Severity of zinc and iron malnutrition linked to low intake through a staple crop: a case study in east-central Pakistan

Micronutrients deficiency in soil–plant and human is well-addressed; however, little is known about their spatial distribution, magnitude of deficiency and biological nexus. Zinc deficiency (ZnD) and iron-deficiency anemia (FeD) are two serious nutritional concerns which are negatively affecting human health. Herein, a survey-based case study was conducted in major wheat-based cropping system of east-central Pakistan. Soil and grain samples were collected from 125 field-grown wheat from 25 distinct sites/villages and GPS coordinates were taken for mapping. The collected samples were tags according to the names of 25 sites, i.e., UCs (union councils; an administrative unit). The quantified amount of zinc (Zn) or iron (Fe) in soil-wheat grains was compared with their recommended concentrations (RCZn, RCFe) for human nutrition. Additionally, clinical features of ZnD and FeD were diagnosed among local farmers who used to consume these grains, throughout the year, cultivated on their farm, and quantified their deficiency prevalence (ZnDP, FeDP). Results revealed, the collected 64% (0.54 to 5.25 mg kg−1) soils, and 96% (1.4 to 31 mg kg−1) grain samples are Zn-deficient (RCZn) along with ZnDP recorded among 68% of population. Meanwhile, FeD is quantified in 76% (1.86 to 15 mg kg−1) soil, 72% grain (2.1 to 134 mg kg−1) samples, and FeDP is found among 84% of studied population. A strong and positive correlation is developed in the Zn-or FeDP with their deficiencies in soil and grain by plotting multivariate analysis. In line with spatial distribution pattern, the UCs, namely, 141, 151, 159 and 132 are quantified severe deficient in Zn and Fe, and others are marginal or approaching to deficient level. Our findings rationalize the biological nexus of Zn and Fe, and accordingly, draw attention in the biofortification of staple crop as a win–win approach to combat the rising malnutrition concerns.