A method of treating disorders in which DHA levels are affected is described. The method includes administering to a subject suffering from the disorder a therapeutically affective amount of DHA. This method is particularly useful in treating subjects suffering from a disorder characterized by a defect in the CF, gene, e.g. cystic fibrosis, or a chronic inflammatory disorder, e.g., ulcerative colitis, Crohn's disease, chronic pancreatitis, asthma, rheumatoid arthritis or chronic gastritis. A method of ameliorating affects of cystic fibrosis in a newborn and a method of increasing surfactant levels in a fetus are also described.