Pronunciation: (meg'u-vī"tu-min; Brit. also meg'u-vit"u-min), [key]
of, pertaining to, or using very large amounts of vitamins: megavitamin therapy. Cf. orthomolecular.
megavitamins, doses of vitamins much larger than the recommended dietary allowances.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.