 The human nutritional requirements varies from ~60 mg·kg−1·d−1 in infancy to ~30 mg·kg−1·d−1 in adults.This requirement is commonly met in a western society with the intake of lysine from meat and vegetable sources well in excess of the recommended requirement.In vegetarian diets, the intake of lysine is less due to the limiting quantity of lysine in cereal crops compared to meat sources.