I think its somewhat of a mistake, particularly if we are using the organic method, to think solely in terms of percentages of N-P-K. Rather our thinking should be: what makes a significant contribution?
Bananas are a source of potassium and phosphorus. You can throw the peel in the hole, or better yet, throw in the whole thing - eggshells too. One thing most have failed to comprehend catch on to is that tomato plants love fresh garbage.
Don't get me wrong, composting is good too. I am an avid composter, but you don't have to compost them. Leave the TUMS alone though.
