The kidney pain that was so severe, I nearly called for an ambulance, followed the day after stopping NR because of the new benchmark of extremity pain. The extremity pain is undoubtedly NR or N+R - I'd experienced this when just on NR as have others.
There is also a dizziness I've experienced when first taking NR which I knew to be the same dizziness frequently experienced 15-20 years prior when my blood-glucose was undoubtedly very high from an extremely sugar diet. I have no doubt that NR and possibly N+R are responsible for the extremity pain (incidentally my feet still felt 'bruised' even now ): it is way too strongly correlated. The uncertainty resided as to whether it was responsible for triggering kidney damage of which I've never experienced the like of.
The possibility that these two events are unrelated seems rather unlikely - it is a question of whether it was direct or indirect (such as stirring up kidney stones, say).
There can be a tendency to be bias against the obvious, because it is the smarter thing to do as we know people leap to connections; however, we can overcompensate too. My health has been excellent for years save histamine problems earlier this year exacerbated, but not caused by NR. I have had great benefits from NR and N+R too, in fact I felt incredible just a couple of days prior.
We have evidence of ribose increasing glycated haemoglobin and NAM inducing glucose intolerance:
https://www.ncbi.nlm...mentation sirt1
In addition:
https://www.ncbi.nlm...pubmed/22559853
In hyperglycemia, the kidneys may play an exacerbating role by reabsorbing excess glucose, ultimately contributing to chronic hyperglycemia, which in turn contributes to chronic glycemic burden and the risk of microvascular consequences.
My diet had been poor recently which I suspect meant elevated levels of blood glucose were pushed higher, which is why perhaps others have been ok. Others have been fine. I'm not interested in banging on about this, I may well be an outlier, but I'd say it is extremely unlikely the problems I've experienced have not been NR, N+R related.