Question: what is the difference between m and d in shoe width?
Answer: In American shoe sizing, letter indicates width. C is narrow, D is standard (or medium, hence the accompanying "M") and E, EE (or 2E), AND EEE (or 3E) are the extra wide sizes. If most off-the-shelf shoes in size 44.5 fit you, go with a corresponding US size in D(M).