Individually. Sometimes a few things are combined when a good option is available, but generally multivitamins don't give me what I want in the doses that I want.

Since I tested all of my blood metrics beforehand, it's unlikely the market would have a 'perfect' vitamin for me. Especially since most of what I like to take isn't technically a vitamin.

My diet is currently pretty un-optimized, so although I would prefer to consume a lot of things via diet, it's not guaranteed at all. But the extra bio-availability and such is likely nice

Id be curious what it would look like if you tested your blood now, stopped taking them all, and radically modified your died, what kind of results you would get in a couple weeks.

Daily intake of, tomato juice, kefir, sardines, salmon, spinach, sunflower seeds, pumpkin seeds, pistachio, eggs. You could probably get a whole days worth of food into a snack, a salad, and a soup.

I wish it was easier to do intensive tracking of everything like that, but it's definitely a lot of work. Some supplements I have very clear before+after results, with the only probable cause being the supplement (e.g. vitamin D or magnesium), but a lot of others are hard to test, control for, find biomarkers for, etc.

I do know there are a few people in the area that log literally every substance they eat in terms of grams, and then correlate it with all of their blood metrics, and use that to try to optimize each blood metric for what correlates with the lowest mortality rate. It's interesting, but this stuff is unfortunately a lot of work for average people to attempt. Here's a great example: https://twitter.com/Nearcyan/status/1282042301980835842