J Am Diet Assoc. 1985 May; 85(5): 569-72.

Mineral analyses of vegetarian, health, and conventional foods: magnesium, zinc, copper, and manganese content.

McNeill DA, Ali PS, Song YS.

The amounts of magnesium, zinc, copper, and manganese in 22 health and vegetarian foods and their conventional counterparts were measured. Increased levels of magnesium were associated with the presence of soy in vegetarian and health products. Zinc was low in the vegetarian meat and egg substitutes and in soy milk. Copper tended to be decreased in the vegetarian foods but increased in the health foods relative to levels in the conventional counterparts. Manganese levels were increased in most of the health and vegetarian food items relative to levels in the conventional foods.