Vitamin A and E supplements not only provide no health benefits for generally healthy individuals, but they may increase mortality, though the two large studies that support this conclusion included smokers for whom it was already known that beta-carotene supplements can be harmful.
Tilskud af vitamin A og E kan sågar øge dødeligheden hos sunde individer, omend de to store studier, som understøttede denne konklusion, inkluderede rygere for hvem det allerede var kendt at betakaroten-tilskud kan være skadelige.