Objective: Serum diamine oxidase (DAO) activity varies to a greater extent in women than in men. DAO activity during the luteal phase was higher than that during the follicular phase in healthy women. Recent reports have indicated that duodenal lipid infusion increased DAO activity in the intestinal lymph in rats. The aim of this study was to elucidate the effect of dietary nutrient intake on serum DAO activity in healthy women.Methods: Thirty-four healthy Japanese women were recruited. Food surveys were performed using dietary records for 3 d during both the follicular and luteal phases. Nutrient intake was calculated and expressed as the energy intake ratio. The correlation between DAO activity and nutrient intake was analyzed.Results: Serum DAO activity in both phases was positively correlated with intake of long-chain fatty acids, saturated fatty acids, and monounsaturated fatty acids (P < 0.05). Intake of phosphorus, calcium, zinc, magnesium, iron, and vitamin B-12 during the luteal phase was positively correlated with serum DAO activity (P < 0.05).Conclusion: In healthy women, serum DAO activity was influenced by dietary fatty acid and micronutrient intake. (C) 2017 Elsevier Inc. All rights reserved.