Know-how & Knowledge
Micronutrient requirements and intake recommendations
Micronutrients such as vitamins and carotenoids are required in small amounts in the diet but are essential for life and good health. A lack of particular micronutrients causes a number of health problems. Health can potentially be affected by a lack of micronutrients if people have a poor diet over a long period of time. Particular groups of people are more likely to be affected: the older generations, pregnant and lactating women, children, those on low incomes and migrant populations.
Currently, each country in Europe has its own set of recommendations to say how much of each micronutrient should be included in the daily diets of adults, children and particular population groups. For many vitamins these recommendations are different as each country has set them in different years, and in each year the scientific evidence evolves. Also each country has used different methods to reach its conclusions and looked at different population and age groups. The result is confusion for policy-makers, health professionals and consumers, as well as food producers and retailers.
The health authorities’ recommendations for micronutrient intake are involved across food and nutrition policy in areas such as the declaration of amounts of micronutrients in foods, planning food supplies, and assessing the nutritional adequacy of population groups. For the latter most countries tend to use their own nationally-derived values which can vary considerably.
In order to update the almost 20 year-old recommendations, the European Commission asked the European Food Safety Authority (EFSA) to advise on values for micronutrient recommendations, after first advising on existing values for energy, macronutrients and dietary fiber. The work on micronutrients was initiated in 2008. Expert panels are expected to develop a general framework of nutrition and food policy in the near future.
The aim is to produce Europe-wide scientific consensus on the evidence on which micronutrient recommendations can be used, enabling such evidence to be converted rapidly, conveniently and appropriately into recommendations published in national policy documents. In this process, not only nutrition science but also each nation’s social, cultural and ethical differences need to be considered.
In addition, the EFSA strives to establish uniform dietary reference values designed to ensure a diet that provides energy and nutrients for lifelong optimal growth, development, function and health. It seeks to remove the existing confusion over competing classification systems, such as the European ‘Dietary Reference Values’ and the ‘Recommended Dietary Allowances’ used in the U.S.
Following a request by the European Commission, the Scientific Committee on Food (SCF) set in 2003 recommended values on nutrient intakes for the European community, which include
- The ‘Population Reference Intake (PRI)’, in most countries called ‘Recommended Daily Allowances (RDAs)’, defines an adequate nutrient intake level that most, if not all, individuals of a population or a specific population group should obtain to satisfy their requirements.
- The ‘Average Requirement (AR)’ is the level of (nutrient) intake that is adequate for half of the people in a population group, given a normal distribution of requirement.
In addition, so-called ‘Reference Labeling Values (RLVs)’ are used to enable the (micro)nutrient content of a food product (per 100 g, per 100 ml, or per portion) to be expressed as a percentage of reference values for intake of adults. This information allows comparison of the nutritional values of food products and can help to convey their relative significance as a source of nutrients and energy in a total daily diet. Nutrition labeling is considered as one of the ways to inform the consumer about the nutritional value of certain foods so that they can choose individual foods or an overall diet that are appropriate to their individual needs.
In the U.K., the ‘Dietary Reference Values (DRVs)’ comprise estimates of the amount of nutrients needed by different groups of healthy people in the population.
- The ‘Reference Nutrient Intake (RNI)’ is an estimate of the amount of a nutrient that should meet the needs of most of the group to which it applies; it is not a minimum target.
- The ‘Lower Reference Nutrient Intake (LRNI)’ is an estimate of the amount of a nutrient that is enough for only the small number of people who have low requirements (2.5%); the majority needs more.
In the U.S., recommendations for micronutrient intake are provided in the ‘Dietary Reference Intakes (DRIs)’ developed by the Institute of Medicine’s Food and Nutrition Board (FNB). DRI is the general term for a set of reference values used for planning and assessing nutrient intake in healthy people.
The DRIs include two reference values referring to micronutrient requirements:
- The ‘Recommended Dietary Allowance (RDA)’ recommends the average daily dietary intake level that is sufficient to meet the nutrient requirements of nearly all (97%–98%) healthy individuals in each age and gender group.
- An ‘Adequate Intake (AI)’ is set when there are insufficient scientific data to establish an RDA. An AI meets or exceeds the estimated amount needed to maintain nutritional adequacy in nearly all people.
For a detailed overview of recommended daily intakes (PRIs/RDAs) of vitamins and minerals for adults derived from different countries and organizations see PDF
Following a request by the European Commission, the European Food Safety Authority (EFSA) has established, where possible, ‘Tolerable Upper Intake Levels (UL)’ for different population groups based on comprehensive evaluations of possible adverse health effects of individual micronutrients at intakes in excess of dietary requirements.
The context of this request was the need for scientific advice on the safety of micronutrients to support the implementation of impending harmonized EU legislation for food supplements and fortified foods, and particularly to assist with the setting of maximum limits for micronutrients in these products.
The tolerable upper intake level (UL) defines the maximum level of total daily intake of a nutrient (from all sources) judged to be unlikely to pose a risk of adverse health effects to humans.
The U.S. Institute of Medicine’s Food and Nutrition Board (FNB) has defined ‘Tolerable Upper Intake Levels (UL)’ as part of the ‘Dietary Reference Intakes (DRIs)’.
The UL defines the maximum daily intake unlikely to result in adverse health effects.
For a comparison of the upper safe levels for total daily intake of vitamins and minerals for adults from European, U.S., and U.K. health authorities see PDF
Some values differ between countries as the scientific evidence used to establish some figures were not always the same.