What is the cause of beriberi disease?

a) Deficiency of Vitamin B1

b) Deficiency of Vitamin B6

c) Deficiency of Vitamin B9

d) Deficiency of Vitamin B12

The disease beriberi is caused by the lack of vitamin B1, It is also known as thiamin deficiency. Beriberi is characterized by impairment of nerves and heart. Its general symptoms are loss of appetite and weakness in the limbs.