Beriberi is caused by the deficiency of

Thiamine is needed for carbohydrate metabolism and nerve function; its deficiency leads to beriberi with nerve damage and weakness. Riboflavin deficiency causes cracked lips and skin lesions, niacin deficiency causes pellagra, and ascorbic acid deficiency causes scurvy with bleeding gums. Polished rice lacks thiamine. Whole grains, pulses and unpolished rice are good dietary sources of thiamine.