For general health, a basic approach would be:

SupplementWhen it may make senseMultivitaminReasonable “insurance” if your diet is inconsistent, but not a substitute for good food. Evidence is not strong that multivitamins prevent heart disease or cancer in healthy nonpregnant adults. Vitamin DWorth discussing or testing, especially if you get little sun exposure, live in the Northeast, or have low levels. Too much can be harmful, so avoid megadoses. B12More important if you are over 50, vegan/vegetarian, take metformin or acid-reducing medication, or have absorption issues. NIH notes people over 50 often absorb B12 better from fortified foods or supplements than from natural food sources. Omega-3Consider if you rarely eat fatty fish. Food sources like salmon, sardines, and trout are usually better than pills.CalciumBetter from food when possible. Consider supplementing only if you consistently fall short through diet.MagnesiumMay help some people with cramps, constipation, or sleep, but it can interact with some medications and cause diarrhea.

I would avoid routine high-dose supplements, “detox” products, fat burners, testosterone boosters, and most herbal blends unless your doctor or a registered dietitian recommends them. Also avoid taking vitamin E or beta-carotene for heart disease or cancer prevention; USPSTF recommends against those uses in nonpregnant adults.

Most important: supplements are not regulated like prescription drugs. The FDA says it generally does not approve dietary supplements for safety and effectiveness before they are marketed, so quality varies. Look for third-party testing such as USP or NSF, and tell your doctor or pharmacist what you take because supplements can interact with medications.

A sensible “safe” starter stack for many adults, after checking with a clinician, is simply: a modest multivitamin, vitamin D if low, and B12 if risk factors apply. The rest should be based on diet, symptoms, medications, and bloodwork.