Dietary reference intake

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

The Dietary Reference Intake is a system of nutrition recommendations from the Institute of Medicine of the USA National Academy (IOM). The DRI system is used by both the United States and Canada. It is intended for the general public and health professionals. Applications include:

• Food labels in the United States and Canada
• Composition of diets for schools, prisons, hospitals or nursing homes
• Industries developing new food stuffs
• Healthcare policy makers and public health officials

In 1997, at the suggestion of the Institute of Medicine of the National Academy, the RDA became one part of a broader, more detailed set of dietary guidelines, called the Dietary Reference Intake.

History

The Recommended Dietary Allowance (RDA) was developed during World War II by Lydia J. Roberts, Hazel K. Stiebeling and Helen S. Mitchell, all part of a committee established by the U.S. National Academy of Sciences in order to investigate issues of nutrition that might "affect national defense" (Nestle, 35). The committee was renamed the Food and Nutrition Board in 1941, after which they began to deliberate on a set of recommendations of a standard daily allowance for each type of nutrient. The standards would be used for nutrition recommendations for the armed forces, for civilians, and for overseas population who might need food relief. Roberts, Stiebeling, and Mitchell surveyed all available data, created a tentative set of allowances for "energy and eight nutrients", and submitted them to experts for review (Nestle, 35). The final set of guidelines, called RDAs for Recommended Dietary Allowances, were accepted in 1941. The allowances were meant to provide superior nutrition for civilians and military personnel, so they included a "margin of safety." Because of food rationing during the war, the food guides created by government agencies to direct citizens' nutritional intake also took food availability into account.

The Food and Nutrition Board subsequently revised the RDAs every five to ten years. In the early 1950s, USDA nutritionists made a new set of guidelines that also included the number of servings of each food group in order to make it easier for people to receive their RDAs of each nutrient.

Current recommendations

The current Dietary Reference Intake recommendation is composed of:

• Estimated Average Requirements (EAR), expected to satisfy the needs of 50% of the people in that age group.
• Reference Daily Intake (RDI), the daily dietary intake level of a nutrient considered sufficient to meet the requirements of nearly all (97–98%) healthy individuals in each life-stage and gender group.
• Adequate Intake (AI), where no RDI has been established, but the amount established is somewhat less firmly believed to be adequate for everyone in the demographic group.
• Tolerable upper intake levels (UL), to caution against excessive intake of nutrients (like vitamin D) that can be harmful in large amounts.

The RDI is used to determine the Recommended Daily Value (RDV) which is printed on food labels in the U.S. and Canada.

Vitamins and minerals

RDI/AIs and ULs for a 25-year old male are shown below. ULs shown as "ND" could not be determined, and it is recommended that intake from these nutrients be from food only, to prevent adverse effects. Amounts and "ND" status for other age and gender groups, pregnant women, lactating women, and breastfeeding infants are different.

Nutrient	RDI/AI	UL	units per day
Vitamin A	5000	15000	IU
Vitamin C	90	2000	mg
Vitamin D	200	2000	IU
Vitamin K	120	ND	µg
Vitamin B6	1.3	100	mg
α-tocopherol (E)	15	1000	IU
Biotin	30	ND	µg
Boron	-	20	mg
Calcium	1000	2500	mg
Chloride	2300	3600	mg
Chromium	35	ND	µg
Choline	550	3500	mg
Copper	900	10000	µg
Cyanocobalamin (B12)	2.4	ND	µg
Fluoride	4	10	mg
Folate (B9)	400	1000	µg
Iodine	150	1100	µg
Iron	8	45	mg
Magnesium	420	350a	mg
Manganese	2.3	11	mg
Molybdenum	45	2000	µg
Niacin (B3)	16	35	mg
Nickel	-	1.0	mg
Pantothenic acid (B5)	5	ND	mg
Phosphorus	700	4000	mg
Potassium	4700	ND	mg
Thiamin (B1)	1.2	ND	mg
Riboflavin (B2)	1.3	ND	mg
Selenium	55	400	µg
Sodium	1500	2300	mg
Sulfate	-	ND	-
Zinc	11	40	mg

^a From pill only, not including food and water intake.

It is also recommended that the following substances not be added to food or dietary supplements. Research has been conducted into adverse effects, but was not conclusive in many cases:

Substance	RDI/AI	UL	units per day
Arsenic	-	ND	-
Silicon	-	ND	-
Vanadium	-	1.8	mg

Macronutrients

RDI/AI is shown below for males aged 19-30 years.

Waterb	3.7 L/day
Carbohydrates	130 g/day
Fiber	38 g/day
Fat	10 g/day
Linoleic acid, an omega-6 fatty acid (polyunsaturated)	17 g/day
alpha-Linolenic acid, an omega-3 fatty acid (polyunsaturated)	1.6 g/day
Proteinc	58 g/day
Cholesterol	As low as possible
Trans fatty acids	As low as possible
Saturated fatty acids	As low as possible
Added sugar	No more than 25% of calories

^bIncludes water from food, beverages, and drinking water.

^cDepends on body weight.

See also

• Healthy diet
• Acceptable daily intake (UK standards for toxicity)
• Vitamin poisoning
• Canada's Food Guide
• Food guide pyramid
• Dietary mineral
• Essential amino acid
• Essential fatty acid
• Essential nutrient
• Nutrient
• Vitamin

External links

• US Government Food and Nutrition Information Center list of Dietary Reference Intakes (DRI) and Recommended Dietary Allowances (RDA, the deprecated nutritional recommendations)
• USDA RDA chart (PDF file)
• USDA Reference Daily Intakes
• Article comparing recommended amounts of vitamins and minerals in different countries from the European Union (PDF file)
• Differences in RDA set by medical authorities in the UK, the European Union and the USA.

References

Nestle, Marion. "Food Politics." Berkeley: University of California Press, 2002.