Capsule

Megavitamins are Dr. Mario's prescription of choice, seen in the Dr. Mario series. Invented by Dr. Mario himself, Megavitamins are an effective weapon against both Viruses and the flu.

They come in six different color combinations of red, blue, or yellow (Red+red, blue+blue, yellow+yellow, red+blue, yellow+blue, red+yellow, or in the Game Boy version Black+black, grey+grey, white+white, black+grey black+white and white+grey). Dr. Mario uses the megavitamins to destroy Viruses, in the game Dr. Mario. In Japanese, Megavitamins are simply called カプセル(Kapuseru); Capsules.

In Super Smash Bros. Melee and Super Smash Bros. for Nintendo 3DS / Wii U, Dr. Mario's neutral special is Megavitamins, in which Dr. Mario tosses a Megavitamin at opponents. They act the same as Mario's Fireball move, except that the Megavitamins are more powerful. They also bounce in a different path, and make a different noise when it hits. There's also a trophy of Dr. Mario shooting Megavitamins and one of the vitamins themselves. Kirby is also able to use the Megavitamins if he copies Dr. Mario, although the sound that plays when the Megavitamin hits an opponent is different. Like in the Dr. Mario games, the Megavitamins are randomly generated with different color combinations, though this has no effect on the attack itself. Super Smash Bros. for Nintendo 3DS / Wii U also gives this move two customizable variants, which are similar in effect to Mario's Fireball customs. The first is Fast Capsule, which sends out a fast-moving but weaker Megavitamin that travels directly forward, and the second is Mega Capsule, which sends out a slow-moving giant Megavitamin that does not travel as far but deals multiple hits of damage.

In Super Smash Bros. Brawl, a Megavitamin appears as a Sticker, which boosts the attack of the equipped character by five points.

In Dr. Mario 64, Megavitamins also seem to have a transforming property; when Dr. Mario or Wario eats them, they transform into Metal Mario and Vampire Wario, respectively.

Trivia

 * There is a planet in Good Egg Galaxy in the game Super Mario Galaxy that resembles a Megavitamin.
 * One of the things thrown at Vanessa in WarioWare: Touched! is a red+blue Megavitamin.