Carrot juice

 was a beverage made from carrots enjoyed by Melanie Bush for its healthful properties. She tried to get the Sixth Doctor to regularly consume it to improve his health. She claimed that its main ingredient, carrots, were rich in Vitamin A. The Doctor did not particularly enjoy it and claimed it was having an adverse effect upon him. He said, almost certainly untruthfully, that it was making his ears grow and inducing a limited form of colour blindness. (TV: Terror of the Vervoids, The Ultimate Foe)