Food insecurity is a public health problem as it affects a wide array of individuals in the population. It can be characterized by food deprivation, lack of essential nutrition, lack of dietary education, lack of adequate storage conditions, poor absorption, and poor overall nutrition. The relationship between food insecurity and micronutrient deficiency requires more effort to deepen and discuss the relationship. This systematic review aimed to evaluate the association between food insecurity and micronutrient deficiency in adults. The research was conducted according to PRISMA using the Medline/Pubmed, Lilacs/BVS, Embase, Web of Science, and Cinahl databases. Studies carried out with male and female adults were included, which investigated the correlation or association between food insecurity and the nutritional status of micronutrients. There were no publication year, country, or language restrictions. A total of 1148 articles were found, and 18 of these were included, carried out mainly on the American continent and with women. The most evaluated micronutrients were iron and vitamin A. Food insecurity was associated with nutrient deficiency in 89% (n = 16) of the studies. As a result of the meta-analysis, it was observed that there is a greater chance of anemia and low levels of ferritin among food insecure individuals. It is concluded that food insecurity is associated with micronutrient deficiency. Understanding these problems allows the creation of public policies capable of contributing to changes. Protocol registration: This review was registered on the PROSPERO-International Prospective Register of Systematic Reviews database—CRD42021257443.