‘Vast Majority’ of Vitamin Supplements Don’t Work, Says Study
In a massive new analysis of findings from 277 clinical trials using 24 different interventions, Johns Hopkins Medicine researchers say they have found that almost all vitamin, mineral and other nutrient supplements or diets cannot be linked to longer life or protection from heart disease.
Although they found that most of the supplements or diets were not associated with any harm, the analysis showed possible health benefits only from a low-salt diet, omega-3 fatty acid supplements and possibly folic acid supplements for some people.
Researchers also found that supplements combining calcium and vitamin D may in fact be linked to a slightly increased stroke risk.
“The panacea or magic bullet that people keep searching for in dietary supplements isn’t there,” said senior author of the study Erin D. Michos, M.D., M.H.S., associate professor of medicine at the Johns Hopkins University School of Medicine.
He added: “People should focus on getting their nutrients from a heart-healthy diet, because the data increasingly show that the majority of healthy adults don’t need to take supplements.”
The vitamin and other supplements reviewed included: antioxidants, ?-carotene, vitamin B-complex, multivitamins, selenium, vitamin A, vitamin B3/niacin, vitamin B6, vitamin C, vitamin E, vitamin D alone, calcium alone, calcium and vitamin D together, folic acid, iron and omega-3 fatty acid (fish oil).
The diets reviewed were a Mediterranean diet, a reduced saturated fat (less fats from meat and dairy) diet, modified dietary fat intake (less saturated fat or replacing calories with more unsaturated fats or carbohydrates), a reduced fat diet, a reduced salt diet in healthy people and those with high blood pressure, increased alpha-linolenic acid (ALA) diet (nuts, seeds and vegetable oils), and increased omega-6 fatty acid diet (nuts, seeds and vegetable oils).
Each intervention was also ranked by the strength of the evidence as high, moderate, low or very low-risk impact.
The majority of the supplements including multivitamins, selenium, vitamin A, vitamin B6, vitamin C, vitamin E, vitamin D alone, calcium alone and iron showed no link to increased or decreased risk of death or heart health.
The authors received no financial support for this research study and declared no conflicts of interest.