Looks like Thiamine deficiency is a very common occurence, and very scary. It seems to be easily undiagnosed by the medical cabal. The article by Marrs and Lonsdale is very interesting.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8533683/
About 10% of thiamin is also lost due to freezing of foods.
Great article. Thanks for posting!