Michiel Korthals makes several incorrect assertions about biofortification as a strategy for tackling malnutrition in his letter to the editor Don't medicalise micronutrient deficiency.
First, biofortification is not "ignoring the food and agricultural aspects" of malnutrition. Rather, it explicitly accounts for the agricultural context of poorer rural communities in the developing world, where small-scale farmers mostly grow, and eat, staple food crops.
By breeding nutrients directly into staple foods, together with other agronomic traits farmers want — such as disease or drought resistance — biofortification is a way to improve the diets of the undernourished. Biofortification simply adds nutrients to other traits being developed for farmers.
Second, farmers participate in trials to select the varieties they prefer that also contain nutritional traits. This participation is a standard practice in developing agricultural technology.
In this way, biofortification is integrated into existing farming practices, and does not "require more water or land". Rather than being "pushed" on farmers, the entire approach is built on farmers' needs. Further, it is incorrect to assume that the seeds of biofortified crops will only be affordable to rich or commercial farmers, especially since most biofortification efforts to date focus on staple crops that the poor grow and eat.
Third, contrary to Korthals' assertion, biofortification does not force farmers to buy seed every year. It is true that if farmers plant hybrids, they cannot save seeds. But most crops planted in the developing world are not hybrids. For staple crops such as wheat, rice, sweet potato, open pollinated maize and cassava, regardless of whether they are biofortified or not, farmers can save their seed or planting material to share or replant.
Finally, while Korthals is correct in saying that malnutrition is a "multi-faceted problem", biofortification advocates have not disparaged other solutions. The enormous challenge of micronutrient malnutrition is best addressed in the long run through poverty alleviation, economic development, education, women's empowerment, access to adequate healthcare and dietary diversification, among other things.
In the interim, biofortification offers another tool to cost-effectively provide crucial micronutrients to millions of poor people in rural areas, through the foods that they already grow and eat every day.