Fatigue after 40 often gets blamed on stress, sleep, hormones, parenting, work, or “just getting older.” Those can all matter. But two common, fixable problems often sit underneath the exhaustion: low iron and low vitamin B12. Both nutrients help the body make healthy red blood cells and move oxygen. B12 also supports nerve function and DNA production. When either one runs low, the result can feel like more than normal tiredness. It can feel like walking through the day with