Comment by ksaj

It is apparently sold as an anti-aging supplement, which exacerbates the issue since those in the anti-aging interest group are also in the "old enough to be concerned about cancers" group.

As well, NR is plant derived, versus the other two types that tend to be animal derived. So I assume vegan vitamins would be a likely product range to use NR as B3. This already occurs with vegan Vitamin D, where D2 is plant-derived, and D3 is generally animal derived.