NEW YORK, June 29: New research analyzing data from over two decades and nearly 400,000 participants in the United States suggests that long-term daily multivitamin use may not improve longevity in healthy adults.

Approximately 33% of U.S. adults take a daily multivitamin, assuming it may help prevent disease and contribute to a longer, healthier life. Despite widespread use, previous studies have not found sufficient evidence to determine whether multivitamins actually benefit longevity.

Researchers at the National Institutes of Health’s (NIH) National Cancer Institute aimed to address this gap by analyzing long-term daily multivitamin use and mortality risk in three cohorts of healthy U.S. adults. They accounted for factors such as diet, lifestyle, and reverse causation, where individuals in poor health started using multivitamins.

Their pooled analysis included data from three large cohort studies: the NIH-AARP Diet and Health Study, the PLCO Cancer Screening Trial, and the Agricultural Health Study, totaling 390,124 healthy adult participants aged 18 to 74 with no history of major chronic diseases.

Participants self-reported their frequency of multivitamin use, and the researchers categorized them into three groups: no multivitamin use, non-daily use, and daily use. Other factors considered included diet history, smoking status, alcohol and coffee intake, race and ethnicity, education level, body mass index (BMI), physical activity level, and family history of cancer.

Over the study period, there were 164,762 recorded deaths, with approximately 30% due to cancer, 21% to heart diseases, and 6% to cerebrovascular diseases. Among daily multivitamin users, nearly half were female, compared to about 40% of nonusers. Daily users were also more likely to use other supplements, have a lower BMI, and better diet quality.

Despite these differences, the analysis found no significant difference in survival between multivitamin users and non-users for overall mortality and specific causes like heart disease, cancer, and cerebrovascular disease. In fact, daily users had a 4% higher risk of death, although the hazard ratio values suggested no difference in survival between the groups.

The study authors note that while multivitamins may not extend longevity, they may still be associated with other important outcomes related to healthy aging, such as supporting cognitive function in older adults. The research has limitations, including its observational nature, which cannot establish cause and effect, and potential unaccounted factors like healthcare utilization.

Healthy adults with adequate dietary nutrient intake might not benefit from multivitamin use, but specific populations might. Alexandra Filingeri, a registered dietitian, mentioned that populations with gastrointestinal conditions, like celiac disease, may benefit from daily multivitamin supplementation. Kiran Campbell, a dietitian specializing in heart health, emphasized that while daily multivitamins may not prolong life, they can prevent nutrient deficiencies in vulnerable populations and support aging adults over 50.

Both experts agree that no multivitamin can substitute for an overall healthy diet. They recommend focusing on consuming a variety of nutrient-dense foods, such as nuts, seeds, legumes, dark leafy greens, carrots, berries, and other colorful plant-based foods. Dietary patterns like the Mediterranean diet or the Blue Zone diet, which emphasize whole foods, can promote lifelong health.

In cases where access to fresh produce is limited, multivitamin use may help individuals reach adequate nutrient levels. Socioeconomic factors must also be considered when assessing public health feasibility.

Ultimately, supplements should be individualized to each person’s specific needs, and medical professionals can help determine proper supplementation.