Mg is a great muscle relaxer, and good for headaches. It never did much for my sleep (insomnia) but worked for many colleagues.
Funny, I dont remember mentioning that I take my multi in 2 doses, but yes, halfing and staggering you multivitamins is great, just not convenient. You simply get more out of it. Metabolisms works more efficiently that way, simulates our ancestors grazing as they traveled.
I take 2 "doses" of my supplements. Half in the morning an hour or so after breakfast, and second dose an hour or so after lunch.
Take what you need.
My current regimen is:
MVI: I am in the cutting stage and eating less calories than I need, and thus not providing adequate micronutrients.
CoQ10: other than being one of my favorite supplements, it has shown to be effecitve in prevention of HD, especially if in the family history. Which is my case. Vital in the TCA cycle and making ATP.
FIsh oil: reduce inflammation from bad diet days, and for the above reasons related to cardiac issues.
Milk thistle: I was exposed to TB during my clinical rotation, it is latent (not alive or contagious) but I want to kill it completely, so I take INH, which can cause liver damage. Hence the milk thistle.
Ginseng: Increase daily energy levels, but not exercise performance. And also kick up the notch in the bedroom; definitively
Vit D: a cohort study showing the current world diet is deficient in vit d, and the originally accepted plasma levels were not adequate. Immune and hormonal enhancement top the list. Although the RDA is 400 UI, that is based on old research. Go with ~2000 per day. Take on days you dont get sun exposure (up north, office jobs etc).
Make sure to take only what you think you may need, and dont take those mega dose anythings. They are more than just a waste, they can cause a myriad of issues, including increased growth of cancerous tumors, especially the methyl transfer varieties. Many time excessive doses causes symptoms similar to a deficiency of the same vitamin/mineral.