Low levels of vitamin D are associated with an increased risk of a type of rare lung disease, researchers are reporting. In a review of medical information gathered from more than 6,000 adults over a 10-year-period, researchers found that lower than normal levels of vitamin D were linked to an increased risk of early signs of interstitial lung disease, a relatively rare condition characterized by lung scarring and inflammation that can cause permanent lung damage and shorten lifespans. It has no proven treatment or cure. The finding may help guide future strategies to prevent the condition and suggests that adequate levels of vitamin D may be important for lung health, they say. The study, which is partly funded by NHLBI, appears in the Journal of Nutrition.