- Many people take a daily multivitamin to promote good health and prevent chronic disease.
- Taking a daily multivitamin may not extend the lifespan of generally healthy adults, according to a new study from the National Institutes of Health.
- While multivitamins may not extend the lifespan of healthy adults, experts say they could still be beneficial for certain groups.
A new study analyzing data from nearly 400,000 participants in the United States over 20 years suggests that taking a daily multivitamin over the long term may not extend the lifespan of healthy adults.
Approximately 33% of U.S. adults take a daily multivitamin to maintain overall health, with the belief that it can help prevent disease and contribute to a longer, healthier life.
Despite their widespread use, studies to date have not found enough evidence to determine whether multivitamins actually have a positive effect on longevity.
Aiming to fill this research gap, researchers at the National Institutes of Health (NIH)
They took into account influencing factors such as healthy diet and lifestyle, and reverse causation, with people in poor health starting to use multivitamins.
A new NIH study published in 2011:
However, don’t throw away your multivitamins just yet, as they may still be beneficial for certain individuals and this observational study has some limitations.
The new NIH study aimed to evaluate the association between multivitamin use and mortality related to chronic diseases, specifically cardiovascular disease and cancer. It also sought to explore potential factors and biases that may affect our understanding of this association.
The researchers conducted their analysis using data from three large cohort studies in the United States.
Their pooled analysis included 390,124 generally healthy adult participants, aged 18 to 74 years at baseline, with no history of major chronic diseases.
Participants self-reported frequency of multivitamin use (e.g., never, daily) and their use of other vitamins, minerals, and supplements.
Based on this data, the researchers divided the participants into three groups.
- Do not take multivitamins
- Non-daily use of multivitamins
- Daily multivitamin intake
The researchers also took into account participants’ self-reported dietary history.
Participants were followed for more than 20 years, with some being followed for up to 27 years.
During the study period, 164,762 deaths were recorded among participants, of which approximately 30% were due to cancer, 21% to heart disease, and 6% to cerebrovascular disease.
Among those who take a daily multivitamin, nearly half are women, compared with about 40% who are non-users.
People who took a daily multivitamin were more likely to also take other individual supplements, have a lower BMI, and have a better quality diet than non-users.
These findings are consistent with previous research suggesting that multivitamins are somewhat popular among women, and that those who take them regularly may be more health conscious in general.
Multivitamin use did not differ significantly by race, ethnicity, or family history of cancer.
Overall, the researchers found no evidence that regular use of multivitamins extends the lifespan of healthy adults.
In fact, in a pooled analysis, people who took a daily multivitamin supplement had a 4% higher risk of death compared with those who did not.
However, the hazard ratio values suggest that there was no difference in survival between the two groups. This was observed for overall mortality and for specific causes such as heart disease, cancer, and cerebrovascular disease.
Despite the lack of evidence on longevity, the researchers suggest that regular consumption of a multivitamin may be associated with other important outcomes related to healthy aging, such as supporting cognitive function in older adults.
The study has some notable limitations, including that it is observational and therefore cannot establish causality, and that it may not have taken into account factors that may influence the results, such as access to health care services.
The study authors also noted that they were not able to define a timeline for the relationship between multivitamin use and mortality risk, how risk might change over time, or the overall effect over a person’s lifetime.
Additionally, the study involved exclusions based on health status and lacked diversity, meaning findings cannot be generalized to the broader population.
Healthy adults who consume adequate dietary nutrients may not benefit from the use of a multivitamin, but for individuals in certain populations and age groups, taking a daily multivitamin may still be beneficial.
Today’s Medical News We spoke to Alexandra Fillingieri, M.D., a registered dietitian and physician in clinical nutrition who was not involved in the study, about who should consider taking a daily multivitamin, even if it has no connection to longevity.
“Multivitamins may not be used to prevent disease, but they can help people who aren’t meeting their daily RDAs for micronutrients,” Fillingieri said.
“For example, people with gastrointestinal disorders such as celiac disease or irritable bowel disease may benefit from taking a daily multivitamin supplement,” she noted.
MNT We also spoke with Kiran Campbell, R.D., a heart health specialist at Kiran Campbell Nutrition and medical nutrition advisor at Dietitian Insights, who was not involved in the study.
“Even if taking a daily multivitamin does not extend life expectancy, it may offer benefits, such as preventing nutritional deficiencies, especially in vulnerable populations,” she asserted.
“Multivitamins are beneficial for people age 50 and older,” Campbell said, adding that they can help prevent nutritional deficiencies associated with changes that accompany the normal aging process. “In addition, multivitamin use may help prevent cognitive decline and memory loss that occurs with age.”
Campbell said:
“Most adults are found to be lacking in their intake of fruits, vegetables, legumes, and whole grains. These foods are highly nutritious and provide the vitamins and minerals needed to maintain normal bodily functions and promote healthy aging. While a multivitamin may not be the most accessible way to get these nutrients, for some people it may be the most convenient way.”
Fillingieri added: “[populations] People who are susceptible to micronutrient deficiencies may benefit from daily supplementation.”
“Your doctor or registered dietitian can help you make educated decisions about appropriate supplementation,” she advised.
Campbell stressed that no multivitamin is a substitute for an overall healthy diet.
To maintain health and promote longevity, she recommends focusing on consuming a variety of nutrient-rich foods, rather than relying on supplements, such as:
For inspiration, she said, “look to primarily whole-foods, plant-based eating patterns like the Mediterranean diet or the Blue Zones diet. These eating patterns emphasize cultural, behavioral and social factors, in addition to whole foods, as the answer to lifelong health.”
“The best way to obtain daily nutrition will always be a whole food diet. This is because a diet consisting mainly of whole foods contains fiber, polyphenols and other active compounds that can prevent the development of chronic diseases and maintain adequate health.”
— Kiran Campbell, R.D.
But Campbell noted that in settings where access to fresh produce and high-quality whole foods is limited, the use of multivitamins could help individuals reach adequate nutritional levels. She said multivitamins have several valuable uses and that “socioeconomic factors also need to be considered when assessing the feasibility of providing public health support nationwide.”
After all, “[supplements] “It needs to be individualized to each person’s specific needs,” Fillingieri concluded.
