Is 100% of the Daily Value Really Enough?
If you take a one-a-day multivitamin, or eat a bowl of cereal that provides 100% of the Daily Value for essential vitamins and minerals, are you really meeting your body’s daily nutrient needs for optimal health?
The Daily Value, which is the number you see on Nutrition and Supplement Facts labels, expresses the percentage of the DRI (Dietary Reference Intake) for a given nutrient that you will obtain by consuming a serving of the food or supplement contained in the package. These numbers have formed the basis for a number of marketing campaigns geared towards Americans looking to fill in the gaps in their diet.
But more and more, research suggests that there are profound health benefits associated with consuming certain nutrients, like vitamin D, magnesium and others, in amounts significantly higher than those suggested by the RDA and DRI. So, why the lack of gusto when it comes to exceeding some of these guidelines for increased health benefits?
Many Americans have been made to fear higher nutrient intakes, as a result of alarming and often unclear messages from the FDA and other government agencies. They worry that there is a posed risk of “overdosing” on a nutrient if more than the RDA is consumed. But that’s not always the case.
While these guidelines are effective tools for ensuring that you are meeting your basic nutritional needs, they’re based on the “average” daily nutrient intake level considered to be the bare minimum required to meet the needs of “most people.”
Simply put, these guidelines are designed to merely prevent nutrient deficiencies that are associated with specific conditions. They are not designed to promote vibrant health, ever-increasing wellness and an overall higher quality of life.
For example, the recommended intake for vitamin D is set at 400 IU to prevent rickets, a bone softening condition most common among children in developing countries. Last I checked, we were not a nation in danger of a rickets epidemic. However, we are discovering that due to compromised vitamin D absorption and reduced UV ray exposure, many children and adults have dangerously low vitamin D levels which could lead to osteoporosis and hormonal problems among other things. The future implications for individuals with low vitamin D levels should be of great concern.
Luckily, the current recommendations for vitamin D are under review. When the long-awaited 2010 Dietary Guidelines were released in June, I was happy to read that vitamin D was among the four Specific Underconsumed Nutrients of Public Health Concern. While the Dietary Guidelines Advisory Committee (DGAC) acknowledges the shortcomings of the current recommendations for vitamin D, they chose to hold off on the systematic review at this time since the Institute of Medicine is currently reviewing the DRI for vitamin D.
Another good example is vitamin B12. The RDA for B12 is 2.4 mcg. This recommendation is based on the minimum amount of B12 you need for proper red blood cell formation, DNA synthesis and a number of other cellular functions that require B12 as a cofactor. But there are a number of benefits associated with higher B12 intake such as better cognitive function and a reduced risk of cardiovascular troubles. In fact, due to decreased absorption as we age, many people can benefit from supplementing with 1,000 mcg or more of B12 a day.
Three recent studies, published in the February 23rd issue of Archives of Internal Medicine, focused on the unique roles that some higher-dose nutrients play in preventing certain chronic conditions. The findings of these studies suggest that the procedures used to establish and uphold the Tolerable Upper Intake Level (UL) of certain nutrients may be flawed and outdated.
The Institute of Medicine established the ULs in 1997 with the good intention of raising awareness about the potential risks associated with “mega dosing” for a long period of time without the supervision of a physician or nutritionist. Over time, however, the language used to define the ULs has caused many to limit their intakes of nutrients that have protective properties at higher doses, due to fear that one might overdose or reach a level of toxicity.
The UL system does not yet include a clear distinction between “tolerable” and “safe.” Nor has the Institute of Medicine thoroughly weighed the many advantages against the possible risks of some nutrients taken at higher doses when under the care of a physician. Additionally, the ULs were established without accounting for possible malabsorption. Calcium uptake, for example, can be compromised by many factors such as age, mineral depletion of food sources, low vitamin D levels and poor digestive health. Therefore, it may be necessary for some people to exceed the UL of 2,500 IU to meet their body’s needs.
In 2003, health officials convened to discuss the applications and implications of the ULs, as well as the methodology for establishment. They concluded that the UL system has some serious shortcomings. They agreed that the UL system does not fully account for population subgroups, and in some cases, it contradicts recommendations made by the RDA or DRI. It also does not account for nutrient-nutrient interactions, which can play an important role in the uptake and storage of vitamins and minerals. There are many factors that need to be more closely examined so that the ULs can serve as a better tool for promoting health and well-being.
“There is an increasing body of science, which these new papers in Archives of Internal Medicine support, that shows high doses of supplements are both safe and effective. To get some perspective on it, the levels found to be most beneficial in preventing macular degeneration were over twelve times the U.S.’s Recommended Daily Allowance (RDA) of folate, twenty-five times the RDA of vitamin B6, and 1000 times the RDA of vitamin B12,” says Dr. Robert Verkerk, Scientific Director of the Alliance for Natural Health USA said in a press release.
These studies, along with others that indicate there are many advantages associated with supplementing with nutrients in doses beyond the DRI, RDA and UL, opens the door for researchers, doctors and nutritionists to re-examine the current guidelines. Perhaps these studies will help to establish a new list of guidelines which more clearly defines the nutrient doses that have clinically proven to be useful for preventing many chronic diseases that threaten us as we age.
Many of these findings simply support the fact that there is no “one size fits all” when it comes to nutrient intake. What is sufficient for one may be too little for another. The current guidelines and ULs are designed to meet the requirements of the mythical “average person.” When you are designing your nutritional regimen, there are many factors to consider, and you should understand that your needs may not be met by the nutrient recommendations given by the traditional guidelines.
Arch Intern Med. Vol. 169 No.4, pp. 328-418, Feb. 23, 2009.