Why do individuals with a thiamine-deficient diet have relatively high lev?

Truncated question: Thiamine-deficient diets in real life are seen only in famine / starvation and in people who are intoxicated for weeks at a time. They get brain and nerve damage and the heart eventually fails. I'm sorry the question was truncated even if it was homework; if someone's diagnosed you with thiamine deficiency on a normal diet, consider a phone call to your district attorney. Good luck.