Iodine deficiency isn't as common as it once was; we have other sources of it. Italians use coarse salt that isn't iodized. I never had any problems.
I add a VERY small amount of oil to the pasta water, though most people don't. I don't do it to keep it from sticking, unless it's fresh pasta. I do it to keep it from boiling over.
I see you're avoiding confessing that you use a pot that's WAY too small. That is likely why your pasta wants to stick together.