There have been only 2 randomized clinical trials addressing whether or not vitamin and mineral supplements are effective for the prevention of cardiovascular disease. One of these, the Physicians’ Health Study II did not find an association between the use of a multivitamin-mineral (MVM) supplement and cardiovascular disease (CVD) in either incidence or mortality after an average of 11 years, in male U S physicians 50 years or older. The other study, the French Supplementation en Vitamines et Mineraux Antioxydants, randomly assigned women and men (women 35-60 y.o.; men 45-60 y.o.) to receive either the daily antioxidant combination (not an MVM – vitamin C, alpha tocopherol, beta carotene, selenium and zinc) or placebo and after 7.5 years CVD incidence was not statistically different between the two arms. In 2010, a large Swedish cohort study of women found that multi vitamins,(MV) without minerals, were associated with a reduced risk of myocardial infarction, and if they used them greater than 5 years, the association was even stronger.
The current study set out to examine the association between MVN and MV use and CVD mortality in US adults who did not previously have CVD. The researchers linked the NHANES II data and the 2011 National Death Index to examine the association between MVM and MV use and mortality due to CVD. These two large surveys provide data on over 10,000 adults 40 years and older. Data points included history of myocardial infarction, stroke, coronary heart disease, cardiovascular disease, non skin cancers, diabetes, alcohol, smoking, height, weight, blood pressure, cholesterol, triglyceride, glucose/glycolated hemoglobin testing, age, race, education, dietary supplements (vitamins, minerals, herbs) , and over the counter and prescription medications. A MVM was defined as 3 or more vitamins and at least 1 mineral. A MV was a vitamin combination without minerals. There were also 3 duration categories of < 1 year, 1-3 years and > 3 years.
Approximately 45% of the individuals evaluated had used a dietary supplement in the previous 30 days. MVMs were the most frequently used (21%) and MVs 14 %.
Results: Neither MVM nor MV use was associated with a lower risk of CVD mortality when they compared users with nonusers. However, when they looked at the length of time of use, there was indeed a significant inverse association for MVM use of > 3 years with a more than 35% reduced risk of CVD mortality in women, but not men. MV only, was not significantly associated with CVD mortality when combining men and women, although men only who had used MV for 1-3 years did have reduced CVD related mortality.
Commentary: It’s reassuring to see some positive data for MVM users and prescribers, and useful to see that longer use, in this case > 3 years is clearly associated with reduced mortality from cardiovascular disease. All kinds of critiques can be lodged against this kind of study, since it is not the gold standard randomized controlled trial. However, even RCT can be criticized because they are often of short duration and have a more homogeneous population of individuals being studied. The current study is strong in the robust diversity of individuals as well as a large sample that were older than 65, which is especially useful when looking at cardiovascular disease mortality.
There are many research studies on individual minerals, vitamins, amino acids, fish oils and herbs that show efficacy in both prevention and intervention in different areas of cardiovascular disease. Examples include magnesium intake and an inverse association with risk of strokes, reduced risk of ischemic heart disease and CVD mortality; protective CV effect of vitamin D; Hawthorne to improve outcomes of congestive heart failure; the many and diverse cardiovascular benefits in prevention and treatment for fish oils (strokes, CVD mortality, blood pressure, type 2 diabetes and more).
As a result of the current study, I will be more eager to recommend long term use of MVM for women in my practice and in my teachings.
Bailey R, Fakhouri T, Park Y, et al. Multivitamin-mineral use is associated with reduced risk of cardiovascular disease mortality among women in the United States. J Nutrition 2015 doi:10,3945/jn.114.204743