This question is about Nutrition
Many people can benefit from a multivitamin to fill nutrients gaps. While you can get many nutrients from a well-balanced diet, many people fall short of the daily recommendation for several nutrients, and a multivitamin can serve as an insurance policy.
This is especially true for people with increased nutrient needs, impaired nutrient absorption, inadequate dietary intake, and/or with certain pre-existing medical conditions [1
. However, even those who eat a healthful diet rich in fruits, vegetables, whole grains, healthy fats, and lean protein can still fall short on some nutrients such as vitamin D.
Furthermore, some groups have higher needs for specific nutrients (such as in hypermetabolic states, heavy training, pregnancy and/or lactation) and can struggle to meet nutrient needs from food alone. For these people a daily multivitamin can be helpful for avoiding deficiency and optimizing health [ 2
Ward E. Addressing nutritional gaps with multivitamin and mineral supplements. Nutr J. 2014;13:72. Published 2014 Jul 15. doi:10.1186/1475-2891-13-72
Rautiainen, S., Manson, J. E., Lichtenstein, A. H., & Sesso, H. D. (2016). Dietary supplements and disease prevention - a global overview. Nature reviews. Endocrinology, 12(7), 407–420. https://doi.org/10.1038/nrendo.2016.54