I do use supplements, and I consider them an extension of my food a part of my diet. I try to find good sources and take them regularly - rather than, as you say, occasionally, so they accrete in my system and my wonderfully adaptive body has them on hand as needed. Some to address specific things, like ashwaganda or adaptogenic mushrooms for cognitive health, others for nutrients that are required, but harder to get enough of through diet, like magnesium. In any case I would say all of the above, food, sleep, exercise, stress management and supplementation are helpful to a balanced life. We live in a world of uncommon stress, it is useful (to me) to have a few extra tools to balance that out.