Multivitamins Don't Prevent Heart Disease, Stroke

— Meta-analysis "conclusively showing null effects" of supplements

Last Updated July 13, 2018
MedicalToday

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Multivitamin and mineral supplementation neither hurts nor helps cardiovascular health, a meta-analysis showed.

In particular, these supplements showed no effect on:

  • Cardiovascular mortality: RR 1.00 (95% CI 0.97 to 1.04)
  • Coronary heart disease mortality: RR 1.02 (95% CI 0.92 to 1.13)
  • Stroke mortality: RR 0.95 (95% CI 0.82 to 1.09)
  • Stroke incidence: RR 0.98 (95% CI 0.91 to 1.05)

The lack of benefit was observed across subgroups and adjusted analyses, Joonseok Kim, MD, of the University of Alabama at Birmingham, and colleagues reported in the July issue of .

Taking vitamins and minerals was associated with lower risk of coronary heart disease incidence (RR 0.88, 95% CI 0.79 to 0.97), though randomized data alone did not support this.

"We undertook this analysis because, despite numerous studies strongly suggesting the neutral effect of MVM [multivitamin/mineral] supplements on CVD prevention, the controversy did not end, and the scientific community continued to send a confusing signal to the public," Kim's group said.

"Our findings will hopefully serve to dampen the widespread public enthusiasm for MVM use by conclusively showing null effects."

The meta-analysis included 18 studies published in 1970-2016 (11 from the U.S., four from Europe, and three from Japan) with a total of more than 2 million participants from the general population.

The investigators cautioned that many of the included studies relied on self-reported supplement use and that their pooled analysis likely inherited other limitations, such as residual confounding factors.

It is "logical" to expect certain vitamins to reduce cardiovascular events, given their anti-inflammatory effects, Alyson Haslam, PhD, and Vinay Prasad, MD, MPH, both of Oregon Health & Science University in Portland, noted in an .

Yet the findings by Kim's group "may not ultimately be surprising in 2018," they said.

"Preventing or treating disease with vitamin supplements was relatively simple when foods were limited, frank vitamin deficiency was possible, and common diseases had a clear etiology, such as vitamin C deficiency for scurvy or thiamine deficiency for beriberi. Now that diets are more varied, supplemented, and fortified, diseases of frank vitamin deficiency are rare, and the most commonly occurring diseases have a multifactorial etiology," Haslam and Prasad continued.

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    Nicole Lou is a reporter for , where she covers cardiology news and other developments in medicine.

Disclosures

Kim and Haslam disclosed no relevant conflicts of interest.

Prasad reports receiving royalties from his book Ending Medical Reversal; that his work is funded by the Laura and John Arnold Foundation; that he has received honoraria for Grand Rounds/lectures from several universities, medical centers, and professional societies; and payments for contributions to Medscape.

Primary Source

Circulation: Cardiovascular Quality and Outcomes

Kim J, et al "Association of multivitamin and mineral supplementation and risk of cardiovascular disease: A systematic review and meta-analysis" Circ Cardiovasc Qual Outcomes 2018; DOI: 10.1161/CIRCOUTCOMES.117.004224.

Secondary Source

Circulation: Cardiovascular Quality and Outcomes

Haslam A, Prasad V "Multivitamins do not reduce cardiovascular disease and mortality, and should not be taken for this purpose: How do we know that?" Circ Cardiovasc Qual Outcomes 2018; DOI: 10.1161/CIRCOUTOMES.117.004886.