Can I take nitratine that's in a supplement d pol and still use viagra (sildenafil) or cialis?

Best to avoid D-pol. Nitratine (sodium nitrate) is marketed as a supplement to increase blood flow (via its metabolite, nitric oxide) during exercise, allowing for longer workouts & faster muscle development. However, to my knowledge, there's no medical proof that it works. If it does work through nitric oxide, then PDE5 inhibitors like Viagra (sildenafil) could bottom out your BP, theoretically, which is not safe. Best not to use.