Nancy E. Lange, M.D., M.P.H., from Brigham and Women's Hospital in Boston, and colleagues examined the effect of vitamin D deficiency and smoking on lung function for 626 men participating in the Normative Aging Study. Spirometry and 25-hydroxyvitamin D levels were measured at three different time points between 1984 and 2003. Data were assessed 20 years after enrollment.

The researchers found that, in the overall cohort, vitamin D deficiency (serum level ≤20 ng/mL) had no significant effect on lung function or on lung function decline. However, in multivariable analysis, vitamin D status had an effect modification on the association between smoking and lung function. Current smokers with vitamin D deficiency had significantly lower lung function (forced expiratory volume in one second [FEV]), forced vital capacity [FVC], and FEV1/FVC). In addition, the rate of decline in FEV1 was significantly more rapid per pack-year of smoking, compared to individuals who were vitamin D sufficient.

"Our results suggest that vitamin D might modify the damaging effects of smoking on lung function," Lange said in a statement. "These effects might be due to vitamin D's anti-inflammatory and anti-oxidant properties."

Abstract
Full Text (subscription or payment may be required)