Vit D

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Vitamin D levels a factor in healthy lung function

A report published in the December 2005 issue of the journal Chest, the journal of the American College of Chest Physicians, revealed that higher levels of vitamin D are correlated with improved lung function compared to individuals whose levels of the vitamin are lower.

N Black, MB ChB, and Scragg, MB BS, PhD from the University of Auckland in New Zealand used data obtained in the Third National Health and Nutrition Examination Survey (NHANES III), which was conducted in the Untied States from 1988 to 1994. The current analysis involved 14,091 men and women aged 20 and older whose serum 25-hydroxyvitamin D levels were measured and who had undergone spirometry to assess lung function.

The duo found that participants whose vitamin D levels were in the top one-fifth of participants had a higher mean FEV1 (forced expiratory volume in the first second) and FVC (forced vital capacity) compared with those whose levels were in the lowest fifth. (FEV1 and FVC are measures which are used to evaluate lung function.) After adjustment for vitamin D supplement intake and other factors, the difference between the top fifth and the lowest fifth of vitamin D levels was 106 milliliters for FEV1 and 142 milliliters for FVC.

"Low levels of vitamin D have been associated with osteoporosis, hypertension, diabetes, and cancer," stated Dr Black, who was the study’s lead author. "Our research shows that vitamin D may also have a strong influence on lung health, with greater levels of vitamin D associated with greater and more positive effects on lung function.

“The difference in lung function between the highest and lowest quintiles of vitamin D is substantial and greater than the difference between former and nonsmokers,” he noted.

In an accompanying editorial, lind , MD, MPH, of Harvard Medical School’s Channing Laboratory commented, "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. However, further studies examining the relationship between vitamin D and lung function are warranted to identify who may benefit from such an intervention.”