For the average fat ass american who eats his 5000 calories w/o having any physical activity, a multivitamin may be useless
But we are, I mean here, on EF, people who train hard, push much iron and/or spend much time doing cardio
So we have needs, in vitamins and minerals, that other people don't have
=> a multi is actually one of the most effectibe supplement and you should take one
If possible not a Centrum which is very poorly bioavailable
And you'd better take low dosages 2 or 3 times a day rather than huge dosages once a day