Http://www.med.nu.ac.th/index.php?a%5B%5D=%3Ca+href%3Dhttps%3A%2F%2Fwww.copdfoundation.org%2FCOPD360social%2FCommunity%2FQuestions-and-Answers%2FVitamins-for-COPD.aspx%3EReturn+to+previous+pa