What vitamins should i take before start my marathon training?

Any multiple: Vitamin! i personally use extra vitamin c.

Review nutrition: You should review and set up some sort of nutrition plan for your training and running a marathon. Supplements are very important, those for helping the bones, muscles, circulation, immune system, etc. You may want to contact a nutritionist in your area. Eating well is the first priority, then supplement

Usual: Whatever you usually take. Some people like to add C and Zinc, but that is a personal preference. As long as you train properly and eat nutritiously you will have all you need. You need to be sure to get enough protein, as you are challenging your muscles and need to rebuild. See some of the excellent training plans for details. Runnersworld.com is a good place to start. Good Luck.

Fruits and Veggies: There's no strong scientific evidence that taking supplements improves either health or athletic. Take Multivitamins for placebo effect. Best of luck.