The deficiency causes night blindness and other manifestations, such as xerophthalmia, which is unable to produce tears, destruction of the cornea (keratomalacia) and blindness” (Sommer). Thiamine, also known as vitamin B1 deficiency, is linked to beriberi, which can cause "weight loss, emotional disturbances, impaired sensory perception, weakness and pain in the extremities, and periods of irregular heartbeat." tissues) is common. It can increase the amount of lactic acid and pyruvic acid in the blood. In advanced cases, the disease can cause high-output heart failure and death”