Common Nutrition Abbreviations

Nutrition abbreviations can look like alphabet soup.
Kenneth C. Zirkel

IU, RDA, DRI, g, mg? All those letters can start to look like alphabet soup. But, they're just a few abbreviations you'll find on this website (and many other websites, too).

When you read articles about nutrition, diet, and nutritional supplements, you're likely to come across some abbreviations. Here's a list of the ones you'll see most often.

AA - Amino Acids: the individual components of proteins.

ADEK - Vitamins A, D, E, and K: fat-soluble vitamins sometimes grouped together and designated by the abbreviation ADEK.

AI - Adequate Intake: the amount of a nutrient that will meet the requirements of everybody. It is used when an RDA can't be determined.

BMI - Body Mass Index: a measurement that indicates obesity by calculating the relative percentages of fat and muscle in the body.

Ca - Calcium: a dietary mineral needed for healthy bones and teeth, normal blood clotting, and nerve and muscle function.

DRI - Dietary Reference Intake:, the levels of nutrients needed for dietary consumption. They replaced the Recommended Dietary Allowance (RDA) in 1989.

EAR - Estimated Average Requirement: the intake of a nutrient that will meet the requirements of one-half of all healthy individuals.

Energy RDA - Energy Recommended Dietary Allowance: the average number of calories needed, differing by sex and age.

Note: The Energy RDA is an average, so any person may actually need more calories or fewer calories than what the calorie charts show.

Fe - Iron: a dietary mineral required for transportation of oxygen throughout the body.

FTT - Failure to Thrive: a significant delay in growth of an infant or young child.

g - Gram: a metric unit of measure. Carbohydrates, fats, and proteins are measured in grams. One ounce is about 29 grams.

IU - International Unit: a measure of the activity of vitamins and drugs. Vitamins A, D and E are often measured in this way. Conversion from IU to mg is different for each vitamin.

K - Potassium: a dietary mineral that is needed for water balance and healthy muscle function in the body.

kcal - Kilocalorie: a measure of energy that we commonly refer to as a "calorie."

mcg - Microgram, a metric unit of measure. Some vitamins and minerals are measured in micrograms, for example, 1,000 micrograms equal one milligram.

mg - Milligram: another metric unit of measure. Many vitamins and minerals are measured in milligrams, for instance, 1,000 milligrams equal one gram.

Mg - Magnesium: a dietary mineral needed for healthy muscle function and other processes in the body.

mEq - Milliequivalent: a measurement that is equal to one-thousandth of a gram equivalent.

Na - Sodium - a dietary mineral that is needed for water balance in the body.

RDA - Recommended Dietary Allowance: designates the amount of a nutrient that will meet the requirements of 97.5 percent of healthy individuals. It is based on the EAR plus two standard deviations.

REE - Resting Energy Expenditure: number of calories you would burn if you stayed at rest all day.

RNI - Reference Nutrient Intake: used in the UK and stands for the daily nutrient recommendations to meet the needs of the majority of the population.

UL - Tolerable Upper Limit: highest level of a nutrient that is safe for all individuals.


Gropper SS, Smith JL, Groff JL. "Advanced Nutrition and Human Metabolism." Sixth Edition. Belmont, CA. Wadsworth Publishing Company, 2013. 

The United States Departments of Agriculture and Health and Human Services. "Dietary Guidelines for Americans 2015-2020."  

Continue Reading