Elder John A. Widtsoe

The phrase "in the season thereof," referring to fruits and vegetables, has raised much speculation. It indicates simply the superior value of fresh foods as demonstrated by modern science, but does not necessarily prohibit the use of fruits or vegetables out of season if preserved by proper methods.
The Word of Wisdom is not a system of vegetarianism. Clearly, meat is permitted. Naturally, that includes animal products, ... such as eggs, milk, and cheese.

(Elder John A. Widstoe, Evidences and Reconciliations, Vol. 3:156-157)

Section 89

Doctrine & Covenants