Final answer:
BeriBeri is historically the classic deficiency state of vitamin B₁. It is a condition caused by a lack of thiamine (vitamin B₁) in the diet and is characterized by symptoms such as polyneuritis, edema, cardiovascular changes, and weakness.
Step-by-step explanation:
BeriBeri is historically the classic deficiency state of vitamin B₁. BeriBeri is a condition caused by a lack of thiamine (vitamin B₁) in the diet, and it is characterized by symptoms such as polyneuritis, edema, cardiovascular changes, and weakness.