[Someone]

"I hope everyone understands that there is NO reliable evidence that any dietary supplements, including vitamins, provide any health benefits whatsoever to healthy people."

I sort of agree with that, but I also know it is kind of a tautology. 'Healthy people' can't become 'healthier people', by definition. Yet, every healthy person can imagine himself, but slightly better: better vision, more willpower, stronger, faster runner, more intelligent, etc.

Because of that, there are no 'Healthiest people'. Even the hypothetical person who wins the decathlon at the Olympics at the age of 40 in the year they won their fifth Nobel will have something to desire (a bald spot? Feeling more tired after exercise than he used to be?). In that sense, nobody is truly healthy.

That is what all the supplement sellers play at.

[spikels]

This is not a tautology. Every "healthy" person will someday die and will often develop cancer or heart disease or have a stroke or have one of thousands of rarer medical conditions. If any supplements actually worked they would prolong life or reduce the occurrence of any of these diseases. All of these out comes can be measured in a properly designed study. So far there is no reliable evidence that supplements help with any of these outcomes.