Personal behaviors including food consumption and mineral supplement use among Japanese adults: a secondary analysis from the National Health and Nutrition Survey, 2003-2010

Background and Objectives: A daily mineral supplement is useful for those who are at risk of a deficiency. Some Western reports suggest that mineral supplement users have healthy behaviors and are not mineral-deficient. It is unknown whether the same phenomenon is observed in Japan where there is a different dietary culture. The aim of this study was to examine the characteristics of personal behaviors including food consumption nationwide among mineral supplement users from the National Health and Nutrition Survey in Japan 2003-2010. Methods and Study Design: Data were obtained from 16,275 adults aged 20-59 years who completed socio-demographic, health status, and 1-day household dietary assessments. Supplement users were compared with non-users. Logistic regression models were utilized to identify the characteristics of food consumption and calcium and iron supplement use, using the medium intake group as a reference. Results: Overall, 2.1% and 1.4% of adults reported using calcium supplements and iron supplements, respectively. Calcium supplement users were more likely to be physically active, non-smokers, and eat less fat compared with non-users. Furthermore, they were more likely than non-users to consume a higher intake of calcium from foods such as tea, vegetables, sea weeds, and fruits. Iron supplement users were more likely than non-users to be non-smokers. These individuals tended to have a high intake of seaweeds and fruits. Conclusions: Japanese adults who had healthier behaviors were more likely to use mineral supplements, especially calcium. Mineral supplement users tended to choose healthy foods such as seaweeds and fruits, without considering their overall mineral consumption.