Do I need supplements at all if I eat a healthy diet?

For most people who eat a varied diet, the answer to most of the supplement shelf is no. The Nordic Nutrition Recommendations (NNR2023) start from the position that vitamin and mineral needs should be met primarily through food, and that supplements are warranted only when the diet or life situation creates a genuine shortfall.

In 2022 the US expert panel USPSTF reviewed the evidence for whether multivitamins and single vitamin or mineral supplements prevent cardiovascular disease or cancer in otherwise healthy adults. It concluded that the evidence is insufficient for most supplements, and it recommends against two of them: beta-carotene, which raised lung cancer risk in smokers, and vitamin E, which showed no benefit. The systematic review behind it (O'Connor and colleagues) found only small or no effects of multivitamins on illness and death.

A large cohort study in 2024 followed roughly 390,000 healthy Americans for up to 27 years. Once the researchers accounted for the fact that healthier people take supplements more often, they saw no lower mortality among daily multivitamin users.

None of this means no supplement has a place. A few are well grounded in specific situations: vitamin D at northern latitudes through the winter, B12 for anyone eating fully plant-based, folate during pregnancy, and iron for a documented deficiency. The point is that the list is short and need-driven, not a general insurance policy taken just in case.

Supplements sell a feeling of control. Swallowing a pill is a concrete act that feels like doing something for your health, while "eat varied and you already have what you need" offers no such receipt. Deficiency logic plays along: the fear of missing a nutrient weighs heavier than the small chance a supplement is actually needed. And the incentives point one way. Supplements are a multibillion-dollar industry that profits from selling more bottles, not from saying the food is enough. So the marketing frames supplements as general insurance, and healthy people who feel fine anyway read it as proof the pill helped.

Start with the food, not the bottle. If you eat a varied diet, the baseline is that you already get most of what you need. Add a supplement when there is a reason: vitamin D through the dark months, B12 if you eat fully plant-based, or something your healthcare provider has found you are short on. Skip beta-carotene and high-dose vitamin E as general protection, and put the money toward vegetables, legumes and fish rather than a shelf of pills taken just in case.