Thiamine Deficiency Woe is a medical condition more commonly known as Beriberi (8 letters). It is caused by a lack of thiamine, also known as vitamin B1, in the body. Symptoms of Beriberi include fatigue, muscle weakness, and heart problems. It is most common in areas where white rice is a staple food, as it is stripped of its thiamine during processing. Treatment for Beriberi includes thiamine supplementation and dietary changes.