Some people choose to replace bed slats with a sheet of plywood to provide uniform support for the mattress. The plywood should be at least three-fourths of an inch thick. \
However, sleeping on a plywood board is not the same as sleeping on slats. There is a hard surface beneath the mattress, or the mattress and box spring if you have both, with means the mattress will get compressed by your body weight over time. \
The mattress also won't breathe as well without slats. Moisture from your body could collect beneath it and create mold, which is a problem you don't want. \