Khayyatzadeh SS, et al. - This cross-sectional study was carried out to examine the association between lifestyle patterns, liver functional tests (LFTs), and the presence of irritable bowel syndrome (IBS) with serum 25-hydroxy vitamin D (25-OH D) in apparently healthy girls. Significantly lower serum 25-OH D concentrations were noted in individuals with IBS. Furthermore, an inverse association was observed between serum alanine transaminase (ALT) and 25-OH D. To clarify these associations, prospective studies, and perhaps interventional trials would be required.