Despite Popularity Of Dietary Supplements, Little Evidence They Help: JAMA

The average person does not benefit from taking vitamins and dietary supplements, according to a new research editorial. 

In findings published this week in the Journal of the American Medical Association (JAMA), researchers indicate that the majority of clinical trials provide no evidence that vitamins or dietary supplements offer benefits above and beyond what they get from simply eating a diet rich in nutrient dense foods.

The dietary supplement industry generates more than $30 billion in the United States, with more than 90,000 products on the market. Yet, most consumers are unaware of the fact that the FDA does not regulate the safety and efficacy of supplements and vitamins, often incorrectly assuming that the agency provides the same regulatory oversight that it does for medications.

The editorial indicates that more than 52% of U.S. adults use at least one supplement and about 10% of adults use four different supplements.

Research indicates vitamins and minerals are the most popular dietary supplements. Nearly half of adults in the U.S. take vitamins and about 40% take minerals. Most users take vitamins and dietary supplements to help maintain their health or prevent illness or disease.

Authors of the study emphasized the majority of clinical trials focusing on vitamin and dietary supplements do not demonstrate the ability to prevent disease, which is unrelated to nutritional deficiency.

Researchers also emphasized some studies suggest high doses of some micronutrients may have harmful effects, such as increased rates of mortality, cancer, and hemorrhagic stroke.

Doctors JoAnn E. Manson and Shari S. Bassuk, of Harvard, indicate that doctors should warn patients dietary supplements and vitamins are not a good substitute for a healthy, nutrient dense, well-balanced diet. Patients should know, in most cases, taking dietary supplements offer little benefit.

Doctors should also highlight the advantages of getting their vitamins and minerals from food instead of supplements.

Research has shown micronutrients gained from food sources are better absorbed by the body than synthetic dietary supplements. It is also associated with fewer potential side effects. Researchers warn routine micronutrient supplementation is not recommended for the general population.

However, in some cases, among certain high risk groups or populations, dietary supplementation may be necessary.

For example, pregnant women should take folic acid supplements to help prevent neural tube defects in their unborn child. Folic acid is one of few micronutrients which is more bioavailable in synthetic forms than in naturally occurring dietary forms.

Similarly, health officials recommend breastfed infants take vitamin D supplements soon after birth and continue until weaning to vitamin D milk. Adults over the age of 50 are recommended to take vitamin B12, as it is not adequately absorbed by the body after middle age.

Researchers warn doctors should ask patients about vitamin and supplement use and counsel them about interactions with any medications. They should also advise them which supplements may be necessary, and which are not.

Doctors should also make sure patients know dietary supplements are not reviewed or approved by the FDA for safety and efficacy. Thus, patients are taking most vitamins and supplements at their own risk.