The objective was to assess the prevalence of inadequate micronutrient intake in a representative sample of the French population, which to our knowledge, had never been done before, and to use this concept to optimize efficiency and safety of food fortification. The INCA survey collected food intake data using a 7-day record, for 2373 subjects (4-92 years). The prevalence of inadequacy for calcium, magnesium, iron, vitamins C, A, B6, and B12, thiamin, riboflavin, niacin, pantothenic acid, and folate was estimated by the proportion of subjects with intake below the Estimated Average Requirement (EAR). We also calculated daily consumption of 44 food groups by age and gender. This paper shows how the combination of both data sets, i.e., inadequacy and food consumption data, allows a preliminary screening of potential food vehicles in order to optimize fortification. The prevalence of inadequacy was particularly high for the following groups: for calcium, females aged 10-19 years (73.5%) or aged 55-90 years (67.8%), and males aged 15-19 years (62.4%) or aged 65-92 years (65.4%); for magnesium, males aged 15-92 years (71.7%) and females aged 10-90 years (82.5%); for iron, females aged 15-54 years (71.1%); and for vitamin C, females aged 15-54 years (66.2%). Two examples are provided to illustrate the proposed method for the optimization of fortification.