For over 50 years we've been led to believe that RDA levels are adequate...
...but adequate for what? Adequate to prevent clinically obvious nutritional deficiencies like scurvy, beriberi, rickets, and pellagra?
According to the Food and Nutrition Board (under the umbrella of the National Institutes of Health): "The Recommended Dietary Allowance (RDA) is the average daily dietary intake level that is sufficient to meet the requirement of nearly all apparently healthy individuals in a particular life stage and gender group." The Food and Nutrition Board further defines "requirement" as: "the lowest continuing intake level of a nutrient that, for a specified indicator of adequacy, will maintain a defined level of nutriture in an individual."
Basically, the RDA is - by their own definition - the lowest level of nutrient intakes that will prevent deficiencies in apparently healthy individuals. And, while RDA levels may have helped us to avoid acute deficiency diseases, they do not address any issues of optimal nutrition.
The RDAs have certainly played an important role in public health. Most assuredly, they provide amounts that will prevent you from getting scurvy, pellagra, rickets or beriberi. However, in the general population, these vitamin-related diseases are of little concern. Products based solely on RDA amounts are fine for their intended purpose (i.e. providing minimal amounts of important vitamins and minerals), but the RDA of vitamins and minerals is not always enough to help prevent certain degenerative diseases or to provide protection from oxidative damage.
In other words, there are more benefits of nutritional supplementation than just preventing rare deficiencies. Really, the RDA should only be considered the "minimum wage" of nutrition.
USANA's products are formulated with the most up-to-date nutritional research in mind, which may or may not have relevance to the RDAs. Rather than just trying to prevent total vitamin deficiencies, we are concerned with the vast majority of people who are "apparently" healthy. Many degenerative diseases and chronic illnesses develop over a lifetime, striking otherwise healthy individuals when they least expect it.
The bottom line is that for the millions of "apparently" healthy individuals in the world, minimal nutrient intakes and the RDAs are not always adequate - or even designed - to address our most common health challenges.
USANA's nutritional supplements are designed to complement a healthy diet - not replace it. Our supplements are designed to provide advanced levels of vitamins, minerals, and antioxidants that are difficult to obtain from diet alone; levels that we could all use, everyday, to promote a lifetime of good health.
More importantly, we are not the only ones who are convinced of the health benefits of nutritional supplements. In June 2002, the Journal of the American Medical Association published two articles by health researchers at Harvard University. Their articles were entitled "Vitamins for Chronic Disease Prevention in Adults". Through their research, these authors concluded that "suboptimal intake of some vitamins, above levels causing classic vitamin deficiency, is a risk factor for chronic diseases and common in the general population, especially the elderly. Suboptimal folic acid levels, along with suboptimal levels of vitamins B6 and B12, are a risk factor for cardiovascular disease, neural tube defects, and colon and breast cancer; low levels of vitamin D contribute to osteopenia and fractures; and low levels of the antioxidant vitamins (vitamins A, E and C) may increase risk for several chronic diseases."
A good source of information on general vitamin and mineral safety is "Vitamin and Mineral Safety, 2nd Edition" by John N. Hathcock, Ph.D. Council of Responsible Nutrition. 2004. Or, you can contact the Council for Responsible Nutrition directly at http://www.crnusa.org/
Yours in health,
D.