Multivitamin Supplements are Safe and Nutritious
Two trials found a small, borderline-significant benefit from multivitamin supplements on cancer in men only and no effect on CVD. So reads the conclusion by Fortmann and colleagues after systematically reviewing studies on multivitamin use by community-dwelling, nutrient-sufficient adults. What does this mean? What about women?
Cancer and cardiovascular disease are complex non-communicable diseases. Prevalence is attributable to many environmental and lifestyle influencers, including multiple nutrients – amount and type of fat consumed, vitamins, alcohol intake, etc. Using studies primarily conducted in men (because there weren’t many involving women), the most promising results came from 2 multivitamin trials using a wide variety of nutrients at physiological doses.
Even in people with overt (or very high risk) of a nutrient deficiency, health outcomes are more likely to be improved when multiple nutrients are provided (versus only the deficient nutrient). The reason is simple. Multiple nutrient gaps usually exist even when one nutrient is most limiting. Thus multivitamin supplements are more likely to fulfill nutrient needs and affect health in undernourished persons. The same logic applies to better nourished people.
It is expensive and time consuming to recruit volunteers to intervention studies. Volunteers for clinical trials are not average. Volunteers are often in better physical health than the rest of the population, i.e. their peers. According to research by Kim and Ferraro, C-reactive protein (CRP) levels, a biomarker of inflammation and stress, can be 15% lower in volunteers than those who don’t. Participants in the Physicians’ Health Study II were much healthier than those who didn’t opt in (Sesso et al, 2002). Statistics from intervention trials may not be fully applicable to those who haven't taken the initiative to volunteer for a nutrition study (the majority).
The statement by Duffy MacKay, vice president of scientific and regulatory affairs at the Council for Responsible Nutrition (CRN), summarizes the evidence well. Cancer is complex. The evidence that well-nourished individuals using supplements to achieve higher intakes of vitamins and minerals will have less risk of cancer is limited but multivitamin supplements are safe. Here are some other facts to consider.
Nutrients work together. Vitamins and minerals are essential to maintain healthy, functioning cells. Most of the time our plate doesn’t look like the recommended MyPlate. We don’t have the recommended number of servings from all the food groups. Multivitamin supplements are a valuable source of vitamins and minerals needed by your body. Be confident and secure in your knowledge that multivitamin supplements are safe and can help ensure nutrient adequacy.
Fortmann SP, Burda BU, Senger CA, Lin JS, Whitlock EP. Prevention of cardiovascular disease and cancer: An updated systematic evidence review for the US Preventive Services Task Force. 2013 Ann Inter Med doi:10.7236/0003-4819-159-12-201312170-00729
Kim S, Ferraro KF. Do productive activities reduce inflammation in later life? Multiple roles, frequency of activities, and c-reactive protein. 2013 The Gerontologist doi:10.1093/geront/gnt090
Sesso HD, Gaziano JM, VanDenburgh M, Hennekens CH, Glynn RJ, Buring JE. Comparison of baseline characteristics and mortality experience of participants and nonparticipants in a randomized clinical trial: the Physicians’ Health Study. 2002 Control Clin Trial 23:686-702