Biofortification is “the process by which the nutritional quality of food crops is improved through agronomic practices, conventional plant breeding, or modern biotechnology” without sacrificing important culinary characteristics and key agronomic traits, such as pest resistance, drought resistance, and yield (WHO 2016). These modalities of biofortification can be combined. Crops biofortified with iron (e.g., high-iron pearl millet, high-iron beans) or biofortified with vitamin A (e.g., orange-fleshed sweet potato and pro-vitamin A maize and cassava) can reduce iron deficiency and vitamin A deficiency, respectively (Haas et al. 2011).

A variety of factors that impact the effectiveness of a biofortification program include—

  • Bioavailability (e.g., the increment by which the micronutrient level increases over baseline, levels of the micronutrient in the crop, genotype-by-environment—to ensure stability of mineral accumulation—and micronutrient retention during storage and cooking)
  • Viability (e.g., the planting material’s acceptability to farmers; drought, pest, and disease resistance; yield potential)
  • Potential reach (e.g., acceptability to consumers, including appearance, flavor, and cooking time; quantities grown versus saved for home consumption).

Measurement and data sources

A country’s National Agricultural Research System—the national institution with the mandate to breed, test, and release new crop varieties in-country—should maintain data on whether a crop is available, where it is available, as well as estimates of micronutrient content in the locally adapted variety. It is important to identify which, if any, biofortified varieties have been released, the prevalent forms of preparation, and the levels of consumption for each variety in your country.

Income expenditure surveys or market surveys may provide details about value chains or specific food items—information that can help establish to what extent and where the particular crop—biofortified or not—is available in a local area and whether households are buying it. Intakes of biofortified crops may be available via household surveys conducted by organizations working to promote biofortification.

Some household diet questionnaires may include specific information about consumption of biofortified crops, often using visual aids to help respondent recall. Surveys that include a food frequency, or list-based food questionnaire, may include questions on consumption of biofortified varieties.

To understand whether biofortification will effectively reduce micronutrient deficiencies, you should know the levels of each micronutrient in the locally adapted variety (raw and cooked) and use that information to estimate the intake by the target population. Outside the context of a program, consumption data may not be available, but knowing if and which biofortified crops are present, is an important first step.

HarvestPlus maintains a map that shows which countries have released or are testing biofortified crops, as well as other publications related to biofortification.

Methodological issues

  • Where biofortified crops are available, rollout takes time—particularly for roots, tubers, and other crops that reproduce vegetatively—and in those areas where no effective seed distribution systems is available.
  • Nutritional impact is ultimately related to the local market share occupied by the biofortified crops and the average daily consumption of the locally produced biofortified staple. Therefore, with the exception of orange-fleshed sweet potato, new programs are unlikely to widely impact a population’s micronutrient status for several years.
  • Many steps lie between biofortification and anemia reduction, including bioavailability and other factors—absorption may be higher for those who are deficient.