Vitamin D Deficiency May Limit Airflow COPD

— South Korean study explores effects on clinical characteristics of COPD patients.
by Parker Brown, Staff Writer, MedPage Today
April 21, 2015

South Korean researchers found abnormally low levels of the vitamin/hormone among patients with chronic obstructive pulmonary disease (COPD), and the levels didn’t change by season.

Almost 80% of the 193 patients in the study had vitamin D deficiency, and only 12 were categorized as normal, according to Ji Ye Jungopens in a new tab or window at Yonsei University College of Medicine in Seoul, and colleagues.

The investigators also found that vitamin D deficiency was significantly associated with airflow limitation.

“This is the first COPD cohort study that included repeated measurement of vitamin D levels and clinical consequences every year,” they wrote in the Respirology. “However, whether activation of the vitamin D pathway, by supplementation or other strategies, alters the disease course remains to be explored.”

No associations were found for quality of life, exacerbation, or emphysema with vitamin D levels. But there was a weak, nonsignificant association found between deficiency and a 6-meter distance test (P=0.069).

Data were taken from 17 hospitals. All participants were nonsmoking and older than age 40. Almost 30% had vitamin D levels that were severely deficient (<10 ng/mL). Researchers said a higher proportion of Korean patients with COPD have a deficiency compared with patients with COPD in other countries; they attributed this to the fact that the general population in South Korea has a higher level of deficiency than the population in other countries.

Patients had their blood drawn yearly, and seasonal variation was also tested for, but not found. That’s in contrast to several other studies, but the authors said that seasonal factors might not affect COPD patients.

“Vitamin D from sunlight might play a smaller role for patients with COPD, who spend relatively less time outdoors than the general population does,” the authors wrote.