They are all needed. Every vitamin/mineral in the body is a co-factor for different metabolic processes. The B-vitamins are involved in energy metabolism, vitamin E/C are antioxidant and involved in collagen synthesis, minerals like magnesium are important for electrolyte balance and hormone production etc.
Athletes have greater requirements of vitamins then their sedimentary counterparts. They don't require just more of a specific vitamin, they require more of all vitamins. A good quality multivitamin supplement is a great supplement to use to ensure your body is getting all the vitamins and minerals it needs each day for optimal health.
The biggest thing to look for when shopping for a multivitamin is what form the minerals are in. Most supplement companies uses mineral oxides in their multi vitamin products because they are cheap. The problem with that is they only have a 2-4% absorption rate. Take magnesium or zinc as an example. Look at the supplement facts and you will see that the forms of 'magnesium oxide and zinc oxide' listed.
What you want are amino acid chelates. You want to see 'magnesium amino acid chelate and zinc amino acid chelate'.
Check ruthless 3d from n2bm.com. It is very affordable and only contains amino acid chelated minerals. It also has higher dosages of B vitamins, vitamin C and vitamin E.