The exercise is to decide whether the question accepts the proposed suggestion as a correct answer. If yes, write "True", otherwise write "False". Question: how many classes of vitamins Suggestion: Until the mid-1930s, when the first commercial yeast-extract vitamin B complex and semi-synthetic vitamin C supplement tablets were sold, vitamins were obtained solely through food intake, and changes in diet (which, for example, could occur during a particular growing season) usually greatly altered the types and amounts of vitamins ingested.
A:
False