Appendix 8: Vitamin A content of foot

Analytical values for the vitamin A contents of food for a particular country or region can generally be found by contacting the national health authorities, or through the nutrition and/or agricultural offices in the Capital. Analytical techniques are updated from time to time and the most recent tables should be consulted.

Usually, in tables of food composition, vitamin A contents of food are expressed as IUs (International Units) or REs (Retinol Equivalents). The more recent tables use REs. In most tables, REs incorporate contents of retinol and carotene. In some food items, both of these forms are found, although animal food contains mostly retinol and plant food contains carotene.

Vitamin A contents are quite variable in different food items, and even within a particular food item grown in different parts of the world or exposed to different climatic handling/storage/preparation conditions. The highest levels of vitamin A are found in natural food items such as the livers of animals, carrots, red palm oil, and certain green vegetables and fruits. A recent publication entitled Food Sources of Vitamin A and Provitamin A was published in the UNU Food and Nutrition Bulletin 1992, 14(1):3-35. Another excellent source explaining the vitamin A levels of food is a publication from the International Vitamin A Consultative Group (IVACG) entitled Guidelines for the Development of a Simplified Dietary Assessment to Identify Groups at Risk for Inadequate Intake of Vitamin A. In 1993, C. West and E. Poortvliet released a publication for the Vitamin A Field Support Project called The Carotenoid Content of Foods with Special Reference to Developing Countries, which is a compilation of data on the vitamin A content of foods consumed around the world.

A general rule for vitamin A contents of food is to look at the color or to consider the part of the animal. Dark green vegetables, yellow and red fruits (excluding citrus) and vegetables, and red palm oil are rich sources of carotenoids. Animal sources include liver and organ meat, red meat, whole fish and fish oils, egg yolk, dairy products, and breastmilk. A range of values for vitamin A contents in food, together with a rating value to use in Module 5 tabulations is shown in the table below. While it is best to get a specific vitamin A value from a food composition source of original data, using an equivalent to guess at a rating is sufficient for the exercise in Module 5.

Keep in mind that substantial vitamin A can be added to the diet by eating small amounts of food high in vitamin A or larger amounts of food with modest levels of vitamin A. The bioavailability of vitamin A in food is also worth considering, and foods high in vitamin A must contain several properties for the vitamin A to be used by the body. Food must be palatable to the individual so that it is swallowed, and it must be digested; the diet must also have sufficient fat, protein, energy, and other key nutrients for dietary vitamin A to be utilized in the body.

Recommended levels of dietary vitamin A have been published by the Food and Agricultural Organization (FAO) of the United Nations in 1988, and are presented on the next page.

Examples of Food with Approximate Levels of Vitamin A and Rating Value to Use in Module 5

NOTE. Values from Booth et al. (1992) and as reported in tables from regions where the manual was tested.

Rating Values to Calculate Vitamin A Contents of Diets

FAO Recommended Dietary Intakes of Vitamin A (RE)