The U.S. Dietary Guidelines have always asserted that our nutritional needs should be met mainly via the foods we eat. The current 2020-2025 guidelines, though, acknowledge that supplements may be useful for providing nutrients you may not be getting enough of—especially when your diet has some gaps.
“As a nation, we are overfed and undernourished,” says Marci Clow, R.D.N., a dietitian at Rainbow Light, maker of food-based multivitamins and supplements. In a perfect world, our diets would be made up of nutrient-dense whole foods (fruits and vegetables, whole grains, lean proteins, and healthy fats). But that’s just not the case: “Statistics show that about three-fourths of the population has an eating pattern that is low in vegetables, fruits, dairy and healthy sources of fat,” says Clow.
And let’s be honest—between busy schedules, grab-and-go meals, and the occasional (okay, frequent) takeout order, most of us aren’t exactly eating picture-perfect plates every day.
That said, it seems there’s a constant debate over whether or not we all need a daily multivitamin. While a daily multivitamin isn’t a magic bullet, there are plenty of situations in which we could all benefit from one. Here’s a look at some common scenarios where a multi might be worth considering.
If You Cut Out a Food Group
“Anyone who cuts out particular food groups or goes on a diet that cuts out certain foods—such as the Paleo Diet—may benefit from a multivitamin,” says sports dietitian Marie Spano, R.D., C.S.C.S. With Paleo, you might miss out on calcium and vitamin D, specifically, she explains. (Calcium is most commonly found in dairy, while vitamin D is often added to milk and cereal products—all no-no’s for Paleo.)
Other Diets That May Create Gaps
It’s not just Paleo, either. Here are a few other eating patterns that might leave you short on certain nutrients:
- Keto or low-carb diets: When you cut back on grains and fruits, you might miss out on B vitamins, fiber, and certain minerals like potassium.
- Vegan or vegetarian diets: Plant-based eating is fantastic, but it can make getting enough B12, iron, zinc, and omega-3s a bit trickier.
- Gluten-free diets: Many fortified cereals and breads contain added B vitamins and iron—skip those, and you might need to make up the difference elsewhere.
Another example: If you cut back on red meat, you may miss out on iron and vitamin B12, says Spano. (Iron helps transport oxygen throughout our bodies, while vitamin B12 supports energy production, according to the National Institutes of Health.) Many women in the U.S. are iron deficient, she adds—around 10 percent of white women and 20 percent of black and Hispanic women, says the American Academy of Family Physicians.
The bottom line? If your eating style eliminates entire food groups—whether for health reasons, ethical choices, or personal preference—a multivitamin can help fill in those nutritional blanks.
If You’re Pregnant
The surge of pregnancy hormones can cause nausea and lack of appetite—and adequate nutrient intake during pregnancy may become a challenge for many women, Clow says. “Consuming a varied diet should be the first and foremost way for providing nutrients during gestation; however, medical research shows that a prenatal multivitamin can play a critical role in supporting overall health for both mother and baby.”
What Makes Prenatals Different
While a regular multivitamin might be consumed to fill in dietary nutrient gaps, prenatal multivitamins are formulated to meet specific increased nutrient needs that accompany pregnancy, Clow explains. “Folic acid and iron are two of the most critical nutrients to fuel a healthy pregnancy—and are both recommended at nearly twice the level found in a standard multivitamin.”
Here’s why those nutrients matter so much:
- Folic acid (folate): Helps support the healthy development of baby’s brain and spine, especially in those early weeks.
- Iron: Supports the increased blood volume during pregnancy and helps prevent fatigue and anemia.
- DHA: Many prenatals now include this omega-3 fatty acid to support baby’s brain and eye development.
And if morning sickness has you struggling to keep much down? A prenatal multi can provide some peace of mind that you’re still getting those essential nutrients even on days when crackers and ginger ale are all you can manage.
Planning to become pregnant? Most healthcare providers recommend starting a prenatal three months before you even start trying, so your body has time to build up those nutrient stores.
If You Live in the North
In protecting yourself from the sun (hello, SPF) you might also be picking up a vitamin D deficiency, says Arielle Levitan, M.D., author of The Vitamin Solution. According to a study published in Nutrition Research, about 40 percent of the U.S. population could be deficient in the vitamin.
The Sunshine Vitamin Struggle
“Those with limited sun exposure, people living in northern latitudes, and people with darker skin tones should consider extra vitamin D,” says Clow.
Think about it: if you live somewhere with long, gray winters (we’re looking at you, Seattle, Minneapolis, and Boston), your skin simply isn’t making much vitamin D from October through April. Add in the fact that most of us spend our days indoors anyway, and it’s easy to see how deficiency becomes common.
Here’s who might want to pay extra attention to their D levels:
- People who work indoors during daylight hours
- Those who consistently wear sunscreen (which is still important!)
- Older adults, whose skin becomes less efficient at producing vitamin D
- Anyone with darker skin tones, which naturally provide more sun protection
- People who cover most of their skin for religious or cultural reasons
Since vitamin D plays a role in bone health, immune function, and even mood, making sure you’re getting enough is worth the effort—whether that’s through a multivitamin, a standalone vitamin D supplement, or both.
If You’re a Big Exerciser
Research published in Nutrition Reviews suggests almost half of Americans do not get ample magnesium (which plays a role in over 300 biochemical reactions in your body) from their diets. Plus, magnesium is one of the minerals you lose when you sweat, says Levitan. That means fitness buffs who go hard and sweat hard, and endurance athletes who train for hours at a time, may be at greater risk for magnesium insufficiency.
What Active Bodies Need
But it’s not just magnesium. When you’re exercising regularly, your body has higher demands across the board:
- B vitamins: Help convert food into energy—and when you’re burning through more fuel, you need more of these helpers.
- Iron: Especially important for women athletes, as it supports oxygen delivery to working muscles.
- Zinc: Supports immune function and recovery—key when your body is constantly rebuilding after tough workouts.
- Electrolytes: Sodium, potassium, and yes, magnesium all leave your body through sweat.
Whether you’re a weekend warrior, a daily gym-goer, or training for your first marathon, a multivitamin can help ensure your body has what it needs to perform, recover, and keep showing up.
Not sure if your routine counts as “big exercise”? If you’re sweating through your shirt a few times a week or training for more than an hour at a time, your nutrient needs are likely higher than someone who’s mostly sedentary.
As You Age
As we get older, we’re less able to absorb certain nutrients, says Clow. For example, B12 requires a substance called ‘intrinsic factor,’ which is secreted by stomach cells in order to be absorbed. Our production of this substance decreases as we age, she says. According to the National Institute on Aging, most people start to have trouble absorbing B12 around age 50.
Nutrients That Become Harder to Get
Not to mention, conditions and circumstances often related to aging—like use of prescription medications, onset of degenerative diseases, and increased isolation—can also put the elderly at risk for vitamin and mineral deficiencies, says Clow.
Here’s what tends to become trickier to maintain as the years go by:
- Vitamin B12: Absorption drops significantly, which can affect energy levels and cognitive function.
- Vitamin D: Skin becomes less efficient at making it from sunlight, and time spent outdoors often decreases.
- Calcium: Bone health becomes even more important as we age, but dietary intake often falls short.
- Magnesium: Many older adults don’t get enough, and certain medications can deplete it further.
For adults 50 and older, a multivitamin formulated for your age group can be especially helpful. These formulas typically contain higher amounts of B12 and D, adjusted iron levels (since needs often decrease after menopause), and other tweaks designed for aging bodies.
The good news? Supporting your nutritional needs as you age doesn’t have to be complicated. A well-chosen multi, combined with a reasonably balanced diet, can help you maintain energy, support bone health, and keep your immune system strong.
But Remember…
As a rule of thumb, touch base with your doc before taking a multivitamin. A healthcare professional can make sure that medicines or supplements you already take won’t interfere with a daily multi, says Clow. (Common heartburn and diabetes medications, for example, can interfere with the absorption of magnesium and vitamins B12 and D, Levitan says.) And since everyone’s nutritional needs are different, consult with a doc or nutritionist for more info about which supplement may be best for you.
A Few More Things to Keep in Mind
Here are some other tips to help you get the most out of your multivitamin:
- Timing matters: Some vitamins absorb better with food (especially fat-soluble ones like A, D, E, and K), so taking your multi with a meal is usually a good idea.
- More isn’t always better: Stick to the recommended dose. Taking extra won’t give you extra benefits—and with some nutrients, it can actually cause problems.
- Quality counts: Look for brands that use third-party testing to verify what’s actually in the bottle. Not all supplements are created equal.
- It’s a supplement, not a substitute: A multi is meant to fill gaps in your diet, not replace whole foods. Keep eating those fruits and veggies!
If you’re not sure where to start, The Vitamin Shoppe’s Health Enthusiasts can help point you in the right direction—whether you’re looking for a general daily multi, something specific for your life stage, or just have questions about what might work for your situation.
At the end of the day, a multivitamin isn’t a magic solution—but for many of us, it can be a simple, affordable way to support overall wellness and give our bodies a little extra nutritional backup.