Everybody body is different, you see my Avatar that's me, I know what I'm doing, Bodybuilding, Power Lifting is a Science, diet is a Science, Supplements is a Science, everything is from trail and error, I do what works for my body, what's good for me is not good for you, what's good for you is not good for me.
Physiology, Biology, Dietary I study. My circle is of Professional and Amateur Bodybuilders, Pro Power Lifters, Sports Science and Dietitians, Strong Man and Physique Competitor's. I know about Food, Diets, Supplements, Anabolics.
But Good Lookin for the Concern though, My results and study speak for itself, that's the beauty of bodybuilding and strength training, you is science project.
Now let's get to the Science
Vitamin D - I'm a Black Man, Sun gives me life, my skin absorb the rays. Well we still having winter like weather and during these times due to shorter days and miserable weather we don't get alot of sunlight, and that's why you see lot of black people that go through depression around this time because of that. Vitamin D helps against that until the spring and summer returns
Glutamine and ZMA gives my body great sleep when I take it, not only that but it increase my GH when I sleep, I wake up the next morning feeling great, more energy and in a anabolic state, my body responds great.
This is what people need to understand, you go by what your body responds to, everybody thinks they have the answer to what to take, what works and don't works. Your body have the answers because all of us are different