Most people know their diet could use an upgrade, but in practice, many still aren’t getting all the nutrients their bodies rely on from food alone.
Three of the most talked-about immune-support nutrients are zinc, vitamin C, and vitamin D, yet plenty of adults fall short on one or more of them.
Low zinc and vitamin C intake has been associated with higher stress and inflammation. Vitamin D can be an even bigger challenge because your body makes it from sunlight—so if you’re not outside regularly, your levels may be lower than ideal.
That’s one reason multivitamins remain popular.
About one in three Americans already takes a multivitamin each day. They’re not a cure-all, but research suggests they can help shore up nutrient status. For example, studies indicate that in older adults, daily multivitamin use can raise blood levels of zinc and vitamin C in as little as 12 weeks.
Your energy may feel more consistent.
One study involving healthy, active adults found that after a month of taking a daily multivitamin, men experienced increased energy during exercise. Women in the same research reported lower stress and less mental fatigue.
Dietitian Melissa Mitri explained the potential difference supplementation can make in an interview with Eating Well: “People who begin to supplement with a multivitamin and have a specific deficiency may feel a difference in their energy level.”
Iron is a well-known factor in fatigue, and the study also reported that participants taking multivitamins had improved iron stores after one month.
There may also be cognitive benefits over time. In a three-year study that followed more than 2,600 adults, researchers observed that daily multivitamin use was linked with better executive function—the mental skills involved in memory, attention, planning, and focus.
It’s not going to make you brilliant overnight.
Still, for older adults who notice occasional forgetfulness or find it harder to concentrate, building a multivitamin into a daily habit could be a practical step.
If you’re pregnant—or trying to become pregnant—supplementation can be especially important.
Prenatal vitamins are a dedicated form of multivitamin and typically include folic acid, iron, DHA, choline, and iodine, which support fetal development. Iron deficiency is common in pregnancy, with roughly 28 percent of women becoming iron-deficient during the last trimester alone.
Evidence suggests that taking a multivitamin during pregnancy may lower the risk of anemia, gestational diabetes, and neural tube defects. The American College of Obstetrics and Gynecology recommends using prenatal vitamins both before conception and during pregnancy.
Nutrition can also play a meaningful role in mental wellbeing.
One review found that getting enough B vitamins—commonly included in multivitamins—may help ease symptoms of depression and anxiety and could also support sleep. Separately, studies have reported that higher-dose vitamin D supplementation can improve anxiety symptoms for some people.
It’s not a substitute for professional mental health care, but it’s another reason some people choose to add a multivitamin to their routine.
Even with those potential upsides, multivitamins aren’t essential for everyone, and it’s worth approaching them thoughtfully.
Registered dietitian Kelsey Lorencz told Eating Well: “For most people, a multivitamin isn’t necessary. But for older adults, people experiencing low appetite or difficulty eating a balanced diet, from illness or even pregnancy, a multivitamin can help fill in nutrition gaps.”
If you choose to take one, Mitri advises selecting options that provide nutrient amounts near 100 percent of the recommended daily allowance rather than megadoses, which can trigger side effects such as nausea, stomach cramps, or digestive discomfort.
It’s also wise to check for third-party testing marks like USP or NSF verification, which signal that the product meets quality standards and contains what the label claims.
As always, talk with your doctor before starting a supplement—especially if you take prescription medications or manage an ongoing health condition.
A balanced diet is still the best baseline. But for many people, a daily multivitamin can be a simple way to cover common nutritional gaps.