A very large dose of a vitamin or drug.
- ‘Although the study results suggest that vitamin C may have a protective effect, it does not present conclusive evidence, nor do the researchers recommend megadoses of vitamin C to reduce heart disease risk.’
- ‘But a 2004 report suggests that taking megadoses of vitamin E may actually do more harm than good.’
- ‘Although there is no evidence that they will do you any harm in the usual doses, megadoses have been reported to have side effects and actually decrease optimum physical performance.’
- ‘Take only the recommended daily allowance of vitamins and minerals and avoid megadoses.’
- ‘He treated himself with multivitamins and minerals, plus megadoses of vitamin C - and I do mean mega; at one stage he was taking over 100 grams per day.’