Here's a rough estimate based on ADAH statements:

"No one knows precisely how many white Alabamians fought for the Confederacy, but estimates go as high as 100,000."

"Between 90,000 and 100,000 white men from Alabama served in the CSA army."

"One-fourth of the one million Southern men who fought in the Confederate army died of wounds or disease."

Extrapolating, that would be 22,500 - 25,000 Alabama soldiers who died of wounds or disease.

But consider that last statement in quotes. Does that include those killed in action? The context of the statement is in regard to Confederate hospitals. Also, don't forget that quite a few Alabamians, particularly from the Mobile Bay area, served in the Navy and Marines.