Recommended dietary allowances (RDAs) of nutrients?
Originally Published: October 15, 1999 - Last Updated / Reviewed On: August 4, 2009
I've searched your site (and others as well) — I am looking for a listing of the US RDA for all vitamins and minerals in one place all together. I am looking for a vitamin supplement and want to get one that is as complete as possible and want to be able to make comparisons of products available. Thank you so much for your help.
RDAs (Recommended Dietary Allowances), prepared by the Food and Nutrition Board of the National Academy of Sciences, have been around for over 50 years, with periodic updates. The RDA is the average daily dietary intake level that would adequately meet the nutritional needs of nearly all (98 percent) healthy persons. RDAs include nutrients for which there is sufficient scientific evidence that they are required for good health. Their intention has always been to establish "standards to serve as a goal for good nutrition." RDAs provide the basis for evaluating the adequacy of diets of population groups. They are set at a level that includes a safety factor appropriate to each nutrient; so, this level actually exceeds the requirement for most individuals.
The Food and Nutrition Board has established Dietary Reference Intakes (DRIs). In addition to RDAs, DRIs include recommendations for food components for which RDAs cannot be established. Some of these include fat, carbohydrate, fiber, and plant estrogens, among others. DRIs also include maximum intake levels. Three dietary intake reference values for DRIs are:
- Adequate Intake — the dietary intake level that would adequately sustain health when an RDA cannot be determined because of insufficient scientific evidence.
- Estimated Average Requirement — the estimated dietary intake level that would maintain the health of half of a specified age and sex group.
- Tolerable Upper Intake Level — the maximum level of daily nutrient intake that's apparently safe and unlikely to cause negative health effects in most healthy individuals.
DRIs and RDAs are not developed for specific individuals, but are for the making of policies for feeding programs, food labeling, and food fortification. The numbers signify levels of each compound that are appropriate for most healthy people in each category. To access information on RDAs and DRIs, check out the Dietary Guidelines for Americans at the Food and Nutrition Information Center (FNIC) web site of the U.S. Department of Agriculture (USDA).
Vitamin supplements may contain an amount equivalent to the RDA for DRI, but you'll probably not find a supplement with every imaginable nutrient, vitamin, and mineral. There are innumerable substances that keep us healthy, many of which cannot be packaged in a pill. In addition, many nutrients are difficult for the body to absorb when they come in pill form. Obtaining nutrients directly from a balanced diet of fruits, vegetables, whole grains, and lean proteins is still the recommended manner of giving your body all it needs to be healthy.
To assess whether your current diet is filled with nutrients, check out some of the nutritional tools provided by the USDA. You can also speak with your health care provider about whether you need a multivitamin or if the food you eat is sufficient. Take care,