This study investigated the prevalence of inadequate micronutrient intake and the proportion of subjects who exceed Tolerable Upper Intake Levels a) with food only, and b) with food+supplements, in a population of French regular supplement users (n = 259). Assessment tools were seven-day records for supplements, three-day records for food intake, and a questionnaire about supplement use. Most subjects were recruited in retail outlets that sold supplements. They were recent users of vitamin/mineral supplements, aged over 15 years, and normo-energy reporters. The prevalence (%) of inadequate intake decreased with the inclusion of mean annual supplements, from 68.0 to 54.8 for magnesium, 55.9 to 40.7 for vitamin C, 53.4 to 43.9 for folic acid, 37.5 to 27.5 for iron, and 40.1 to 29.7 for pantothenic acid. Few subjects exceeded upper intake levels when mean annual intake of supplements was considered. When supplement consumption was considered during the studied week only, the proportion of subjects who were in excess of the upper intake levels was higher (maximum: 9.6% for magnesium). Supplement use brought a nutritional benefit for some targeted nutrients. It was not associated with excessive intake in this study, but could become hazardous if the annual frequency of use were to increase.
