The report, published in the Journal of the American College of Cardiology, looked at published studies that were done using B vitamins, beta carotene, vitamins A, C and D, calcium, folic acid, selenium and zinc.
The authors were seeking to assess the current state of evidence following the publication in 2012 of the US Preventive Service Task Force review. The report is a meta-analysis and systematic review of other meta-analyses and random controlled trials in the 2012-2017 period.
No CVD benefit found
The authors ended up including 179 studies in their review. They concluded that despite exhaustive study of these nutrients, no lessening of cardiovascular disk risk or reduction of overall mortality could be found for most of the ingredients.
“Of the 4 most commonly used supplements (multivitamins, vitamin D, calcium, and vitamin C), none had a significant effect on cardiovascular outcomes. . . Furthermore, none had an effect on all-cause mortality. . . . [V]itamin D, the most studied nutrient, with 43 RCTs, illustrates the lack of harm or benefit, with 2,908 deaths in 18,719 test subjects and 2,968 deaths in 18,831 control subjects,” they wrote.
The report wasn’t all doom and gloom for the advocates of multivitamin supplementation. The meta-analysis found a moderate reduction in stroke risk associated with B-complex vitamins and a more pronounced effect associated with folic acid.
But the researchers also found a “marginally significant” increase in overall mortality associated with antioxidant mixtures (which the researchers defined as two or more of the following: Vitamins A, C, E, β-carotene, selenium and zinc) and extended release or ‘non flush’ niacin when used by patients also using statin drugs. In the case of niacin, evidence for this finding came from only three trials, however.
Emphasizing the positive
Andrea Wong, PhD, vice president of scientific and regulatory affairs for the Council for Responsible Nutrition said her organization preferred to focus on the positive aspect of the study.
“We want to highlight an exciting outcome of this study which is the data showing folic acid and B-complex vitamins in reducing stroke risk. This is an important finding and should not be ignored,” Wong told NutraIngredients-USA.
“This study also shows that adding to the body of science on nutrients is very important,” she added.
Wong said it is disappointing that negative attention will be focused on the null finding in the study, but she said it does to some extent miss the point. It’s a crude analogy, but multivitamin supplementation is there to make sure all the pieces of the house are in place; it doesn’t claim to prevent it from burning down.
“We have to remember that these supplements provide nutrients. They are not intending to prevent cardiovascular disease so we should not expect the data to show that,” she said.
“There is definitely a need for supplementation. The comments that have come from the publication of this study that Americans can get all the nutrients they need from food is not accurate and is unrealistic. Several of the nutrients included in this analysis have been identified as shortfall nutrients,” Wong added.
NPA: Data backs many health effects of supplements
The Natural Products Association, another industry trade group, also emphasized the importance of multivitamin ingredients in overall health. It’s well documented, NPA said, that Americans fall short in many key nutrients. It should not be extrapolated that from the narrow analysis of this one study that these ingredients have no health benefits at all.
“In an ideal world, everyone would get the nutrients they need by eating a balanced diet, but unfortunately that is not the case,” said Daniel Fabricant, PhD, president and CEO of NPA.
“While there is no magic pill just as there is no one single food providing all of your daily needs, supplementing your diet with nutritional supplements can benefit your healthy lifestyle. The US Food and Drug Administration has supported the use of calcium and vitamin D to help with osteoporosis, the use of folic acid supplements in pregnant women to reduce the risk of neural tube defects, and fatty acid fish oils to reduce the risk of coronary heart disease.”
Source: Journal of the American College of Cardiology
“Supplemental Vitamins and Minerals for CVD Prevention and Treatment”
Volume 71, Issue 22, 5 June 2018, Pages 2570–2584; https://doi.org/10.1016/j.jacc.2018.04.020
Authors: Jenkins DJA, Spence JD, Giovannucci EL, et al.