The negative health effects of inadequate magnesium intake are well established, but the extent of the problem of deficiency warrants further exploration. This review explores the dietary factors, such as changes in agricultural practices and dietary patterns, that affect magnesium consumption over time and examines the current adequacy of magnesium intake among adults in the United States. Large, cross-sectional, population-based data sets confirm over half the adult population in the United States does not consume adequate amounts of magnesium, although recent population-based studies show a steady and consistent recovery in magnesium consumption over the last several decades. Because there is no simple, rapid, accurate test to determine whole-body magnesium status, continued monitoring of magnesium consumption is essential to determine whether the trend of increasing magnesium consumption will continue. In the meantime, since the clinical consequences of inadequate magnesium status are well established, there are few reasons not to encourage increased magnesium intake in adults, especially since magnesium is found in healthy foods that should be consumed more often and there are no reported cases of hypermagnesemia from food alone.