The postulated medical benefits of vitamin D continue unabated. Every week, there is a new study which shows that vitamin D can cure an illness.
For some time researchers have been postulating that people who smoke and have exacerbations of their COPD may be vitamin D deficient. Some people with COPD have been found to have a deficiency of vitamin D but it is not known if this is due to a poor diet or a result of the COPD.
Thus, vitamin D supplementation has been proposed to treat patients who have COPD and other related manifestations.
Some health care workers have empirically been treating their COPD patients with vitamin D without first determining if they have a deficiency. The belief that vitamin D is an all-purpose supplement with far-reaching medical benefits has made it one of the most widely consumed substances.
But does it work?
Now there is a study which debunks that myth. In the latest study from Belgium, monthly doses of 1000,000 IU ( 3,200 IU daily) had almost no effect in reducing or preventing the exacerbations of COPD. (1)
The researchers measured levels of vitamin D in blood and observed that Individuals who had normal levels of vitamin D had no benefit.
The benefit of vitamin D was only seen in patients who had a deficiency. In COPD individuals without a deficiency of vitamin D, there was no improvement in quality of life or symptoms.
Based on this study, the recommendations included that clinicians first assess vitamin D levels in blood. The supplement is only of benefit in patients with a known deficiency. (2)
It also has to be understood that taking large doses of vitamin D can lead to hypercalcemia. For most people, the upper limit of tolerability is about 4,000 IU per day, but even this dose may be too high for elderly and sick individuals.
While vitamin D may be of some benefit in improving chronic airway disease, finding the right patient and right dose is vital.
For the moment, vitamin D is useful for the treatment of osteoporosis in postmenopausal women. Its role in the treatment of COPD is still debated.