I am 55 and I have slowed down, but now that I am getting into a real "trainingprogram" I am feeling better than I have in twenty years!!
I take 1000 mg of vit C, 400 IU of vit E & a multi vit.
I got back into riding about three years ago. I now ride only on the road and I put in about 2000 to 2500 miles a year. I ride almost daily now.