Old research said taking multivitamins doesn’t make you healthier. But new studies show these vitamins may be important for our brains.

Ten years ago, an article about multivitamins appeared in the Annals of Internal Medicine, a well-respected medical journal. The researchers had looked at past studies about vitamins and minerals and concluded that there was no evidence that nutritional doses (meaning doses up to the Recommended Daily Allowance (RDA)--not megadoses) had any effect on preventing heart disease, cancer, or death in healthy people who didn’t have nutritional deficiencies.

In other words, the daily vitamins were useless for most people. The journal’s editors made the point clear in an editorial they wrote in the same issue. The title: "Enough Is Enough: Stop Wasting Money on Vitamin and Mineral Supplements."

And in 2022, a review of 84 separate studies by the U.S. Preventive Services Task Force came to the same conclusion.

Case closed, right? Not so fast. It turns out the vitamins might be good for people—especially older people—after all.

A new finding on multivitamins

Recent studies at Harvard, Wake Forest, and Columbia Universities found that taking multivitamins can slow the pace of age-related memory loss – by as much as 3 years! Adam Brickman, a neuropsychology professor at Columbia and co-author of one of the studies, discussed the findings with NBC News.

“Cognitive change and memory loss are a top health concern for older adults,” he said. “And we don’t have many strategies to mitigate the changes that come with aging. So it’s encouraging that a supplement can help address one of the main health concerns older adults have.”

Learn 8 more ways to sharpen your memory.

Scientists need to do more research to identify which specific nutrients are helpful for boosting memory. Based on earlier studies, they consider four to be likely candidates:

Vitamin B

There are eight different B vitamins with different roles in the body, but one in particular – B12 – has been shown to be important for brain and nerve cells. Not having enough of this vitamin may put you at risk of dementia.

Vitamin B12 is contained in foods that come from animals, like fish, meat, eggs, and dairy products. But both age and certain medications, like protein pump inhibitors, can lessen your body’s ability to absorb the vitamin from the food. That’s why many experts recommend that people over 50 eat foods fortified with B12, such as some breakfast cereals,  or take B12 supplements.

Vitamin D

You probably know Vitamin D helps your body absorb calcium from food, which is important for preventing bone loss. But this vitamin has many other roles, including protecting against illness and infection and maybe even warding off cancer. And new studies are finding that low vitamin D levels may be linked to memory problems and dementia.

Our bodies make most of this vitamin from sunlight, and not many foods naturally contain vitamin D. Supplements may be the best way for many of us to get enough of this important nutrient.

Learn about the latest thinking on Vitamin D.

Magnesium

This mineral helps regulate blood sugar and blood pressure and helps keep your heartbeat steady. Recently researchers have found that magnesium plays a role in brain health and might help reduce or delay the onset of memory problems and dementia.

Magnesium is found in plant foods like legumes, dark green leafy vegetables, nuts, seeds, whole grains, and fortified cereals. It’s also found in fish, poultry, and beef.

Zinc

Like magnesium, this mineral has many roles, affecting your skin and bones as well as your digestive, central nervous, and immune systems. When older adults don’t get enough zinc, there can also be changes in memory and cognitive function.

The richest food sources of this mineral are meat, fish, and other seafood. Fortified breakfast cereals also contain zinc and are the major source of the mineral for many people.

More about multivitamins

Of course, many people find it easiest to simply take a multivitamin. Most multivitamins contain a combination of about 26 different vitamins and minerals. And because multivitamins usually contain the RDA of vitamins and minerals—and not megadoses, which are many times more—they are generally considered safe. Even so, there are some things to be aware of.

Vitamin and mineral supplements are NOT a substitute for a healthy diet that includes plenty of fruits and vegetables, whole grains, healthy fats, and lean proteins. Most health professionals still believe that eating nutritious food is the best way for your body to get the vitamins and nutrients it needs.

Does Medicare cover nutritionists?

But because many diets aren’t perfect, and because some nutrients may be difficult to get from food, vitamin and mineral supplements can fill in the gaps for some people.

For instance, people who are following special diets, such as low-calorie, keto, or vegan, may need to supplement, as well as people with certain medical conditions like Crohn’s disease, ulcerative colitis, celiac disease, or past gastric bypass surgery. Also, the body’s ability to absorb nutrients from food does get worse with age, and many medications affect how the body absorbs nutrients. So it’s not uncommon for older adults to have low levels of some vitamins or minerals.

While most daily multivitamins are safe, some vitamins can have harmful effects when taken at high doses. High levels of magnesium, for example, can cause muscle weakness, fatigue, low blood pressure, and breathlessness. Some research has even suggested that too much magnesium, just like too little, can raise the risk of dementia.

It’s important that you talk to your doctor before adding any vitamin or mineral supplements to your routine. Depending on your health and what medications you take, your doctor might want to measure your blood levels of vitamins and minerals before recommending a supplement.

And if you do decide to try a supplement, make sure to look for certifications that can help make certain you’re buying a quality product. The USP certification is a good one to look for.

Find out how to save money on vitamins and more with store brands.

Medicare and your cognitive health

Original Medicare generally doesn’t cover vitamins and minerals. But these supplements might be covered under Medicare Part B or D if they’re being used to treat an illness or medical condition. Of course, you’ll find coverage for tests and treatments for dementia in Original Medicare, as well.

Many Medicare Advantage plans offer a monthly over-the-counter allowance that you can use toward vitamin and mineral supplements. Most Medicare Advantage plans also often provide coverage for gym memberships – and exercise has been shown to reduce the risk of dementia.

Check out policies available in your area with our easy-to-use Find a Plan tool.

Additional resources

• ClearMatch Medicare: Find a Medicare Plan
• NBC News: Multivitamins May Help Slow Loss of Memory as People Get Older
• GoodRx: 8 Tips for Choosing Safe Over-the-Counter Supplements