It would be a good idea to look closely at your supplements and see if there are duplicates of particular vitamins and minerals so you can get a better idea of exactly what you are consuming. Your first post mentioned calcium carbonate and vitamin D so some of your supplements may be duplicating others (or not). 21 supplements a day is quite a lot. A low-dose multi is probably okay for most people but in general, it's a good idea to focus on whole, nutrient rich foods and then supplement where your diet may fall short. For example, I cannot eat dairy so it's a bit more challenging to meet my calcium needs. I calculate my calcium on cronometer.com (free) and if I do not meet the daily need of 900-1200 mg, I take a small amount to supplement which generally amounts to about 300 mg a day at most.
It might be a good idea to run this by your provider or meet with a Registered Dietician to see if you are meeting your nutritional needs and/or if your supplements might be too much of a "good thing".