Background Information and References

This website uses nationally representative nutrient intake data from the United States to give estimates of average intakes for a variety of age, gender, ethnicity and household income groups. It is designed as a tool for professionals working in the field of public health nutrition to determine usual intake levels of various nutrients for use in research and designing nutrition interventions. The demographic, income and ethnicity data can be used to target interventions that address risk groups and are culturally sensitive.

About the Data

The data presented in the Micronutrient Calculator were obtained from the National Health and Nutrition Examination Survey (NHANES), a nationally representative survey designed to assess the health and nutritional status of adults and children living in the United States of America. Data were selected from the continuous NHANES in the three cycles 2003-2004, 2005-2006 and 2007-2008.

Data from 24,554 individuals aged above 2 years who had completed the dietary intake assessment were used to calculate the summary information. Pregnant females were excluded from the dataset. Nutrient intakes were estimated by linking survey foods to food composition data provided by the latest available Nutrient Database for Standard Reference at the time of release.

Average intakes reflect the "Usual Intake", an estimation of long-term food intake. The National Cancer Institute methods were used to determine this "Usual intake," calculated based on the nutrient intake of two 24-hour dietary recall assessments given on non-consecutive days for each individual participating in the survey.

Ethnicity Categories

The ethnicity categories used in the Micronutrient Calculator are the three largest in the US population. Ethnicity was selected by participants and based on the question "What race do you consider yourself to be? Please select one or more of these categories" from the NHANES survey demographic questionnaire. The standard US Census categories were provided for participants to select from, including White, Black/African American, Native American and Alaska Native. In addition, Latino participants were asked to identify what country their ancestors were from (Puerto Rico, Mexico, Cuba, Dominican Republic, Central/South American, or Other). As there are some differences in dietary patterns between different Latino groups, only the largest group, the Mexican Americans, was chosen for the Micronutrient Calculator, along with the White and Black/African American ethnicity categories.

Recommended Intake Levels

Dietary Reference Intakes set by the Institute of Medicine (IOM) were used for recommended intakes of macronutrients, vitamins and minerals.

The Estimated Average Requirement (EAR) is defined by the IOM as "the average daily nutrient intake level that is estimated to meet the requirements of half of the healthy individuals in a particular life stage and gender group" (IOM, 2006). Therefore, the EAR will meet the needs of half of the population and is used to calculate population sufficiency.

The Recommended Dietary Allowance (RDA) is defined by the IOM as "the average daily dietary nutrient intake level that is sufficient to meet the nutrient requirements of nearly all (97-98 percent) healthy individuals in a particular life stage and gender group" (IOM, 2006). It is used to estimate requirements for individuals.

The Adequate Intake (AI) is used when the evidence base for that particular nutrient was not extensive enough to calculate an RDA. It is "based on observed or experimentally determined approximations of estimates of nutrient intake" (IOM, 2006).

Where possible, EARs were used because these reflect population nutrient goals rather than for individuals. For iron and potassium, analyses using the EAR were not available therefore the RDA was used. The nutrients choline, fiber and vitamin K only have an Adequate Intake (AI) set. In the time between the main data analyses and the publication of this website, the AI for calcium and vitamin D was converted to a RDA/EAR. There is no estimation of the "percent below" for vitamin D due to this, however the data indicates almost all people do not meet the AI.

Intake levels provided by the IOM are listed under the following age categories for both genders to reflect changing needs through different stages of growth and development:

  • 0 to 6 months
  • 7 to 12 months
  • 1 to 3 years
  • 4 to 8 years
  • 9 to 13 years
  • 14 to 18 years
  • 19 to 30 years
  • 31 to 50 years
  • 51 to 70 years
  • Older than 70 years

The Micronutrient Calculator provides Dietary Reference Intake (DRI) information about each of these age categories. In addition, broader age categories are available, as well as data from both genders combined. For these broader categories DRI information is still provided, however it is expressed as a range. If only two different DRIs are present, the DRIs have a slash between them, for example the EAR for vitamin A in toddlers is 210 RAE and in young children aged 4 to 8 it is 275. For the category "Toddlers and young children", the EAR is expressed as 210/275 RAE. When more than two categories are covered, a hyphen is used. Using vitamin A intakes as an exampe for everyone aged over 2, the EAR is expressed as 210-625 RAE to reflect the range of recommended intakes for all age groups.

Background Behind Protein Intake Recommendations

Protein intake recommendations are given based on weight. The minimum amount of protein per kilogram body weight also changes depending on age, reflecting the decreasing rate of growth from newborns to adults. Therefore, average weights for healthy infants, children and adults were used in order to provide guidance on how much protein is needed to meet the average person's requirements. Average weights as shown in the following table were used to calculate average protein intakes for each age category. For ages spanning multiple categories, a weighted average was used.

Adapted from: Institute of Medicine. Dietary Reference Intakes: Protein. 2006. National Academies Press, Washington DC, USA.
Average Weight for Age Categories Males (kg) Females (kg)
2 to 3 years 14 13
4 to 8 years 21 20
9 to 13 years 36 37
14-18 years 61 54
19-30 years 71 58
31 to 50 years 71 58
51-70 years 71 58
71+ years 71 58

Background Behind Carotenoid Targets

Carotenoids are highly colored plant pigments obtained in the diet mainly through fruit and vegetable intake. There are no recommended intakes set by scientific or regulatory bodies in the USA. Target intakes for total carotenoids were set based on carotenoid intakes of people meeting recommendations for fruit and vegetable intakes (Murphy et al., 2012).

Adapted from: Murphy et al.. J Am Diet Ass. Feb 2012.
Usual mean carotenoid intake of people meeting fruit and vegetable intakes (μg/day, absolute) Males Females
Alpha-carotene 1,012 886
Beta-carotene 4,679 4,818
Beta-cryptoxanthin 375 264
Lutein/zeaxanthin 3,195 3,611
Lycopene 11,834 7,339
Total carotenoids 21,095 16,918

Why Do Age, Gender, Income and Ethnicity Change Nutrient Intakes?

How do individuals decide what they are going to eat every day? Food choices determine the nutritional content of the diet as a whole. Nutrient intakes vary a great deal from day to day and between individuals. Various factors lie behind decisions about what foods to eat. This comes down to personal food preferences, access to food, cultural practices, activity levels, health status and knowledge of nutritional issues. Despite this wide variation, some patterns exist for sections of the population, which relate to trends in factors governing food choices. This website provides average nutrient intakes for gender, age, household income and ethnicity groups in the USA. The reasons behind these differences are briefly discussed below.


Nutritional needs, body size, activity levels, physical attributes and food preferences change throughout the life span. Newborn infants drink only milk then gradually incorporate other foods into the diet as they develop teeth and the ability to chew foods and feed themselves. Increasing food intakes match developmental milestones such as crawling and walking that can increase energy expenditure. Individual preferences come into play in the toddler years. Growth rates slow as we grow, however body size generally increases until a maximum height is achieved in adolescence, changing nutrient needs and intakes. The increasing independence of children from the family home through the teenage years can affect food and nutrient intakes. At the other end of the aging spectrum, health and disease affect dietary choices in adulthood. The elderly often have different nutritional needs to adults as their metabolism slows, yet they may have difficulties absorbing nutrients due to changes in denture and the gastrointestinal tract and maintaining food intakes when aging affects sensory qualities of food.

Infants: MedlinePlus. Infant and Newborn Nutrition. Updated August 24, 2012.
Toddlers: Cowbrough K. Feeding the toddler: 12 months to 3 years--challenges and opportunities. J Fam Health Care. 2010;20(2):49-52.
Children: Baylor College of Medicine. Children's Nutrition Research Center. Baylor College of Medicine. Updated July 25, 2012.
Adolescents: California Department of Public Health. Adolescent Nutriiton. March 2012.
The Elderly: Kuczmarski MF, Weddle DO; American Dietetic Association. Position paper of the American Dietetic Association: nutrition across the spectrum of aging. J Am Diet Assoc. 2005 Apr;105(4):616-33.


There are a number of biological differences between men and women that affect food and nutrient intakes. Men generally have a higher body weight, larger muscle mass and are more likely to be involved in occupations requiring physical activity. Therefore total nutrient intakes tend to be higher in men than in women. In addition, studies have found differences in the types of food eaten by men and women: men are more likely to eat meat and poultry, whereas women have higher fruit and vegetable intakes.

Marino M, Masella R, Bulzomi P, Campesi I, Malorni W, Franconi F. Nutrition and human health from a sex-gender perspective. Mol Aspects Med. 2011 Feb;32(1):1-70. Epub 2011 Feb 26.
Shiferaw B, Verrill L, Booth H, Zansky SM, Norton DM, Crim S, Henao OL. Sex-based differences in food consumption: Foodborne Diseases Active Surveillance Network (FoodNet) Population Survey, 2006-2007. Clin Infect Dis. 2012 Jun;54 Suppl 5:S453-7.


The current median US household income in the US is around $50,000 (US Census Bureau, 2011). Income affects food choices not just at the lower end of the income spectrum, when the ability to provide enough food may be limited by finances. Factors that can contribute to higher incomes such as education and a stable family situation affect intakes.

Kirkpatrick SI, Dodd KW, Reedy J, Krebs-Smith SM. Income and race/ethnicity are associated with adherence to food-based dietary guidance among US adults and children. J Acad Nutr Diet. 2012 May;112(5):624-635.e6. Epub 2012 Apr 25.


Individuals within an ethnic group often share similar cultural practices relating to food. Traditional cuisines or the availability of certain produce within one geographical area may affect the foods eaten within one ethnic group. Many cultures use certain foods to celebrate culturally important events. Familiarity with a certain cuisine can ensure that common themes in food choices are passed from one generation to the next. Cultural norms relating to body size and what constitutes a healthy appetite can also influence nutrient intakes.

Dirks RT, Duran N. African American dietary patterns at the beginning of the 20th century. J Nutr. 2001 Jul;131(7):1881-9.
Evans A, Chow S, Jennings R, Dave J, Scoblick K, Sterba KR, Loyo J. Traditional foods and practices of Spanish-speaking Latina mothers influence the home food environment: implications for future interventions. J Am Diet Assoc. 2011 Jul;111(7):1031-8.


The following resources were used as references for the information about the nutrients.

Murphy MM, Barraj LM, Herman D, Bi X, Cheatham R, Randolph RK. (2012) Phytonutrient Intake by Adults in the United States in Relation to Fruit and Vegetable Consumption. J Am Diet Assoc. Feb;112(2):222-9.

National Research Council. Dietary Reference Intakes: The Essential Guide to Nutrient Requirements. Washington, DC: The National Academies Press, 2006. Download here

Whitney, E and Rady Rolfes S. Understanding Nutrition (2008) Thomson Wadsworth, Belmont, CA, USA