Fibrosing interstitial pneumonias are associated with various stages of fibrosis. The cause of this group of syndromes remains largely unknown. For most of these diseases, a genetic basis, environmental factors and certain triggers have been suggested as possible risk factors. Various studies have found an association between genetic polymorphisms, or the presence of certain variant alleles, and the occurrence and/or progression of interstitial pneumonias of unknown origin. An acute exacerbation of idiopathic pulmonary fibrosis shows characteristics of diffuse alveolar haemorrhage (DAH). DAH can be aggravated by vitamin K deficiency. This review deals with pharmacogenetic factors underlying interindividual differences of vitamin K status in patients with interstitial pneumonias and the possibilities for a personalized approach to patient management.