Iron, B12, Omega 3, creatine (might improve cognition, apparently. Feel free to source in comments)
In the Four Hour Body, Tim Ferriss asserts that more Iron is correlated with higher mortality and suggest that you should rather do blood donations to reduce the amount of iron then to take supplements for it.
Have a sugary multivitamin so you actually take all of your vitamins
This ignores the question of whether taking a multivatamin provides benefits and most studies of multivitamins don't find benefits.
I think it's highly questionable to override your bodies sense of what vitamins it wants with sugar in the case of multivitamins because your body might have a good reason to get you to avoid a product that's unhealthy for you.
Tons of handy stuff here, thanks!
I love the sound of Cold Turkey. I use Freedom for my computer, and I use it less than I otherwise would because of this anxious feeling, almost certainly exaggerated but still with a basis in reality, that whenever I start a full block it is a Really Big Deal and I might accidentally screw myself over - for example, if I suddenly remember I have to do something else. (Say, I'm looking for houses and it turns out I actually need to go look something up). But Cold Turkey, I'd just block stuff a lot more freely without the anxiety - I'll know if I really need something I can unlock it. All while having the calm that comes from Twitter not being immediately accessible.
I also find the Freedom interface really terrible and that trivial inconvenience can keep me from starting blocks.
How often would you say you spend time-you-don't-endorse after unlocking something with the N random characters? Is it pretty effective at keeping you in line?
[Read bolded words to skim]
Below are a bunch of tips, systems, and devices for improving productivity. I don't mean to claim I know a lot about productivity—I think there is likely a lot of useful advice I am missing. If you are new to thinking about productivity, a lot of this stuff might be useful, though it is probably better to instead aim for the mindset that can generate these tips and habits for yourself. For this, I recommend attending a Center for Applied Rationality workshop, reading the CFAR handbook, checking out Neel Nanda's blog, and/or reading Rationality: A to Z (podcast form here).
My recommendations are in very rough order of how much I recommend them, based on how excited I am/would expect someone else to be to know about the tip (my top recommendation being Things 3 + Apple Watch). Though I didn't try that hard to order things in this way.