Ross Elliott, who played the director, said of this episode: "I chewed the inside of my mouth out to keep from laughing out loud. Lucy would do new stuff that wasn't rehearsed, like an extra-funny face. Then, at one point, she became 'drunk' and started making eyes at me, flirting, and I almost broke up again". (From: "The I Love Lucy Book" by Bart Andrews).
The original script had an end scene where Lucy has a bad hangover from too much Vita. Ethel goes to the store and brings Lucy home some Vita to help spoon her way back to health! This scene was cut for time.
When Lucy's "test commercial" from inside the TV set originally was filmed, she imitated the Phillp Morris bellboy and said several Phillip Morris references. These were cut from syndication. The DVD restores the original footage.
The cast and crew looked high and low to find the perfect substance to act as Vitameatavegamin. They wanted it to be something Lucy could drink a lot of and something that had the perfect viscous quality. They finally settled on apple pectin, and Lucy said it was very sickening to drink that much of the sweet liquid.
Desi said that it was virtually impossible to keep from laughing during the part where Lucy has to prove to Ricky that she's fit to do the commercial. Desi had to bite the inside of his cheeks to keep from laughing out loud, and you can see in the episode how he's struggling not to lose it. During other parts of the commercial, Desi clearly was watching from the audience, and you can hear his very distinct laugh.
Besides lines from the actual commercial part (such as "spoon your way to health"), the two slogans for Vitameatavegamin were "Join the parade. Buy Vitameatavegamin today." and "Vitameatavegamin for health."