It's an article on melatonin. Vitamin D and magnesium are discussed elsewhere ( http://www.gwern.net/Nootropics#vitamin-d http://www.gwern.net/Nootropics#vitami

It's an article on melatonin. Vitamin D and magnesium are discussed elsewhere ( http://www.gwern.net/Nootropics#vitamin-d http://www.gwern.net/Nootropics#vitamin-d , http://www.gwern.net/Nootropics#magnesium http://www.gwern.net/Nootropics#magnesium ), but gwern's focus isn't on old people because he's not an old person, so it's harder to self-experiment on them.