Vitamins & Minerals

This exact no-flush niacin ingredient failed its own placebo-controlled trial, and a 25,673-patient trial of real niacin found no heart-attack benefit either.

NIH's 35,533-man SELECT trial tested vitamin E for cancer prevention and found a 17% higher prostate cancer risk instead of the protection it aimed to show.

A standard 65 mg iron tablet already exceeds the NIH's adult limit, and federal law requires an overdose warning on every bottle. Here's what the evidence shows.

A 312-person trial found elderberry cut cold duration by two days, but this popular immune supplement also packs a vitamin D3 dose over the adult safety limit.

A 388,229-person NIH cohort study found high-dose supplemental calcium raised heart-disease death risk in men by 20% — but not from food, and not in women.

A 1,242-patient meta-analysis found real benefit for diabetic nerve pain at 600 mg a day — but this product's own label tops out at 480 mg. See the evidence.

Zinc shortens cold duration by 1.5 days if taken within 24 hours, but chronic daily doses near the 40 mg NIH upper limit trigger copper depletion.

Every OTC potassium tablet caps at 99 mg because of a 1975 FDA rule, not nutrition science. Here's what the NIH says adults need, and who's really at risk.

NIH sets vitamin B6's upper limit at 100 mg a day; the EU sets it at 12 mg. This capsule delivers 250 mg daily. Here's what the nerve-damage evidence actually shows.

NIH caps adult vitamin D at 4,000 IU (100 mcg) a day, yet a popular 5,000 IU softgel sells at 625% of the Daily Value. Here's what the trial evidence actually shows.