Why did rich Chinese eat peeled rice in the 19th century suffer from beriberi disease?

Refined rice is only a white grain, it is devoid of coarse skin. But it is in this shell that rather important substances are contained. The grain of rice itself contains only starch. And in the shell of the grain there is a B vitamin – thiamine. Lack of it leads to problems with the nervous system, paralysis. Since wealthy Chinese for a long time ate only tastier, peeled rice, very soon there was very little thiamine in their bodies. Beriberi’s disease, or severe vitamin B1 deficiency, developed.