Common Nutrition and Diet Abbreviations

IU, RDA, DRI, g, mg... All those letters can start to look like alphabet soup. When you read articles about nutrition, diet, and nutritional supplements, you're likely to come across some abbreviations.

Here are some of the most common nutrition and diet abbreviations explained:

AA— Amino acids: the individual components of proteins.

ADEK— Vitamins A, D, E, and K: fat-soluble vitamins that are sometimes grouped together.

AI— Adequate intake: the amount of a nutrient that will meet an individual's daily requirements. It's used when a recommended dietary allowance (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 general levels of nutrients needed for dietary consumption. DRI includes recommended dietary allowance (RDA), adequate intake (AI), and tolerable upper intake level (UL).

EAR— Estimated average requirement: the intake level 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 individuals need, 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 the 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's 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's equal to one-thousandth of a gram equivalent.

Na— Sodium: a dietary mineral that's needed for water balance in the body.

RDA— Recommended dietary allowance: ​RDA designates the amount of a nutrient that will meet the requirements of 97.5 percent of healthy individuals. It's based on the EAR plus two standard deviations.

REE—​Resting energy expenditure: the number of calories you would burn if you stayed at rest all day.

RN—​​Reference nutrient intake: used in the UK, it stands for the daily nutrient recommendations to meet the needs of the majority of the population.

UL—​Tolerable upper intake level: the highest level of a nutrient that's safe for all individuals.