Happily, buckwheat has significant amounts of Vttamin B1. Soba noodles add thiamine to the Japanese diet, filling in the gap left by white rice, which is deficient in the vitamin. A delicious bowl of soba noodles now and then = no beriberi.
Buckwheat's not the only food which has thiamine in it, of course, but its' so easy to add a cup of buckwheat flour when, say, making pancankes from ready-made mix, as I did this morning. I'm one of those people who occasionally gets leg cramps at night, and some of the B vitamins, including B1, can hrlp prevent neuromuscular misfires which can lead to tingling and/or cramping in the feet or legs.