According to the great majority of health experts, if you are eating a balanced diet, you donâ€™t need to take vitamin or mineral supplement. Most studies show that the micro nutrient status in athletesâ€™ blood is the same as that of non-athletes. Additionally, taking vitamin supplements has not shown any increase in athletic performance. Extra vitamins and minerals a runner might require they get from the extra food they consume to make up for the calories expended during running.
Iron is the one exception. Runners most susceptible to iron deficiency are woman who run long distances and vegetarians. If you feel tired and have been sleeping fine and not on a calorie restricted diet you might be suffering from an iron deficiency.
As far as taking a daily multi-vitamin / multi-mineral, there are differing opinions. Sports nutritionist and runner, Matt Fitzgerald, advises taking them to fill any micro nutrient gaps left in a runners diet. The general consensus seems to be that taking a multi-vitamin / multi-mineral wonâ€™t hurt but if you eat a balanced diet they arenâ€™t necessary.