What Are the Best Supplements to Take?

What is the best supplement to take every day?

There is no single best supplement for everyone to take every day. A supplement earns a place when it addresses a specific need; without one, adding products can increase costs and, at high total intakes, risks.

The NIH Office of Dietary Supplements describes uses tied to defined circumstances: folic acid can reduce the risk of certain birth defects, calcium and vitamin D support bone health, and an AREDS formula can slow further vision loss in some people with age-related macular degeneration. These are specific purposes, not proof that everyone benefits from a daily product.

Evidence for broad disease prevention is less encouraging. The U.S. Preventive Services Task Force reviewed 84 studies involving 739,803 participants and concluded that vitamin and mineral supplements had little or no benefit for preventing cancer, cardiovascular disease, or death. It recommends against beta-carotene or vitamin E supplements for those preventive purposes; beta-carotene was associated with increased lung cancer risk and cardiovascular mortality in the review.

A useful starting point is the gap, not the bottle. Ask what foods are missing or avoided, whether a health condition affects absorption, and what outcome the supplement is meant to support. If there is no clear answer, a product is not automatically worthwhile.

What are the 5 most important supplements to take?

The five most relevant options depend on who is asking; the evidence supports targeted consideration, not a ranked list for everyone. These examples show where a specific need can change the decision.

1. Vitamin B12: Plant foods do not naturally contain B12, though fortified cereals and nutritional yeast can provide it. The NIH fact sheet identifies dietary deficiency, absorption problems, gastrointestinal surgery, pernicious anemia, and prolonged use of some medicines as risk factors. A blood test can help assess status when indicated.
2. Folic acid: NIH lists reducing the risk of certain birth defects as a specific use. That purpose is distinct from taking a general multivitamin for disease prevention.
3. Calcium and vitamin D: These nutrients support bone health, but the source material does not establish that every healthy adult needs them as supplements. Diet, individual risk, and clinical context shape the decision.
4. AREDS formula: This formula can slow further vision loss for some people with age-related macular degeneration. The benefit is tied to that condition, not to general eye health in everyone.
5. Omega-3s: People who rarely eat fish may ask about alternatives. Algal oil is a plant-based source of long-chain omega-3s, while flaxseed, chia seeds, walnuts, and canola oil contain ALA. NIH reports that conversion from ALA to EPA and then DHA is limited, with rates below 15%; product labels vary in omega-3 types and amounts.

A multivitamin is not a shortcut around this assessment. NIH summarizes evidence from 78 randomized trials involving 324,837 participants: vitamin and mineral supplements had little or no benefit for preventing cancer, cardiovascular disease, or death, apart from a possible small reduction in cancer risk with multivitamins. A separate cohort study found that multivitamins increased the share of participants with adequate intake of studied nutrients, while some users also had excessive intakes of selected nutrients.

Do healthy adults need supplements if they eat a balanced diet?

Healthy adults who eat a varied diet do not automatically need supplements. NIH notes that supplements can address nutrient gaps but cannot replace a varied, nutritious diet.

The case for assessing supplementation is stronger when food choices are restricted, calorie intake is low, or a condition impairs digestion or absorption. Strict vegetarians and vegans are among the groups NIH identifies as potentially more likely to benefit from a multivitamin/mineral product. For B12 in particular, naturally occurring sources are animal foods; fortified foods are another source.

Use this decision path:

1. Map the diet. Identify foods or food groups routinely excluded, not just a few imperfect meals.
2. Check personal risk. Consider known absorption problems, relevant health conditions, and medicines that may affect nutrient status.
3. Name the question. Identify the suspected gap or evidence-backed purpose before choosing a product.
4. Discuss next steps. A clinician can help decide whether dietary changes, testing, or a supplement fits the situation.
5. Recheck the full intake. Include multivitamins, single-nutrient products, and fortified foods; combining them can raise totals above tolerable upper limits.

This sequence prevents a common mistake: treating a broad product as insurance while overlooking overlap between products. In the U.S. cohort data summarized by NIH, multivitamin users were more likely to meet adequate intake for the nutrients studied, but excessive intake of some nutrients also occurred. More coverage is not always better coverage.

Should I get blood tests before choosing supplements?

Blood tests are useful when a clinician has a reason to check a particular nutrient; the sources do not support testing everyone for every nutrient before any supplement decision. Testing is most useful when it answers a defined question, such as whether a risk factor has led to low status.

Vitamin B12 illustrates the role of context. NIH says serum or plasma B12 below about 200–250 pg/mL is generally considered subnormal, though laboratory cutoffs vary; methylmalonic acid can help confirm deficiency when B12 results are borderline. Those figures are from the NIH fact sheet, which does not give a publication year in the supplied research notes. A result should be read alongside symptoms, risk factors, the laboratory’s range, and clinical judgment.

Testing also prevents guessing in the other direction. Hair thinning or brittle nails can occur with biotin deficiency, but these signs do not establish that deficiency is present; NIH says biotin deficiency is rare. High biotin intake can interfere with lab assays, including thyroid tests, so tell the clinician and laboratory about supplements before testing.

Before buying, inspect the label. The Supplement Facts panel lists serving size and ingredient amounts. Compare the listed ingredients across products, watch for nutrients duplicated in a multivitamin and separate formulas, and be wary of unsupported blend claims that hide how much of each ingredient a serving contains.

Independent seals can add a quality check. NIH names USP and NSF as organizations that test products for identity, ingredients, and contaminants. Their seals do not establish that a supplement works or is safe for a particular person, and the FDA does not approve supplements for effectiveness before they are marketed.