Let’s assume you decided you want to enrich your daily food intake with vitamins, minerals and other supplements. The basic question is: What do you need to supplement? And the answer is simple yet unsolvable: It depends on what you eat.
Approach 1) The Scientist:
The FDA provided pdf chart about vitamins and minerals does not contribute figuring out what is missing. One would simply not go through all the things one by one someone ate at a given day to figure out what needs to be supplemented.
Approach 2) The Doctor:
A blood test at the doctors for vitamin deficiency - this would measure most commonly vitamin B12, folate (B9) and vitamin D as well as number of blood cells. Not a lot. You can even do these tests at home with a finger prick blood test. The easy way here would be: Let’s eat everything this test tests for:
Companies like Ritual make a daily multivitamin product that seems to provide all these needed vitamins apart from Iron for whatever reason. Well you got me there. I’ll just go with a “combine it all” multivitamin capsule and an extra one for iron. It's also beautiful designed by their in-house industrial design team. Big plus for me! The end.
Ideally I’d want a blood analysis service to get me a unique mix for my own demands. Until that exists, I’ll just take it all!