I got +100% health from pickups due to the apothecary upgrade and +100% from the priest skill. Together it should triple the strength of health pickups, instead it makes them 10 times stronger (got 750 hp from a cheese). I guess the boni aren't added together, they are multiplicated instead?
Edit: an apple gave me 150 hp. Which would be 15 times stronger iirc. I have no items which modify pickups.
Edit2: Next round, it went back to normal. 30 hp per apple. strange