Taking 1000mg of nicotinamide presents some risks. I use to take that amount because it relaxes me but it can down regulate sirtuins and screw up your body’s methylation.
Risks and Benefits of Nicotinamide (NAM), a NAD+ Booster
https://www.youtube.com/watch?v=WMWG_W7vGI0
That is why I take a tenth or so of that amount.