If combinations of cereals and legumes are used, protein deficiency is extremely unlikely, and numerous studies have proven not only the adequacy, but also the superiority of plant proteins over those of animal origin.Indeed, the reverse is true in that it is difficult not to exceed recommended protein allowances on a varied vegetarian diet.
In the United States many studies of vegetarians use cohorts of followers of the Seventh-day Adventist Church, a Christian denomination that promotes, among other things, a wholesome and healthy lifestyle.
Many Seventh-Day Adventists also avoid alcohol and smoking.
Moreover, pregnant or lactating women and infants and growing children also need specific dietary consideration.
However, if due consideration to these points is given, a total plant-based diet can supply all our dietary needs.
Regarding the other nutrients listed, all these nutrient requirements can be met by plant foods, except for vitamin B12, but this can be supplied through fortified soybean milk, nutritional yeast grown on a B12 medium, or through supplementation.