Vitamin D deficiency is associated with worse lung function and more rapid decline in lung function over time in smokers, suggesting the vitamin may have a protective effect against the effects of smoking on lung function, according to a study of white men.
Nancy E. Lange, MD, MPH, of the Channing Laboratory at Brigham and Women’s Hospital in Boston, and colleagues "examined the relationship between vitamin D deficiency, smoking, lung function and the rate of lung function decline over a 20-year period in a cohort of 626 adult white men from the Normative Aging Study," according to a news release.
The researchers found that vitamin D sufficiency — defined as serum vitamin D levels of more than 20 nanograms per milliliter — "had a protective effect on lung function and the rate of lung function decline in smokers,’ Lange said in the news release.
In the study, vitamin D levels were assessed at three different time points between 1984 and 2003, and lung function was assessed concurrently with spirometry.
In vitamin D-deficient subjects, for each one-unit increase in pack-years of smoking, average forced expiratory volume in one second (FEV1) was 12 milliliters lower, compared with an average reduction of 6.5 ml among subjects who were not vitamin D deficient. In longitudinal models, vitamin D deficiency exacerbated the effect of pack years of smoking on the decline in FEV1 over time.
No significant effect of vitamin D levels on lung function or lung function decline was observed in the overall study cohort, which included both smokers and nonsmokers.
"Our results suggest that vitamin D might modify the damaging effects of smoking on lung function," Lange said. "These effects might be due to vitamin D’s anti-inflammatory and anti-oxidant properties."
The researchers noted limitations in the study, including that the data was observational only and not generated through a trial, that vitamin D levels fluctuate over time and that the study has limited generalizability because the cohort was all elderly men.
"If these results can be replicated in other studies, they could be of great public health importance," Lange said. "Future research should also examine whether vitamin D protects against lung damage from other sources, such as air pollution."
"While these results are intriguing, the health hazards associated with smoking far outweigh any protective effect that vitamin D may have on lung function," said Alexander C. White, MD, MS, chairman of the American Thoracic Society’s Tobaacco Action Committee. "First and foremost, patients who smoke should be fully informed about the health consequences of smoking and in addition be given all possible assistance to help them quit smoking."
The findings appeared July 19 on the website of the American Journal of Respiratory and Critical Care Medicine, a publication of the American Thoracic Society. To read the study abstract and access the study via subscription or purchase, visit http://bit.ly/QgADGI.
Nancy E. Lange, MD, MPH, of the Channing Laboratory at Brigham and Women’s Hospital in Boston, and colleagues "examined the relationship between vitamin D deficiency, smoking, lung function and the rate of lung function decline over a 20-year period in a cohort of 626 adult white men from the Normative Aging Study," according to a news release.
The researchers found that vitamin D sufficiency — defined as serum vitamin D levels of more than 20 nanograms per milliliter — "had a protective effect on lung function and the rate of lung function decline in smokers,’ Lange said in the news release.
In the study, vitamin D levels were assessed at three different time points between 1984 and 2003, and lung function was assessed concurrently with spirometry.
In vitamin D-deficient subjects, for each one-unit increase in pack-years of smoking, average forced expiratory volume in one second (FEV1) was 12 milliliters lower, compared with an average reduction of 6.5 ml among subjects who were not vitamin D deficient. In longitudinal models, vitamin D deficiency exacerbated the effect of pack years of smoking on the decline in FEV1 over time.
No significant effect of vitamin D levels on lung function or lung function decline was observed in the overall study cohort, which included both smokers and nonsmokers.
"Our results suggest that vitamin D might modify the damaging effects of smoking on lung function," Lange said. "These effects might be due to vitamin D’s anti-inflammatory and anti-oxidant properties."
The researchers noted limitations in the study, including that the data was observational only and not generated through a trial, that vitamin D levels fluctuate over time and that the study has limited generalizability because the cohort was all elderly men.
"If these results can be replicated in other studies, they could be of great public health importance," Lange said. "Future research should also examine whether vitamin D protects against lung damage from other sources, such as air pollution."
"While these results are intriguing, the health hazards associated with smoking far outweigh any protective effect that vitamin D may have on lung function," said Alexander C. White, MD, MS, chairman of the American Thoracic Society’s Tobaacco Action Committee. "First and foremost, patients who smoke should be fully informed about the health consequences of smoking and in addition be given all possible assistance to help them quit smoking."
The findings appeared July 19 on the website of the American Journal of Respiratory and Critical Care Medicine, a publication of the American Thoracic Society. To read the study abstract and access the study via subscription or purchase, visit http://bit.ly/QgADGI.
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