Polyneuropathy from thiamin deficiency can occur in persons who consume a diet consisting mainly of polished rice with low protein and thiamin content in the setting of excessive physical activity or hypermetabolic states. The authors report here a 17-year-old fisherman who presented with a 3-month history of
symptoms and signs consistent with polyneuropathy. There were also clinical features of thyrotoxicosis which was confirmed by thyroid function test. His dietary intake consisted mainly of polished rice and fish both of which contain a small amount of thiamin. This could not cope with his hypermetabolic condition from thyrotoxicosis resulting in thiamin deficiency with polyneuropathy.

Keywords: Polyneuropathy, Thiamin, Thyrotoxicosis