Background/Aims:Dietary composition has been shown to affect acid-base homeostasis and bone health in humans. We investigated the potential renal acid load (PRAL) and the estimated diet-dependent net acid load (net endogenous acid production, NEAP) in adult vegans and evaluated the relationships between NEAP, food groups and intake of bone health-related nutrients. Methods: The German Vegan Study (GVS) is a cross-sectional study. Data from healthy men (n = 67) and women (n = 87), aged 21–75 years, who fulfilled the study criteria (vegan diet for ≧1 year prior to study start; age ≧18 years, and no pregnancy/childbirth during the last 12 months) were included in the analysis. NEAP values were calculated from diet composition using two models: one based on the protein/potassium quotient and another taking into account an anthropometry-based loss of urinary organic anions. Results:Mean daily intakes of phosphorus, potassium, sodium, magnesium and vitamin C were above, and vitamin D and calcium below Dietary Reference Intake (DRI). Regardless of the model used, the diet in the GVS was characterized by a nearly neutral NEAP. A strong correlation was observed between the NEAP values of the two models (rs = 0.873, p < 0.001). Only the consumption of fruits decreased constantly across the increasing quartiles of NEAP. Conclusions: It can be hypothesized that vegan diets do not affect acid-base homeostasis. With respect to bone health, the significance of this finding needs further investigation.