Can a regular vegan stay healthier with vitamin supplements?

No: If you don't have a deficiency, supplements offer no benefit and according to some recent studies may actually cause harm. See september 2012 issue of consumer reports article on the dangers of taking vitamin supplements. The only way to know if you have a deficiency is to be tested for it. See your doctor to discuss test options. Vegans are at increased risk of a vitamin B12 deficiency.

Absolutely: The vegan diet offers a moral high ground and possibly some health benefits, though they are elusive when we control for the fact that vegetarians tend to have other healthy lifestyle habits. If you do not supplement with vitamins -- famously B12 -- and some minerals such as iron and calcium, your health is in serious danger from it. Find a vegan-friendly physicain in your community.