Dietary supplements demonstrate no mortality benefits
While adequate intake of certain nutrients derived from food was associated with lower all-cause mortality, nutrients derived from supplements were not, according to findings published in Annals of Internal Medicine.
“More than half of American adults use dietary supplements and among them, half take dietary supplements on their own without consulting their doctors,” Fang Fang Zhang, MD, PhD, from the Friedman School of Nutrition Science and Policy at Tufts University, told Healio Primary Care Today. “It remains controversial whether dietary supplement use is associated with health benefits or risks. The effect of dietary supplement use on health needs further evaluation.”
Zhang and colleagues evaluated data from the 1999 to 2010 National Health and Nutrition Examination Survey (NHANES) and National Death Index to determine how dietary supplement use and levels of nutrient intake from foods affect all-cause, CVD and cancer mortality among adults in the U.S. aged 20 years or older (n = 30,899).
Participants reported on their nutrient intake from foods and supplements and whether they had used a dietary supplement in the previous 30 days. They were followed for a median of 6.1 years.
Approximately half (51.2%) of participants used dietary supplements, mainly multivitamin and mineral supplements (38.3%), within the past 30 days. Vitamin C (40.3%), vitamin E (38.6%) and vitamin D (37.6%) were the most commonly used vitamin supplements. Calcium (38.6%), zinc (34.5%) and magnesium (33.3%) were the most commonly used mineral supplements.
The researchers identified 3,613 deaths, including 945 CVD deaths and 805 cancer deaths, over the course of the study.
There was no association between ever-use of dietary supplements and mortality outcomes. Participants with adequate intake of vitamin A, vitamin K, magnesium, zinc and copper via foods, not supplements, had lower rates of all-cause and CVD mortality.
Participants who consumed excess amounts of calcium, defined as more than 1,000 mg per day, demonstrated a higher risk for cancer-related deaths. This association appeared to be greater when the nutrient came from a supplement.
In individuals with low nutrient intake from food, dietary supplements still did not affect the risk of death, according to the researchers.
Participants with no apparent vitamin D deficiency who used vitamin D supplements had a higher risk of all-cause death.
“It is important to improve the communications on dietary supplement use between providers and patients,” Zhang said. “Clinicians play important roles in advising patients for nutrition and dietary supplement use. Clinicians can tell patients that regular use of dietary supplement is not recommended for the general population in the United States.”
“Further investigations are needed to evaluate whether certain subgroups may benefit from dietary supplement use, and yet it is clear that dietary supplement use should not be considered as a substitute for a healthy balanced diet,” she added.
“The general U.S. population should aim for achieving adequate nutrition through a healthy and balanced diet rather than counting on dietary supplements,” she continued. “For certain subgroups such as individuals with medical conditions that lead to malabsorption of nutrients from foods or those who have specific dietary practices that could cause nutritional deficiency, their nutritional needs including the use of dietary supplements shall be evaluated separately.” – by Alaina Tedesco
Disclosures: Chen reports no relevant financial disclosures. Please see study for all other authors’ relevant financial disclosures.