Sunspots, I spent more time reading this morning. It's a complex subject. I'd need to spend a lot more time reading about this to provide an informed opinion.
I do understand your suspiciousness about the promotion of any nutritional supplement. I personally do not add any nutritional supplement until I've done a lot of reading on it. (Two people have written extensively on balancing intake of A, D3, K2 and magnesium and both reference their work: Chris Masterjohn, Ph.D., and Kate Rheaume-Bleue, N.D., B.Sc.)
However, I have read enough now on the benefits of getting the intake and balance right for vitamins A, D3, K2, and magnesium to reduce calcification of soft tissues and to improve teeth and bone health.
I have made changes to my diet and my nutritional supplement regimen to balance those nutrients due to the two diabetic complications affecting me personally: chest pains that began after I recently resumed supplementing with calcium, and muscle weakness (a type of neuropathy). Eye, kidneys, and liver are fine.
I'm now taking cod liver oil (Vitamin A), Vitamin D, MK-7 (K2 sourced from natto), and magnesium (in addition to taking an organic, whole food, vitamin and mineral supplement, and eye protector formulation, fish or krill oil, and CoQ10).
For now I have stopped supplementing with calcium but am continuing to eat calcium rich foods. In addition, I'm continuing to eat eggs, and am now eating butter from grass fed (not grain fed) cows and eating Gouda cheese, all natural sources of K2. Chest pains have remitted.
My husband went through this twice. Very painful. The first kidney stone was removed with Shock Wave Lithotripsy, the second was more problematic but he was eventually able to pass it.
I asked him what he did to resolve the problem. He said he didn't want to do the diet. Instead he increased his daily water intake by 1 liter, and no longer has the problem.
It's good that they're going to remove the stone, and, I assume, test it to determine what the stone is made of so you'll know exactly which foods you need to restrict.
You'll read a lot about increasing water intake and drinking fresh lemon juice daily. If you go that route, protect your teeth enamel from the lemon juice by drinking it with a straw.
Good luck. Let us know what you learn and works for you.