Are multivitamins (multiple vitamins) effective?

From the Guidelines

Multivitamins are not effective in preventing chronic diseases or extending lifespan for most healthy adults, and their use is not recommended for primary prevention of cardiovascular disease and cancer. The U.S. Preventive Services Task Force (USPSTF) has concluded that the evidence is insufficient to recommend for or against multivitamins for the prevention of cardiovascular disease or cancer 1. This recommendation is consistent with other organizations, such as the American Cancer Society, the American Heart Association, and the Academy of Nutrition and Dietetics, which all recommend a balanced diet with a variety of foods rather than supplements for healthy individuals.

Some key points to consider:

• The USPSTF found that new evidence on vitamin E increased their certainty about its lack of effectiveness in preventing cardiovascular disease and cancer 1.
• The Academy of Nutrition and Dietetics noted that while multivitamin supplements may be useful in meeting recommended levels of some nutrients, there is no evidence that they are effective in preventing chronic disease 1.
• Certain populations, such as pregnant women, older adults, and vegans, may benefit from specific supplements, but this should be determined on an individual basis with the guidance of a healthcare provider.
• A healthy diet rich in fruits, vegetables, whole grains, lean proteins, and healthy fats can provide sufficient nutrients for most people, making multivitamins unnecessary.

In terms of specific recommendations, the American Heart Association and the American Academy of Family Physicians advise healthy individuals to receive adequate nutrients through a balanced diet rather than supplementation 1. The most effective approach to maintaining good health is to focus on a balanced diet and a healthy lifestyle, rather than relying on multivitamins or other supplements. If you're considering taking a multivitamin, it's best to consult with a healthcare provider who can assess your individual needs and provide personalized guidance.

From the Research

Effectiveness of Multivitamins

• The evidence on the effectiveness of multivitamins in preventing chronic diseases is mixed and insufficient to prove their benefits 2, 3, 4, 5.
• Some studies suggest that multivitamins may have benefits in specific populations, such as:
  • Reducing the incidence of gastric cancer and mortality in poorly nourished Chinese populations 2, 5.
  • Reducing the rate of cancer in men, but not women, in a French trial 2, 5.
  • Slowing the progression of advanced age-related macular degeneration in high-risk individuals 2, 5.
• However, other studies have found no significant benefits of multivitamins in preventing:
  • Cardiovascular disease 2, 3, 5.
  • Cataracts 2, 5.
  • Chronic diseases in the general population 3, 4, 5.

Safety of Multivitamins

• The safety of multivitamins has been evaluated in several studies, with most finding no consistent adverse effects 2, 3, 5.
• However, some studies have raised concerns about the potential risks of:
  • Exceeding upper levels of recommended intakes 4.
  • Interactions with other medications or health conditions 6.
• Long-term use of multivitamins within recommended intakes has been determined to be safe in healthy adults 3.

Recommendations

• The use of multivitamins should be individualized based on age, sex, life cycle, and other characteristics 3.
• Multivitamins may be beneficial for individuals with inadequate micronutrient intake or biomarker status 3.
• However, the evidence is insufficient to recommend multivitamins for the primary prevention of chronic diseases in the general population 2, 3, 4, 5.