D.B.
The bulk of the evidence indicates that vitamins and minerals don't work in isolation. They are all interdependent, and function best when taken in a fully comprehensive form. Moreover, that form has to be highly absorbable. That's why you'll hear so many doctors refer to most vitamin supplements as "expensive urine" - only 15-30% of any pills are absorbed anyway, and what can't be used is eliminated (hence the "urine" reference). Many people supplement, yet they still get tested and are found deficient in one element or another. So it doesn't matter what you swallow, it matters how much of that is in an absorbable form.
So mixing and matching individual supplements is a pretty efficient way to spend money with limited benefit. In the food science industry, we call that "playing kitchen chemist" which means just grabbing things off the shelf at the health food store (which makes far more money that way) and mixing them together according to what we read in an article, saw on tv, or heard from a doctor (who very likely had zero nutritional coursework in medical school). You really want the science to be done by food scientists, not marketers or businesspeople.
The science of cellular nutrition and the clinical data support comprehensive supplementation in liquid form (not premixed, so not purchased as a liquid), and with well over 70 ingredients (vitamins, minerals, trace elements, and more). You also want to look for something without warning labels (meaning you cannot overdose because everything is balanced as well as safe - all ingredients should be on the FDA "GRAS" list, meaning "Generally Recommended As Safe). The awarding of a government patent is also an excellent sign, meaning the product is proven safe, effective and unique. If products can be sold in countries with a much stricter FDA than ours, that's a great sign as well.
I'm not aware of anything you can purchase in stores but there are some things available on line, so you have to do some investigation. A good company will assign a consultant to you to answer questions and will make its research team available for questions. It can, and should, be made very simple - not a lot of combinations and mixing/matching.