There are substantial pragmatic difficulties in assessing the impact of nutrition in osteoporosis. The focus of this chapter is the relationship between nutrition in the development and progression of osteoporosis. There is no ideal way to assess the impact of diet on bone health (or other outcomes). The assessment of causation should therefore be queried using different kinds of studies such as randomized controlled trials, cohort studies, and experimental animal studies as a means of triangulation so that strengths of a given design are weighed to support or refute a scientific hypothesis. We will briefly review the association between specific micronutrients and bone health and then review macronutrients and dietary patterns. Central to the review of specific nutrients are dietary reference intakes as established by the Institute of Medicine and Food and Nutrition Board.