Biofortification is the process of increasing the concentrations and/or bioavailability of micronutrients in staple crops and has the potential to mitigate micronutrient deficiencies globally. Efficacy trials have demonstrated benefits of consuming biofortified crops (BFCs); and in this paper, we report on the results of a systematic review of biofortified crops effectiveness in real-world settings. We synthesized the evidence on biofortified crops consumption through four Impact Pathways: (1) purchased directly; (2) in informal settings; (3) in formal settings; or (4) in farmer households, from their own production. Twenty-five studies, covering Impact Pathway 1 (five studies), Impact Pathway 2 (three), Impact Pathway 3 (three), Impact Pathway 4 (21) were included. The review found evidence of an improvement in micronutrient status via Impact Pathway 4 (mainly in terms of vitamin A from orange sweet potato) in controlled interventions that involved the creation of demand, the extension of agriculture and promotion of marketing. In summary, evidence supports that biofortified crops can be part of food systems interventions to reduce micronutrient deficiencies in farmer households; ongoing and future research will help fully inform their potential along the other three Impact Pathways for scaling up.