But Goetz implies that the vitamins may have benefits in the right regime:
This is not how vitamins work. Vitamin A is toxic in doses over 15,000 IU/day, and vitamin E is toxic in doses over 400 IU/day (Miller et al. 2004, Meta-Analysis: High-Dosage Vitamin E Supplementation May Increase All-Cause Mortality; Berson et al. 1993, Randomized trial of vitamin A and vitamin E supplementation for retinitis pigmentosa.). The RDA for vitamin A is 2500 IU/day for adults. Good dosage levels for vitamin A appear to be under 10,000 IU/day, and for E, less than 300 IU/day. (Sadly, studies rarely discriminate in their conclusions between dosage levels for men and women. Doing so would give more useful results, but make it harder to reach the coveted P < .05 or P < .01.)
...Vitamins, like any medicine, have an inverted-J-shaped response curve. If you graph their health effects, with dosage on the horizontal access, and some measure of their effects—say, change to average lifespan—on the vertical axis, you would get an upside-down J. (If you graph the death rate on the vertical axis, as in this study, you would get a rightside-up J.) That is, taking a moderate amount has some good effect; taking a huge a mount has a large bad effect.
It would be a strange usage of ‘good’ if all Goetz meant by it was ‘increases fatalities by too small an amount to easily detect’ rather than ‘increases some desirable outcome’.
But Goetz implies that the vitamins may have benefits in the right regime:
It would be a strange usage of ‘good’ if all Goetz meant by it was ‘increases fatalities by too small an amount to easily detect’ rather than ‘increases some desirable outcome’.