I'm not normally a particularly smelly-pit person and can normally get away without frequent showers.
MrsC is a great believer in supplements when getting older and pushed me to start taking older-middle-age-man vit pills. They seem to be mostly various Vit Bs and Iron.
Almost immediately I turned into MrWhiffy. Whiffy, not Whippy, ain't no icecream around here.
I put the blame on the Vit B.
When in my late teens, I took Vit B complex (because the kayaking coach said so). I stank like fish smeared with marmite. Yes, that bad.
Makes me wonder. Googling suggests that it isn't normal to become stinky when just taking recommended daily dose of Vit B.