Micronutrient deficiencies, or hidden hunger, afflict more than two billion individuals, or one in three people, globally. The effects can be devastating, leading to mental impairment, poor health and productivity, and even death. The decline in immunity to infections, cognitive impairment, and decreased work capacity that can result from hidden hunger has important socioeconomic implications, particularly in low- and middle-income countries.
A Different Kind of Hunger
Hidden hunger may occur when one or more vitamins and minerals important for human health are consistently inadequate in a person’s diet. Diets based mostly on staple crops, such as maize, wheat, rice, and cassava, which provide large amounts of energy but relatively low amounts of essential bioavailable vitamins and minerals, frequently result in hidden hunger.
Many victims of hidden hunger live in developing countries and consume diets that do not give them the minerals and vitamins they need, usually because they cannot afford or cannot access a wide range of nutritious foods such as animal-source foods (meat, eggs, fish and dairy), as well as fruits and vegetables. In some cases they lack the nutrition knowledge to understand the importance of a balanced diet. In non-emergency situations, poverty is a major factor that limits access to adequate, nutritious foods. When food prices rise, consumers tend to maintain their level of staple food consumption while reducing their intake of non-staple foods that tend to be richer in micronutrients.
A Different Kind of Solution
For the past few decades, hidden hunger has attracted increased international attention. In 1992, 159 countries endorsed the World Declaration on Nutrition, pledging “to make all efforts to eliminate. . . iodine and vitamin deficiencies” and “to reduce substantially. . . other important micronutrient deficiencies, including iron.” To address the problem, governments and international organizations enacted a range of approaches: supplementation; food-based strategies (food fortification, homestead food production); behavior change communication; and public health interventions (including environmental sanitation, deworming, and malaria control.)
Following the 1992 declaration, support for vitamin A supplementation and fortification for a variety of vitamins and minerals increased, and much progress has been made. For example, between 1999 and 2005, global efforts to ramp up vitamin A supplementation among children resulted in a fourfold increase in coverage rates, and in 2012, these programs achieved near 70 percent global coverage. These efforts entailed administering doses of Vitamin A to target populations over time and, as such, they largely depend on recurrent annual investments — from donors, NGOs or the public sector. As a result, coverage rates vary widely from year to year in many priority countries. Commercial food fortification, which adds trace amounts of micronutrients to staple foods or condiments during processing, is found to be a scalable, sustainable, and cost-effective public health strategy. Fortification has been particularly successful for some micronutrients. For example, 71 percent of the world’s population has access to iodized salt.
Fortification may be particularly effective for urban consumers who, by and large, purchase many commercially processed and fortified foods. Such interventions, however, are less likely to reach rural consumers who often have little to no access to commercially produced foods.
Biofortification is a complementary intervention to supplementation and fortification. It uses the crops farmers already grow and eat to deliver increased levels of micronutrients into the food system. When breeding food crops to increase their micronutrient content, plant breeders also improve various agronomic attributes, such as yield and pest resistance, in addition to consumption traits, such as taste and cooking time— that match or even outperform traditional varieties grown among target populations. Over one million farmers are currently growing biofortified crops—including vitamin A orange sweet potato, vitamin A maize, vitamin A cassava, iron beans, iron pearl millet, zinc rice, and zinc wheat— on their farms in several developing countries in Africa, Asia and Latin America and the Caribbean.
Because biofortified staple foods cannot deliver as high a level nor the optimum number of minerals and vitamins as supplements or industrially fortified foods, they are not the best response to chronic or severe micronutrient deficiencies. But they can help close the intake gap of targeted micronutrient deficiencies in most other cases and increase the daily intake of micronutrients throughout a person’s life cycle. Several crops (iron beans, pearl millet and rice, vitamin A cassava, maize and sweet potato) show promise with evidence of improved micronutrient status. Evidence on ex ante and ex post cost-effectiveness and population level nutrition impact shows biofortification to be a cost-effective and scalable intervention. Given the growing body of evidence and the increased interest and commitment of various governments, donors and the private sector, the scale of biofortification is expected to grow dramatically in the next five years.
As the Second International Conference on Nutrition (ICN2) approaches in November 2014, national policymakers, intergovernmental organizations, and civil society will review progress against their 1992 pledge. No single approach is a silver bullet to alleviate hidden hunger, but evidence increasingly demonstrates that biofortification is a critical tool for inclusion in the hidden hunger toolbox.