"The results of dozens of scientific studies into the effects of smoking on the lungs are conclusive Cigarette smoking is the No.  risk factor httpshealth.usnews.comhealthcarepatientadvicearticleswhataretheriskfactorsforcopd for developing chronic obstructive pulmonary disease httpshealth.usnews.comconditionscopd. COPD is as the name suggests a chronic lung disease that makes it progressively harder to breathe. Although patients currently have several treatment options httpshealth.usnews.comhealthcarepatientadvicearticleswhatarethecurrenttreatmentstandardsforcopd available to help manage the disease  whose name is an umbrella term encompassing both emphysema and chronic bronchitis  there is no cure. Although its clear that exposure to cigarette smoke is a major cause of COPD its not the only cause and scientists still arent sure exactly how cigarette smoke and other inhaled irritants can trigger the development of COPD. One working theory is that smoking cigarettes depletes the body of vitamin A a nutrient that the lungs use to repair themselves. See  Lifestyle Tips to Manage Your Asthma httpshealth.usnews.comhealthnewspatientadviceslideshowslifestyletipstomanageyourasthma.  The National Institutes of Health reports that Vitamin A is the name of a group of fatsoluble retinoids including retinol retinal and retinyl esters. Its involved in maintaining the immune system vision reproduction and communication between cells. Vitamin A also supports cell growth and differentiation playing a critical role in the normal formation and maintenance of the heart lungs kidneys and other organs. Vitamin A enters the discussion with COPD because the body uses vitamin A to build and repair lung tissue. Dr. Antonello Punturieri program director for chronic obstructive pulmonary diseaseenvironment at the National Heart Lung and Blood Institute says the connection between vitamin A and the lungs starts from the very beginning while were developing in utero and continues well into adulthood. The lungs are still developing until age  or . This is why teen smoking is so bad he says. Having an adequate vitamin A intake throughout this developmental period is critical to developing and maintaining strong healthy lungs he says.   httpshealth.usnews.comhealthnewshealthwellnessarticlesisavitaminormineraldeficiencymakingyoutiredIs a Vitamin or Mineral Deficiency Making You Tired httpshealth.usnews.comhealthnewshealthwellnessarticlesisavitaminormineraldeficiencymakingyoutired Why you should sit up and take notice of your nagging fatigue. Michael O. SchroederSept.   But if our lungs dont have enough vitamin A to build or repair themselves that could potentially lead to lung infections or chronic diseases of the lungs. A  study in the journal Molecular Aspects of Medicine https explains that during moderate vitaminAdeficiency the incidence for diseases of the respiratory tract is considerably increased and repeated respiratory infections can be influenced therapeutically by a moderate vitaminAsupplementation. In addition to the importance of the vitamin for the lung function vitaminA is also responsible for the development of many tissues and cells as well as for the embryonic lung development. See  Questions to Ask Your Pharmacist httpshealth.usnews.comhealthnewspatientadviceslideshowsquestionstoaskyourpharmacist. Another study conducted in Nepal and published in the New England Journal of Medicine http in  also found that pregnant women whod taken vitamin A supplements during pregnancy had children with better lung health when the researchers followed up  to  years later. Early interventions involving vitamin A supplementation in communities where undernutrition is highly prevalent may have longlasting consequences for lung health the authors concluded. So it seems clear that vitamin A plays a role in lung health. To further investigate this connection researchers in Holland bred laboratory mice to have reduced but not deficient levels of vitamin A. In their  study published in the Journal of Physiology and Pharmacology http_pdf___article.pdf the researchers then exposed these mice to cigarette smoke and observed that the mice developed emphysema in just three months. Although the study was done in mice and human physiology is different there could be some implications here for the interaction of cigarette smoke vitamin A levels and the development of chronic lung diseases. One of these hopedfor implications is a way to reverse or cure the lung damage that results in COPD. Way back in  researchers at the Georgetown University School of Medicine showed that retinoic acid a derivative of vitamin A reversed emphysema in the lungs of lab rats. The treatment restored lung alveoli  the small air sacs in the lungs that move oxygen and carbon dioxide into and out of the blood  to normal size and number. These spaces tend to become overinflated in patients with emphysema so the results of that particular study were encouraging in advancing the idea of using vitamin A as a possible treatment for emphysema and COPD. But in a press release from the NHLBI study coauthor Dr. Donald Massaro urged caution. A great deal more basic research is needed before we can even begin to think about applying this to humans. Until then we caution that there is absolutely no evidence that Vitamin A supplementation is useful in treating lung disorders. Investigations continue but currently theres still not enough evidence to support the idea that supplementing your diet with vitamin A is going to have a big impact on COPD symptoms or the progression of the disease. Still its an important micronutrient that you should seek to include in your diet httpshealth.usnews.comhealthnewspatientadvicearticlescopdthenutritionconnection. Although most Americans are not deficient in vitamin A  the Centers for Disease Control and Prevention reports that less than  percent of the population is deficient in vitamin A  the Mayo Clinic currently recommends that adult men  years and older should seek to take in  micrograms  international units of vitamin A daily. Women age  and older should aim for  micrograms  IU daily. Pregnant and nursing woman may need more vitamin A. See  Things You Didnt Know About Lung Cancer httpshealth.usnews.comhealthnewspatientadviceslideshowsthingsyoudidntknowaboutlungcancer. Vitamin A can be found in most multivitamins and in dairy products liver fortified foods fish and darkly colored fruits and vegetables. Five servings of fruits and vegetables daily supplies  to  milligrams of provitamin A carotenoids which provides about  to  percent of the adult recommend dietary allowance for vitamin A the Mayo Clinic reports. However a word of caution if youre planning to add a vitamin A supplement to your diet httpshealth.usnews.comhealthcarepatientadvicearticlesshouldiusedietarysupplementsformycopd Because vitamin A is a fatsoluble vitamin it can build up in your system and its possible to overdose on it. Symptoms of vitamin A toxicity may include changes in vision or the skin abdominal pain and bone pain. Chronic toxicity can cause liver damage as excess amounts of vitamin A are stored in the liver. It may also lead to osteoporosis and kidney damage so be careful not to overdo it with vitamin A supplements if you opt to take them. Best Hospitals for Pulmonology Rank Hospital Name Location       National Jewish Health DenverUniversity of Colorado Hospital httpshealth.usnews.combesthospitalsareaconationaljewishhealthDenver CO    Mayo Clinic httpshealth.usnews.combesthospitalsareamnmayoclinicRochester MN    Cleveland Clinic httpshealth.usnews.combesthospitalsareaohclevelandclinicCleveland OH    Massachusetts General Hospital httpshealth.usnews.combesthospitalsareamamassachusettsgeneralhospitalBoston MA    UPMC Presbyterian Shadyside httpshealth.usnews.combesthospitalsareapaupmcuniversityofpittsburghmedicalcenterPittsburgh PA    UCSF Medical Center httpshealth.usnews.combesthospitalsareacaucsfmedicalcenterSan Francisco CA    University of Michigan Hospitals and Health Centers httpshealth.usnews.combesthospitalsareamiuniversityofmichiganhospitalsandhealthcentersAnn Arbor MI    BarnesJewish Hospital httpshealth.usnews.combesthospitalsareamobarnesjewishhospitalwashingtonuniversitySaint Louis MO    Penn Presbyterian Medical Center httpshealth.usnews.combesthospitalsareapapennpresbyterianmedicalcenterPhiladelphia PA    UCLA Medical CenterSanta Monica httpshealth.usnews.combesthospitalsareacauclamedicalcentersantamonicaSanta Monica CA   Hospital Ranking information as of October th  Elaine K. Howley https Contributor Elaine Howley began writing for U.S. News in  covering breast cancer and COPD. Since then...  Read more Tags patients https patient safety https_safety COPD chronic obstructive pulmonary disease https vitamins https respiratory problems https_problems patient advice https"