Do supplements work?

Maybe. Maybe not.: There are thousands of supplements advertised to do all sorts of magical remedies. Very few supplements have real research studies to show benefits (but manufacturers make claims, based on theories, animal tests, testimonials, chemical similarities, etc... but not based on real research because real research is hard to do and is expensive to do).

Consumer beware: The human diet is one of personal choice & some may follow one that is deficient in one or more agents that can be unhealthy.Some people have conditions where they do not absorb agents in proper quantity for good health. In these people specific supplements, commonly iron & others, are necessary. Since the supplement industry are exempt from most FDA review, they often make unproven claims-beware.

Supplements: whether it be a supplement or a medication I think there has to be a combination of actual efficacy and scientific studies that support that advocacy. the research may be expensive however sometimes the more expensive the research the more likely the bias