@bigboxes Your concern is much appreciated but the D3 and A1c were meant to be read as separate and unrelated events. My apologies.
I keep a close eye on my D3 levels, but for me, it's quite essential that I at least keep its level in the normal range. For whatever reason, that requires 5k IU. Currently, I'm experimenting with 10k and it seems to work even better, but if my next blood test shows I'm beyond the normal range, of course I'll cut back.
But I should add that since I haven't been tested yet, I only take that dose 4 or 5 times per week and skip about 2 days.
I'm quite certain that you are incorrect about the kidney damage, which as a diabetic, is something I AM concerned about. But admittedly, either 5k or 10k might be excessive for some people. In those cases, I can definitely seeing D3 have some level of toxicity.