The meta-analysis found that folic acid and B vitamins have only minimal protective benefits for cardiovascular disease and stroke, respectively.
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Dietary supplement industry associations are pushing back on negative conclusions drawn from a new meta-analysis1 on efficacy of vitamins and minerals for preventing cardiovascular disease. The meta-analysis, published in Journal of the American College of Cardiology and titled “Supplemental Vitamins and Minerals for CVD Prevention and Treatment,” found that folic acid and B vitamins have only minimal protective benefits for cardiovascular disease and stroke, respectively. More negatively, the meta-analysis concluded that multivitamins, vitamin C, vitamin D, β-carotene, calcium, and selenium have no effect on cardiovascular events; and that antioxidant mixtures (a combination of two or more of the following: vitamins A, C, E, β-carotene, selenium, zinc), and niacin with a statin, actually increased the risk of all-cause mortality.
The current meta-analysis included individual randomized, controlled trials from previous meta-analyses and systematic reviews on cardiovascular disease outcomes, published between January 2012 and October 2017. Notably, the researchers included studies published both before and after an Annals of Internal Medicine review was published in 2013, by the U.S. Preventive Service Task Force, on vitamin and mineral supplements for the prevention of cardiovascular disease and cancer.2 The U.S. Preventive Services Task Force is an independent, volunteer panel of experts in disease prevention and evidence-based medicine.
Researchers of the current Journal of the American College of Cardiology meta-analysis concluded that there was no evidence to support the benefits of dietary supplements for preventing cardiovascular events, and that, therefore, “any benefits seen must be balanced against possible risks.”
On one somewhat positive note, the authors found that in several of the meta-analyses they examined, B-complex vitamins and folic acid did help to reduce the risk of stroke. Folic acid likewise reduced the risk of cardiovascular disease in five of the meta-analyses consulted in the current study.
Much of the subsequent media attention on this meta-analysis concluded that dietary supplements are not effective in preventing cardiovascular disease. In response to the study, Duffy MacKay, ND, senior vice president, scientific and regulatory affairs, Council for Responsible Nutrition (CRN; Washington, DC), said that dietary supplements are not geared toward disease prevention but rather for supporting overall health and that this study gives consumers the erroneous impression the supplements do not exert any heart-health benefits.
MacKay explained in a press release from CRN that “the most significant finding in this review is the beneficial role vitamin B-complex and folic acid can play in reducing the risk of stroke. Stroke is one of the leading killers in America, and thus we should feel nothing but enthusiasm for this new review which presents significant promise for advancements in the risk reduction of cardiovascular disease.”
He continued: “Given these positive findings, we are disappointed by the negative attention being given toward the most popular supplements because the research found they do not prevent cardiovascular disease. The multivitamin as well as vitamins D and C are equally beneficial for overall health and wellness. They are not intended for cardiovascular disease prevention, so we shouldn’t expect the data to demonstrate otherwise.”
MacKay added that consumers should be aware that cardiovascular disease “is multifactorial and cannot be prevented by dietary supplements in isolation.” CRN recommends that any consumer who has, or is at risk of, cardiovascular disease should consult his or her doctor for medical treatment. “However,” he noted, “we in the scientific and medical communities should not disregard new science that suggests the use of specific dietary supplements in combination with healthy diet and exercise could ultimately lead to improved quality of life for consumers as well as healthcare cost savings to individuals and the country.”
Both MacKay and Daniel Fabricant, president, CEO, Natural Products Association (NPA; Washington, DC), pointed out that most Americans do not obtain the daily recommended nutrients from their diets alone. Supplements can help make up some of the difference, and thus, can help to reduce the risk of adverse cardiovascular events or stroke. According to Fabricant, as many as 80% of Americans do not meet their daily nutrient requirements, while more than 50% of children don’t get enough vitamin D and vitamin E. Finally, over 25% of American children don’t get enough calcium, magnesium, or vitamin A.
“In an ideal world, everyone would get the nutrients they need by eating a balanced diet, but unfortunately that is not the case,” said Fabricant. “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 U.S. 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.”
Added MacKay: “There is a real life need for dietary supplements, and the argument that Americans get all the nutrients they need from food alone is inaccurate. As indicated in the 2015 Dietary Guidelines, vitamins D and C, along with many other nutrients you’ll find in a multivitamin, are identified as shortfall nutrients. To dismiss their benefit is to do a great disservice to the American populations who are not getting enough of these critical nutrients from their diets.”
1. Jenkins DJA et al., “Supplemental vitamins and minerals for CVD prevention and treatment,” Journal of the American College of Cardiology, vol. 71, no. 5 (June 2018): 2570-2584
2. Fortmann SP et al., “Vitamin and mineral supplements in the primary prevention of cardiovascular disease and cancer: an updated systematic evidence review for the U.S. Preventive Services Task Force,” Annals of Internal Medicine, vol. 159 (December 2013): 824–834