The vitamin has been reified. A chemical intangible originally defined as a unit of nutritive value, it was long ago reified into a pill. Now it is a pill; no one except a few precise scientists define it as anything else. Once the vitamin became a pill, it became real according to the precepts of American Cartesianism: I swallow it, therefore it is.
Great athletes train their minds as well as their bodies. There are various mental conditioning techniques many use when preparing for an event. Perhaps the best known technique is visualization, creating a mental image not only of the desired result (the gold medal, a new world record, a hole-in-one), but also of every move that will be taken en route to the ultimate goal.