Iron and zinc are among the most important micronutrients needed in order to have good health and quality of life. The human body needs iron to make hemoglobin, which the body needs in order to transport oxygen from the lungs to other organs, and myoglobin, which transports oxygen to the muscles. Iron is also a key component of other hormones essential for growth and development. Zinc, on the other hand, activates enzymes of protein metabolism, and serves as a cofactor for up to 300 enzymes in the human body. It is important for immune function, cognitive development, and growth stimulation.

Iron and zinc deficiencies are the most pervasive forms of malnutrition worldwide and are key causes of anemia and stunting. According to the 2021 Global Nutrition Report, an estimated 30% of the world’s population is anemic and 162 million children under the age of five are stunted. Iron deficiency can affect productivity and cause serious health consequences, including impaired mental development and learning capacity, increased weakness and fatigue, and adverse pregnancy outcomes. Similarly, zinc deficiency is a major cause of stunting among children, putting them at risk of compromised cognitive development and physical capability, and a weak immune system.

Iron and zinc deficiencies, which are caused by chronic inadequate dietary intake of micronutrients, are a serious public health concern for all population groups, especially for children under 5 and pregnant and lactating women. In the Philippines, data from the 2023 National Nutrition Survey of the Department of Science and Technology-Food and Nutrition Research Institute (DOST-FNRI) shows that iron and zinc deficiencies continue to be a public health issue across all age groups, with iron as the micronutrient with the lowest supply in the typical Filipino diet. Anemia affects 21.8% of pregnant women and 17.2% older persons. Meanwhile, stunting continues to affect 23.6% children under five years old. Iron and zinc deficiency disproportionately affects the rural poor who do not have access to nutritionally balanced diets or micronutrient supplements. A UNICEF study on the economic consequences of malnutrition in 2017 revealed that stunting costs the Philippines over $3.1 billion annually in terms of productivity losses.

High Iron and Zinc Rice (HIZR) is a rice variety genetically modified to significantly improve iron and zinc content in the rice grain. Compared to regular rice, HIZR contains about five times more iron (up to 10 ppm) and twice as much zinc (up to 35 ppm). It is intended as a complementary intervention to help address anemia and stunting and aims to provide 30% of the Estimated Average Requirement (EAR) for iron and 40% EAR for zinc among target populations, such as children under 5, and pregnant and lactating women.

Iron is abundant in flooded soil, so there is typically no need to apply iron fertilizer in irrigated fields, but zinc content is limited in similar conditions, so zinc fertilizer is recommended for optimum nutrient management. An abundant supply of soil nutrients leads to good plant growth but does not lead to an increase in nutrients in the grain. The 16-ppm baseline zinc content of the rice grain is not increased by the addition of zinc fertilizer to soil, but zinc content in rice will decrease when the soil is severely zinc deficient. A foliar application can moderately increase iron and zinc content in the rice grain, but not as much as the iron and zinc content established in the HIZR proof of concept.

Although conventionally bred high-iron and high-zinc rice varieties contain elevated levels of these micronutrients, they have not reached the nutritional target thresholds established by HarvestPlus for meaningful public health impact. HarvestPlus sets these targets based on the amount of micronutrients needed to improve the nutritional status of women and children, while also accounting for daily rice consumption, nutrient losses during processing and cooking, and the bioavailability of the nutrients. For zinc-biofortified rice, HarvestPlus established a target concentration of 28 ppm zinc in polished rice, compared with the baseline level of about 16 ppm in conventional rice varieties, to help provide a significant proportion of the EAR for vulnerable populations. Likewise, HarvestPlus established a target of 10 ppm iron in polished rice to contribute meaningfully to iron nutrition. A major limitation of conventionally bred high-iron and high-zinc rice is that much of the micronutrient content is concentrated in the bran layer, which is largely removed during the milling process. As a result, the nutritional gains are substantially reduced in the polished rice that consumers actually eat. In contrast, advanced biotechnology approaches used in the development of HIZR ensure that the additional iron and zinc are expressed in the endosperm — the edible portion of the grain retained after milling. This allows the enhanced micronutrient levels to remain present in milled rice and enables HIZR to meet the nutritional targets required for improved public health outcomes nutrition status.

In the process of developing HIZR, scientists added a gene from rice responsible for iron and zinc movement from plant roots and leaves into the rice grain. This was combined with ferritin genes from apple to enhance iron storage capacity of the grain. This particular protein is a primary source of iron for people following vegetarian diets and is readily absorbed by the human body. HIZR targets the development of rice lines with at least 10ppm iron and 28ppm zinc in the milled grain. This level potentially meets the nutritional target to provide 30-50% of the EAR for at-risk populations.

During the course of HIZR research and development, IRRI’s research partner, HarvestPlus determined that rice should be able to provide around 10 ppm Fe and 28 ppm Zn in the milled form, in order to make a significant impact on human health. This corresponds to 30% of the estimated average requirement (EAR) for iron and 40% EAR for zinc, and takes into account the daily micronutrient consumption of women and children, as well as the baseline content and bioavailability of micronutrients in rice. These intended target levels also take into account potential micronutrient loss in the rice grain after it has undergone postharvest and cooking processes.

No. Eating biofortified rice is not expected to cause iron (Fe) or zinc (Zn) overdose under normal dietary conditions. Biofortified rice is designed to help address micronutrient deficiencies by modestly increasing the levels of iron and zinc in a staple food that people already consume daily. The target concentrations established by HarvestPlus are intended to provide only a portion of the recommended daily requirement, not excessively high amounts. The zinc and iron targets are designed to improve intake while remaining within safe dietary ranges. These levels are far below the amounts associated with toxicity. In addition, the human body has natural regulatory mechanisms for iron and zinc absorption: Iron absorption decreases when body iron stores are sufficient. Zinc absorption is also regulated, and excess zinc is generally excreted. To reach toxic levels from rice alone, a person would need to consume unrealistically large quantities over a prolonged period. In practice, the greater public health concern globally — especially in rice-consuming populations — is deficiency rather than excess iron or zinc.

DA-PhilRice submitted a technical dossier for regulatory applications for commercial propagation to the DA-BPI on October 24, 2025. Following the completion of the required biosafety regulatory assessments, a biosafety permit for commercial propagation was issued on April 27, 2026, marking a key milestone toward potential deployment. Moving forward, efforts will focus on advancing through continued breeding and field development. By improving its field performance, HIZR aims to provide a sustainable, food-based source of iron and zinc for communities where micronutrient deficiencies remain prevalent.