Durk Pearson & Sandy Shaw had a best seller with their book Life Extension, which was an interesting read: basically biochemistry, plenty of theory and a touch of voodoo for example, DMSO. It is supposed to good at clearing up bruises, used topically. It also imparts a garlicky taste in the mouth, making double-blind studies nearly impossible. (It is also a great solvent and excellent delivery system for getting things into the bloodstream. Say, for example, DMSO and LSD being sprayed on folk at a Grateful Dead concert. Glad I wasn't driving!)
This was in the 1980's and there was quite the melee going on--Homeopaths, "real" Doctors, acupuncture, and the mega supplement gurus. Pearson and Shaw listed what they were taking and that anyone jumping straight in was a "damn fool," if they didn't build up to similar mega doses without a Doctor's supervision.
People (damned fools) with the mindset "if one is good two are better!" established that some of these things that are good for us can cause cancer when taken in extremely large doses.
In smaller doses there does seem to be some uses for water-soluble vitamins. Example: Niacin, (B-3) Benefits of Niacin and Flushing - Toxins and Capillaries | Life Priority, Inc.
Still, keep in mind that we all don't have the same body chemistry. I think the best thing we can do for ourselves is simply living a healthy lifestyle and practicing.