

During the study there will be three visits. Measurements will be conducted at baseline before randomisation (t=0), at 3 months (t=3) and at 6 months (t=6) after randomisation. During every visit the patients will undergo spirometry, a blood sample will be drawn, a questionnaire on functional limitations will be filled in, and physical performance tests will be done. The participants will also receive a diary card to register the incidence of airway infections during the study period.

Although vitamin D is well known for its function in calcium homeostasis and bone mineralisation, several studies have shown an effect on pulmonary function and incidence of airway infections. Vitamin D deficiency is a common problem in patients with COPD. As vitamin D deficiency is associated with impaired pulmonary function and a higher incidence of airway infections, supplementation with vitamin D might have positive effects on these outcomes in patients with COPD.

During the study there will be three visits. Measurements will be conducted at baseline before randomisation (t=0), at 3 months (t=3) and at 6 months (t=6) after randomisation. During every visit the patients will undergo spirometry, a blood sample will be drawn, a questionnaire on functional limitations will be filled in, and physical performance tests will be done. The participants will also receive a diary card to register the incidence of airway infections during the study period.

The intervention group will receive vitamin D3 1200 IU orally once a day. The control group will receive a placebo orally once a day.