News

Multivitamins May Shorten Duration of Illness in Older People, Study Shows

old person holding vitamins and a glass of water

Moyo Studio / Verywell 

Key Takeaways

  • Older adults taking a multivitamin, zinc, and vitamin C had shorter periods of illness and less severe symptoms, a recent study concludes.
  • Zinc and vitamin C have been linked to better immune function in previous studies.
  • Despite these findings, more evidence is needed for multivitamins without diagnosed deficiencies, some experts believe.

Older adults who took a multivitamin and a mineral supplement with zinc and vitamin C experienced illness for a shorter time and with less severe symptoms than those taking a placebo, a study published in Nutrients concludes.

The results of the study are helpful in the context of individuals with nutrient deficiencies, but more research on multivitamins is required before any widespread recommendation can be made.

Zinc and Vitamin C

Researchers from Oregon State University's Linus Pauling Institute looked at 42 healthy participants, aged 55 to 75, and split them into two groups for 12 weeks. One received a daily placebo, while the other had the multivitamin and mineral combination.

The number of sick days within that 3-month timeframe was lower for the supplement group than the placebo group—averaging three days of illness, compared to six for the placebo participants.

Zinc and vitamin C were chosen as separate supplements because they have been shown to help immune function, researchers noted, and they may have played a role with less severe symptoms when the supplement participants did get sick.

Research Limitations

The recent study's limitations should be kept in mind, especially the small number of participants, and short timeframe—which don't negate the study findings, but do highlight how more research needs to be done before a large-scale recommendation can be given, such as "everyone should take a multivitamin."

For that guideline to be in place, there would have to be considerably more compelling evidence, according to Michael Devine, MD, an internist and geriatrician.

"To date, there is no substantial evidence to suggest any measurable benefit of taking multivitamins for the average person, who is not known to have specific vitamin or mineral deficiencies," he says. Although deficiencies develop for many people as they get older, they're not an automatic part of aging.

Michael Devine, MD

To date, there is no substantial evidence to suggest any measurable benefit of taking multivitamins for the average person, who is not known to have specific vitamin or mineral deficiencies.

— Michael Devine, MD

Based on the concentrations of the various vitamins and minerals in a typical multivitamin, there is very low risk of harm, Devine adds, but there is also questionable benefit. However, the idea of multivitamins as a kind of nutritional insurance policy is hard to dispel, even for Devine himself.

"I'm transparent with patients about the lack of empirical evidence supporting their use, but also keep an open mind to account for differences in how an individual's body may respond," he says. "Many patients report feeling improvement when taking one, while others don't. Is it a placebo effect? Maybe. But full transparency is that I still personally take a multivitamin daily."

More Evidence Needed with All Supplements

The need for more substantial evidence doesn't apply only to multivitamins, but across a whole range of supplements, from fish-oil pills to calcium, says researcher Safi Khan, MD, of West Virginia University.

Safi Khan, MD

If you're taking supplements as a way to improve your health, just know that the evidence for that is weak. A better approach might be to simply focus more on your eating, especially fruits and vegetables, to try to eliminate the nutritional gaps.

— Safi Khan, MD

A meta-analysis he led, published in Annals of Internal Medicine in 2019, reviewed data from 277 clinical trials that involved 24 supplements—multivitamins, specific vitamins and minerals, omega-3s, and antioxidants—as well as eight diets, including the Mediterranean, reduced salt, and low-fat. In all, nearly a million participants were included.

The research included only randomized, controlled trials rather than observational studies that rely on participant recall, which can be problematic for accurate results.

They found a few tactics that provided a modest benefit: reduced salt intake, omega-3 supplements, and taking folate proved to reduce some risk for heart attacks and stroke. But the rest of the supplements didn't show any association with improved cardiovascular health or longer life.

"In general, if you're concerned about deficiencies, it's worth getting that checked to make sure that's actually true," says Khan. "But if you're taking supplements as a way to improve your health, just know that the evidence for that is weak. A better approach might be to simply focus more on your eating, especially fruits and vegetables, to try to eliminate the nutritional gaps."

What This Means For You

Just because there isn't overwhelming evidence for multivitamins—or most other supplements—doesn't mean they're worthless, since they can be helpful if you have deficiencies. However, knowing about those gaps are important since they may be a sign of a larger problem.

For example, a low amount of iron could indicate anemia, or an iodine deficiency might be a thyroid problem. Talk with your doctor about getting your vitamin and mineral levels checked, particularly if you're older.

Was this page helpful?
Article Sources
Verywell Fit uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Fantacone ML, Lowry MB, Uesugi SL, et al. The effect of a multivitamin and mineral supplement on immune function in healthy older adults: A double-blind, randomized,controlled trialNutrients. 2020;12(8):E2447. Published 2020 Aug 14. doi:10.3390/nu12082447

  2. Khan SU, Khan MU, Riaz H, et al. Effects of nutritional supplements and dietary interventions on cardiovascular outcomes: An umbrella review and evidence map [published correction appears in Ann Intern Med. 2020 Jan 7;172(1):75-76]. Ann Intern Med. 2019;171(3):190-198. doi:10.7326/M19-0341

Related Articles