In the history of the Nobel Prize, a total of 4 people have won the prize more than once. Linus Pauling is one of those four people. He won the award in Chemistry in 1954, and then again for Peace in 1962. This makes him one of only two people to have won the award in two unrelated fields (Marie Curie being the other). He's also the only person not to have shared his prizes - these prizes were not shared with other scientists (as with the discovery of the structure of DNA, credited to Watson & Crick) or humanitarians.
Pauling's work is credited with having helped found both the fields of quantum chemistry (think about our understanding of the atom, and how that shapes our comprehension of how chemistry functions - for instance, that bonds are about the sharing or exchange of electrons) and molecular biology, or the application of chemistry to the biological sciences and the exploration of biology on the molecular level - including his own search for the structure of DNA. In fact, it was Pauling who discovered the secondary structure of proteins - alpha helices and beta pleated sheets.
Pauling's genius in the fields of chemistry and biochemistry in the beginning of his career makes his approach to dietary supplements, starting with vitamin C, even more surprising. In this article from The Atlantic, Dr. Paul Offit discussed Pauling's views on vitamins, minerals, and other supplements. The problem, it turns out, isn't that there aren't any studies examining the impact of these supplements. No - given Pauling's faith in them, multiple studies were done - the support for the claims being made simply didn't exist. No matter how much Linus Pauling wanted extra-dietary vitamins to be panaceas, the evidence from studies repeatedly demonstrated that not only were these supplements not helpful, some can actually be harmful.
The distinction between extra-dietary supplements and what is consumed in food is apparently important. The problems seen from consuming supplements as pills, tablets, or other dosage forms can be avoided if the nutrients instead come from dietary sources. In other words, instead of taking an iron supplement, consuming red meat, green vegetables, and nuts is safer.
All of this just demonstrates that it is important to rely on repeatable, measurable evidence rather than our gut instincts when exploring science. Even geniuses can be lead astray.