Experts say that getting your vitamins and minerals from whole foods is better than relying on a pill or powder. That's because researchers still aren't entirely sure how synthetic supplements interact in the body. For example, large doses of folic acid, the synthetic form of folate, have been linked to an increased risk of prostate and colon cancer. Those who get a lot of folate from food sources don't have the same risk. As a result, some manufacturers are focusing on food-based ingredients rather than their synthetic counterparts. New Chapter Organics, Garden of Life and Nature's Way are just a few companies that have multivitamin lines with food-based ingredients.
Liquid and gummy multivitamins for adults generally get good reviews from users who have trouble swallowing pills, but not many of these are included in the latest round of testing. We found no evidence to suggest that liquid multivitamins are more effective than pill-based supplements, and ConsumerReports.org says studies show no difference in absorption rates between liquid and pill multivitamins.
Consider the following when shopping for multivitamins:
Multivitamin ingredients are measured in terms of the daily value (DV). The recommended amount of each vitamin and mineral is established by the FDA and is based in part on the recommended dietary allowances (RDA). To add to the confusion, RDA and DV are used concurrently to describe nutrient recommendations. According to the National Institutes of Health, the RDA is the amount of a nutrient needed to meet the daily basic needs of healthy people. It's one of the factors used to determine daily values, the amounts recommended to help prevent disease that are often higher than the RDA. The DV is presented on food labels and the RDA is mainly used by health professionals.
The newest standard for nutrient requirements is Dietary Reference Intake (DRI). This system was developed by the U.S. National Academy of Sciences' Institute of Medicine in consultation with Health Canada and is used in both countries. DRI recommendations are made up of three components: the estimated average requirements (EAR), a level nutritionists say should meet the needs of 50 percent of the people in a defined age and gender group; the RDA or, where no RDA has been established, the adequate intake (AI); and the upper limit (UL), meaning the highest level that experts consider safe.
Confused? You're not alone. Even among research and nutrition professionals, there's considerable debate about optimal levels and safe upper limits. Part of the problem is that researchers don't yet understand completely how these substances work in the body.
For every study that links a supplement to a supposed health benefit, there's probably another study that links it to adverse health effects. So what's a person to do? Experts agree that getting your nutrients from whole foods is best -- you reap all the benefits of each individual vitamin without the risk of side effects seen when those same vitamins are taken in supplement form. The science on nutritional supplements is constantly evolving, but it's unlikely that a single dietary supplement or vitamin will ever be a silver bullet for our health woes. Your best bet is to ask your doctor whether specific supplements or multivitamins are necessary for your individual health condition.