December 13, 2005

Researchers Link Vitamin D to Healthier Lungs

By Susan Heavey

WASHINGTON -- Higher amounts of vitamin D could help make it easier to breathe, according to new findings released on Monday, offering possible good news for smokers, asthmatics and other people with respiratory problems.

Researchers at the University of Auckland in New Zealand found people with higher levels of the vitamin in their systems showed better lung function than those with lower amounts.

While the vitamin, which people get mostly from sunlight, is linked to lung health, the exact relationship is unclear, they said. Their findings appear in the December issue of the American College of Chest Physicians' journal, Chest.

Vitamin D can also be found in certain foods like fortified beverages and fatty fish like salmon and mackerel as well as dietary supplements.

"Although there is a definite relationship between lung function and vitamin D, it is unclear if increases in vitamin D through supplements or dietary intake will actually improve lung function in patients with chronic respiratory diseases," said Dr. Peter Black, who led the study.

Black, an associate professor in the university's Department of Medicine, and his team analyzed information from the U.S. National Health and Nutrition Examination Survey, which collected data on 14,091 people from 1988 to 1994.

Their new analysis found those who had higher levels of vitamin D were able to inhale and exhale more air.

That link was seen in blacks and non-Hispanic whites and was stronger in people older than 60 and smokers. Non-Hispanic blacks and Mexican-Americans showed lower levels of the vitamin compared to whites.

The study, funded by the Health Research Council of New Zealand, also found levels of the nutrient were higher among men and lessened as people aged or gained weight.

Dr. Rosalind Wright, a professor at Harvard Medical School's Department of Society, Human Development, and Health, said the vitamin could be an easy way to boost lung function.

"Vitamin D would be a relatively simple, low-cost intervention that would likely have high compliance to prevent or slow loss of lung function in susceptible subgroups," said Wright, who wrote in an editorial accompanying the study.

She added that more studies are needed to see who would benefit most.

Other recent studies have suggested Vitamin D may help strengthen bones as well as prevent some cancers and multiple sclerosis.