Many adults and children take a daily multivitamin as part of their overall health strategy. However, decades of research have produced mixed findings on whether multivitamins reduce the risk of major health outcomes. As a result, some experts assert that water-soluble vitamins produce little more than expensive, neon-colored urine.

More recent studies—particularly those using improved research designs—are beginning to challenge this notion. While multivitamins are not a cure-all, they may offer subtle but measurable benefits, especially in certain populations.

• In a 2026 study analyzing data from the COSMOS trial involving 958 older adults, researchers found that participants who took a daily multivitamin for two years experienced slower biological aging—by about four months—compared to those taking a placebo. The multivitamin group also had lower levels of inflammatory markers and performed better on cognitive assessments, suggesting potential benefits for both physical and brain health.
• An August 2020 study of 42 middle-aged and older adults found that those taking a daily multivitamin experienced less severe illness symptoms and shorter illness duration than those given a placebo. Many nutrients commonly found in multivitamins—such as vitamins C, vitamin D, and zinc—are known to support immune function.
• In a group of 1,708 heart attack survivors, researchers observed that those given a high-dose multivitamin had a 54% lower risk of adverse cardiovascular outcomes compared to those given a placebo.
• An analysis of nearly 100,000 women found that multivitamin use during pregnancy was associated with reduced risks of several birth defects, including neural tube, cardiovascular, urinary tract, and limb abnormalities.

A more modern perspective is that multivitamins may not be universally necessary—especially for individuals who consume a well-balanced, nutrient-dense diet rich in fruits, vegetables, whole grains, lean proteins, and healthy fats. For these individuals, additional supplementation may offer little added benefit. However, for older adults, individuals with dietary restrictions, chronic conditions, or increased nutritional demands, a daily multivitamin may serve as a practical and low-risk way to help close nutritional gaps.

As research continues to evolve, the most balanced conclusion may be that multivitamins are neither a miracle solution nor a waste, but rather a tool that can be useful in the right context.