Well, hey everyone, Dr. David Perlmutter here. Interesting question. What are the three essential supplements that we should be taking during the winter? Too bad you narrowed it down to three, and I'm going to say probably four is what I'm going to come up with. First, vitamin D, of course. Getting less light means less ability of your body to manufacture vitamin D. We know that it's critically important for health to have adequate amounts of vitamin D on board. I've blogged about this aggressively in the past, so go to the website and read about why. Next, if there's a sleep issue, and there may very well be, then melatonin is a good choice. I think that when there's less daylight for you who are living at far northern latitudes or far southern latitudes for that matter, the shortened day might be an issue as it relates to developing things like seasonal affective disorder. So might consider melatonin to keep that chronological clock where it needs to be. I think taking DHA, a very important omega-3, is important as well. And I would also think that in the wintertime, sometimes people are a little less active. So is there a mimetic of physical activity, a mimetic of exercise? Probably not, at least in terms of a supplement, but you might consider taking quercetin, 500 milligrams a day, to stimulate AMP kinase. Hope that's helpful.