Research brief

High dose vitamin D may boost exercise capacity for lung disease patients

High dose supplements of vitamin D may increase the exercise capacity and strength of respiratory muscles in people with chronic obstructive pulmonary disease (COPD), suggests a new study.

A monthly dose of a whopping 100,000 IUs (international units) of vitamin D experienced significant improvements in exercise capacity and respiratory muscle strength compared to those in the placebo group, according to findings presented at the ATS 2011 International Conference in Denver.

US recommendations for vitamin D are 600 IUs per day for adults up to age 70 and 800 IUs daily over 70 year-olds.

"Low levels of vitamin D in the blood have been related with muscle weakness, a major target for respiratory rehabilitation and increased risk of falls," said Miek Hornikx from the Katholieke Universiteit Leuven in Belgium.

"These results support the idea that correcting vitamin D deficiency by adding vitamin D supplements to training programs allows COPD patients to achieve better results from rehabilitation, including improvements in muscle strength and exercise capacity," she added.

D plus standard rehabilitation

COPD mainly affects smokers, and is the number five cause of deathworldwide. It is characterised by chronic inflammation in the small airwaysof the lung and leads to excessive mucus production, excessive fibrousconnective tissue development (fibrosis), and degradation of proteins (proteolysis). There is no cure.

Since vitamin D deficiency is common among patients with COPD the Belgian researchers tested the effects of a high-dose vitamin D supplement versus placebo in 50 COPD patients.

After three months of supplementation combined with a pulmonary rehabilitation program, the researchers reported that subjects in the vitamin D group had a significant improvement in exercise capacity and respiratory muscle strength, compared with the placebo group.

"Our study shows that high doses of vitamin D supplementation on top of a standard rehabilitation program improve the outcome in terms of exercise capacity and respiratory muscle strength," said Hornikx.

Source: ATS 2011 International Conference
Colorado Convention Center; Abstract 17477
"Vitamin D Supplementation During Rehabilitation In Patients With Chronic Obstructive Pulmonary Disease: An Intervention Study"