Next Generation Nutrition: Genomic and Molecular Breeding Innovations for Iron and Zinc Biofortification in Rice

Global efforts to address malnutrition and hidden hunger, particularly prevalent in low- and middle-income countries, have intensified, with a focus on enhancing the nutritional content of staple crops like rice. Despite serving as a staple for over half of the world's population, rice falls short in meeting daily nutritional requirements, especially for iron(Fe) and zinc(Zn). Genetic resources, such as wild rice species and specific rice varieties, offer promising avenues for enhancing Fe and Zn content. Additionally, molecular breeding approaches have identified key genes and loci associated with Fe and Zn accumulation in rice grains. This review explores the genetic resources and molecular mechanisms underlying Fe and Zn accumulation in rice grains. The functional genomics involved in Fe uptake, transport, and distribution in rice plants have revealed key genes such as OsFRO1, OsIRT1, and OsNAS3. Similarly, genes associated with Zn uptake and translocation, including OsZIP11 and OsNRAMP1, have been identified. Transgenic approaches, leveraging transporter gene families and genome editing technologies, offer promising avenues for enhancing Fe and Zn content in rice grains. Moreover, strategies for reducing phytic acid(PA) content, a known inhibitor of mineral bioavailability, have been explored, including the identification of low-PA mutants and natural variants. The integration of genomic information, including whole-genome resequencing and pan-genome analyses, provides valuable insights into the genetic basis of micronutrient traits and facilitates targeted breeding efforts. Functional genomics studies have elucidated the molecular mechanisms underlying Fe uptake and translocation in rice. Furthermore, transgenic and genome editing techniques have shown promise in enhancing Fe and Zn content in rice grains through the manipulation of key transporter genes. Overall, the integration of multi-omics approaches holds significant promise for addressing global malnutrition and hidden hunger by enhancing the nutritional quality of rice, thereby contributing to improved food and nutritional security worldwide.

The Impact of Nitrogen-Fixing Bacteria, Iron, and Zinc Foliar Application on Dry Land Yellow Mustard (Brassica juncea) Grain and Oil Production

The study, conducted at the Research Farm of the College of Agriculture, University of Tabriz in 2021, focused on the effects of various nitrogen-fixing bacterial isolates, biofertilizers containing nitrogen and phosphorus, as well as iron and zinc foliar applications on mustard growth under rainfed conditions. The results indicated that biofertilizers, whether used alone or in combination with chemical fertilizers, produced comparable grain and oil outputs compared to chemical fertilizers alone. Additionally, the application of iron and zinc through foliar spraying significantly enhanced both grain and oil production. These findings suggest that integrating nitrogen-fixing bacteria and biofertilizers could reduce reliance on chemical nitrogenous fertilizers, leading to decreased production expenses, improved product quality, and minimized environmental impact. This study highlights the potential for sustainable agricultural practices in dry land farming as a viable alternative to traditional chemical-intensive methods. Substituting chemical nitrogenous fertilizers with nitrogen-fixing bacteria or biofertilizers could result in cost savings in mustard grain and oil production while promoting environmental sustainability.

Application of Zinc, Iron and Boron Enhances Productivity and Grain Biofortification of Mungbean

Deficiencies of essential vitamins,iron(Fe),and zinc(Zn)affect over one-half of the world’s population.A significant progress has been made to control micronutrient deficiencies through supplementation,but new approaches are needed,especially to reach the rural poor.Agronomic biofortification of pulses with Zn,Fe,and boron(B)offers a pragmatic solution to combat hidden hunger instead of food fortification and supplementation.Moreover,it also has positive effects on crop production as well.Therefore,we conducted three separate field experiments for two consecutive years to evaluate the impact of soil and foliar application of the aforementioned nutrients on the yield and seed biofortification of mungbean.Soil application of Zn at 0,4.125,8.25,Fe at 0,2.5,5.0 and B at 0,0.55,1.1 kg ha−1 was done in the first,second and third experiment,respectively.Foliar application in these experiments was done at 0.3%Zn,0.2%Fe and 0.1%B respectively one week after flowering initiation.Data revealed that soil-applied Zn,Fe and B at 8.25,5.0 and 1.1 kg ha−1,respectively,enhanced the grain yield of mungbean;however,this increase in yield was statistically similar to that recorded with Zn,Fe and B at 4.125,2.5 and 0.55 kg ha−1,respectively.Foliar application of these nutrients at flower initiation significantly enhanced the Zn contents by 28%and 31%,Fe contents by 80%and 78%,while B contents by 98%and 116%over control during 2019 and 2020,respectively.It was concluded from the results that soil application of Zn,Fe,and B enhanced the yield performance of mungbean;while significant improvements in seed Zn,Fe,and B contents were recorded with foliar application of these nutrients.

Efficient degradation of dye pollutants in wastewater via photocatalysis using a magnetic zinc oxide/graphene/iron oxide-based catalyst

In this paper, we present a proof-of-concept study of the enhancement of photocatalytic activity via a combined strategy of fabricating a visible-light responsive ternary heterostructure and improving overall photostability by incorporating magnetic zinc oxide/graphene/iron oxide (ZGF). A solvothermal approach was used to synthesize the catalyst. X-ray diffraction (XRD), scanning electron microscopic, energy dispersive X-ray, transmission electron microscopic, vibrating sample magnetometric, and ultraviolet–visible diffuse reflectance spectroscopic techniques were used to characterize the synthesized samples. The obtained optimal Zn(NO_(3))_(2) concentration, temperature, and heating duration were 0.10 mol/L, 600℃, and 1 h, respectively. The XRD pattern revealed the presence of peaks corresponding to zinc oxide, graphene, and iron oxide, indicating that the ZGF catalyst was effectively synthesized. Furthermore, when the developed ZGF was used for methylene blue dye degradation, the optimum irradiation time, dye concentration, catalyst dosage, irradiation intensity, and solution pH were 90 min, 10 mg/L, 0.03 g/L, 100 W, and 8.0, respectively. Therefore, the synthesized ZGF system could be used as a catalyst to degrade dyes in wastewater samples. This hybrid nanocomposite consisting of zinc oxide, graphene, and iron oxide could also be used as an effective photocatalytic degrader for various dye pollutants.

Recent Developments in Metallic Degradable Micromotors for Biomedical and Environmental Remediation Applications

Synthetic micromotor has gained substantial attention in biomedicine and environmental remediation.Metal-based degradable micromotor composed of magnesium(Mg),zinc(Zn),and iron(Fe)have promise due to their nontoxic fuel-free propulsion,favorable biocompatibility,and safe excretion of degradation products Recent advances in degradable metallic micromotor have shown their fast movement in complex biological media,efficient cargo delivery and favorable biocompatibility.A noteworthy number of degradable metal-based micromotors employ bubble propulsion,utilizing water as fuel to generate hydrogen bubbles.This novel feature has projected degradable metallic micromotors for active in vivo drug delivery applications.In addition,understanding the degradation mechanism of these micromotors is also a key parameter for their design and performance.Its propulsion efficiency and life span govern the overall performance of a degradable metallic micromotor.Here we review the design and recent advancements of metallic degradable micromotors.Furthermore,we describe the controlled degradation,efficient in vivo drug delivery,and built-in acid neutralization capabilities of degradable micromotors with versatile biomedical applications.Moreover,we discuss micromotors’efficacy in detecting and destroying environmental pollutants.Finally,we address the limitations and future research directions of degradable metallic micromotors.

Effects of Iron-zinc Combined Application on Yield and Quality of Tobacco

[Objective] This study aimed to improve the yield and quality of tobacco. [Method] Different proportion combinations of zinc sulfate and iron sulfate were applied to Jiyan 9, and its agronomic traits, field natural incidence, economic characters and chemical composition were compared among different treatments. [Result] Iron-zinc combined application improved the yield and quality of tobacco. Among all the treatments, Treatment 2 （FeSO4 15 kg/hm2 ＋ ZnSO4 10 kg/hm2） and Treatment 5 （FeSO4 15 kg/hm2 ＋ ZnSO4 15 kg/hm2） were the best. [Conclusion] This study will provide a theoretical basis for the improvement of yield and quality of tobacco.

Sulfidation roasting of zinc leaching residue with pyrite for recovery of zinc and iron

Zinc leaching residue(ZLR) contains high content of valuable metals such as zinc and iron. However, zinc and iron mainly exist in the form of zinc ferrite, which are difficult to separate and recover. This study proposed a new process involving sulfidation roasting, magnetic separation and flotation to recover zinc and iron in ZLR. Through sulfidation roasting of ZLR with pyrite, zinc and iron were converted into ZnS and Fe3 O4. The effects of pyrite dosage, roasting temperature and roasting time on the sulfidation of zinc in ZLR were investigated. The results showed that the sulfidation percentage of zinc reached 91.8% under the optimum condition. Besides, it was found that ball-milling was favorable for the separation and recovery of zinc and iron in sulfidation products. After ball-milling pretreatment, iron and zinc were enriched from sulfidation products by magnetic separation and flotation. The grade of iron in magnetic concentrates was 52.3% and the grade of zinc in flotation concentrates was 31.7%, which realized the recovery of resources.

Effect of dephytinization on bioavailability of iron,calcium and zinc from infant cereals assessed in the Caco-2 cell model

AIM： To test the effect of the dephytinization of three different commercial infant cereals on iron, calcium, and zinc bioavailability by estimating the uptake, retention, and transport by Caco-2 cells. METHODS： Both dephytinized （by adding an exogenous phytase） and non-dephytinized infant cereals were digested using an in vitro digestion protocol adapted to the gastrointestinal conditions of infants younger than 6 too. Mineral cell retention, transport, and uptake from infant cereals were measured using the soluble fraction of the simulated digestion and the Caco-2 cells. RESULTS： Dephytinization of infant cereals significantly increased （P 〈 0.05） the cell uptake efficiency （from 0.66%-6.05% to 3.93%-13%）, retention （from 6.04%-16.68% to 14.75%-20.14%） and transport efficiency （from 0.14%-2.21% to 1.47%-6.02%）, of iron, and the uptake efficiency （from 5.0%-35.4% to 7.3%-41.6%） and retention （from 4.05%-20.53% to 14.45%-61.3%） of zinc, whereas calcium only cell uptake showed a significant increase （P 〈 0.05） after removing phytate from most of the samples analyzed. A positive relationship （P 〈 0.05） between mineral solubility and the cell uptake and transport efficiencies was observed. CONCLUSION： Removing phytate from infant cereals had a beneficial effect on iron and zinc bioavailability when infant cereals were reconstituted with water. Since in developing countries cereal-based complementary foods for infants are usually consumed mixed with water, exogenous phytase additions could improve the nutritional value of this weaning food.

Effects of Iron and Zinc Fertilizers on Antioxidant Activity of PearJujube in Loess Hilly Region

With eight-year-old pear-jujube trees with uniform and good growth as the research object,different concentrations of iron and zinc fertilizers were sprayed to the leaves,and the changes in the contents of vitamin C,total flavonoids,enzyme,as well as the removal rates of hydroxyl radicals,1,1-diphenyl-2-trinitrophenylhydrazine( DPPH) and hydrogen peroxide by polyphenols in pear-jujube were studied,so as to explore the effects of iron and zinc fertilizers on antioxidant activity of pear-jujube in loess hilly region. The results showed that different treatments affected the content of vitamin C and significantly increased the content of total flavonoids in pear-jujube. In the treatment of 0. 6%Fe SO_4+ 0. 3% Zn SO_4( L3),the contents of vitamin C and total flavonoids were both highest,2. 86 mg/g and 3. 02 mg/g,21. 8% and105. 4% higher than CK( P < 0. 05). Different fertilization treatments effectively reduced the activities of ascorbate oxidase and polyphenol oxidase in pear-jujube. The activity of ascorbate oxidase was lowest in the treatment of 0. 6% Fe SO_4+ 0. 3% Zn SO_4( oxidized ascorbic acid0. 069 mg/( g·min) FW,75. 1% lower than CK); and the activity of polyphenol oxidase was lowest in the L3 treatment( oxidized ascorbic acid 0. 146 mg/( g·min) FW,42. 0% lower than CK). Polyphenols of pear-jujube could effectively remove hydroxyl radicals,DPPH· and hydrogen peroxide. This was more significant in L3 treatment,of which the antioxidant activity was the best.

QTL underlying iron and zinc toxicity tolerances at seedling stage revealed by two sets of reciprocal introgression populations of rice(Oryza sativa L.)

Iron and zinc are two trace elements that are essential for rice. But they are toxic at higher concentrations, leading to severe rice yield losses especially in acid soils and inland valleys. In this study, two reciprocal introgression line(IL) populations sharing the same parents were used with high-density SNP bin markers to identify QTL tolerant to iron and zinc toxicities. The results indicated that the japonica variety 02,428 had stronger tolerance to iron and zinc toxicities than the indica variety Minghui 63. Nine and ten QTL contributing to iron and zinc toxicity tolerances,respectively, were identified in the two IL populations. The favorable alleles of most QTL came from 02,428. Among them, q FRRDW2, q ZRRDW3, and q FRSDW11 appeared to be independent of genetic background. The region C11S49–C11S60 on chromosome 11 harbored QTL affecting multiple iron and zinc toxicity tolerance-related traits, indicating partial genetic overlap between the two toxicity tolerances. Our results provide essential information and materials for developing excellent rice cultivars with iron and/or zinc tolerance by marker-assisted selection(MAS).

Effects of Copper and Manganese on Hemocyte Apoptosis and Antagonism of Iron and Zinc in Oreochromis niloticus

This study aimed to investigate the effects of copper and manganese on hemocyte apoptosis and the antagonism of iron and zinc in Oreochromis niloticus The heavy metal contents in fish blood and feed were determined by atomic absorption spectrophotometry, and the hemocyte apoptosis was determined by flow cytometry. A total of 360 tilapias were selected, and they were divided randomly and evenly into 12 groups. In the challenge groups, the tilapias were fed with con stant-level copper sulfate（0, 200 mg/kg） and manganese sulfate（0, 120 mg/kg）; in the antagonism groups, the tilapias were fed with constant-level zinc sulfate（20320 mg/kg） and iron sulfate（150, 350 mg/kg）. After 20-week aquaculture, the hemocyte apoptosis rates in the copper and manganese groups were significantly increased; with the increased addition levels of iron and zinc, the hemocyte apopto sis rates in the iron and zinc groups were significantly reduced, but they were stil higher than that in the control group. In conclusion, excessive copper and manganese can cause apoptosis in hemocytes of O. niloticus. However, the toxic effects of copper and manganese can be antagonized by iron and zinc.

Fundamental study on utilization of tin and zinc-bearing iron concentrate by selective chlorination

The feasibility and technologies of comprehensive recovery of tin, zinc, arsenic and iron from the complex iron ores by selective chlorination roasting were studied by thermodynamic analysis and roasting experiments. Investigation shows that the product pellets with the compression strength of 2625N/P, the tumble index of 97.26%, the abrasion index of 1.35%, tin, arsenic and zinc residue of 0.043%, 0.046% and 0.058% respectively can be achieved if balling a concentrate containing 0.39% tin, 0.40% arsenic and 0.28% with addition of 8% coke breeze and 0.5% CaCl2 and roasting the pellets at 10601080℃ for 40min. The volatilization of tin, arsenic and zinc is 91.75%, 93.42% and 81.12% respectively. The performances of the product pellets are able to meet the requirements of blast furnace ironmaking.

Sulfuric acid leaching of high iron-bearing zinc calcine

Sulfuric acid leaching of high iron-bearing zinc calcine was investigated to assess the effects of sulfuric acid concentration, liquid-to-solid ratio, leaching time, leaching temperature, and the stirring speed on the leaching rates of zinc and iron. The results showed that the sulfuric acid concentration, liquid-to-solid ratio, leaching time, and leaching temperature strongly influenced the leaching of zinc and iron, whereas stirring speed had little influence. Zinc was mainly leached and the leaching rate of iron was low when the sulfuric acid concentration was less than 100 g/L. At sulfuric acid concentrations higher than 100 g/L, the leaching rate of iron increased quickly with increasing sulfuric acid concentration. This behavior is attributed to iron-bearing minerals such as zinc ferrite in zinc calcine dissolving at high temperatures and high sulfuric acid concentrations but not at low temperatures and low sulfuric acid concentrations.

Intra-population genetic variance for grain iron and zinc contents and agronomic traits in pearl millet

Crop biofortification is a sustainable approach for fighting micronutrient malnutrition in the world. The estimation of variance components in genetically broad-based populations provides information about their genetic architecture, allowing the design of an appropriate biofortification breeding method for cross-pollinated crops such as pearl millet. The objective of this study was to estimate intra-population genetic variance using self(S1) and half-sib(HS) progenies in two populations, AIMP92901 and ICMR312. Field trials were evaluated in two contrasting seasons(2009 rainy and 2010 summer; otherwise called environments) in Alfisols at ICRISAT, Patancheru. Analyses of variance showed highly significant variation for S1 s and HS progenies, reflecting high within-population genetic variation for both micronutrients and other key traits. However, the HS showed narrow ranges and lower genetic variances than the S1 for all of the traits. The micronutrients were highly positively correlated in S1(r = 0.77 to 0.86; P < 0.01) and HS(r = 0.74 to 0.77; P < 0.01)progenies of both populations, implying concurrent genetic improvement for both micronutrients. The genetic variance component was different among populations for Fe and Zn contents across environments, with AIMP92901 showing a greater proportion of dominance and ICMR312 greater additive variance for these micronutrients. The estimates of variance(additive and dominance) were specific for each population, given their dependence on the additive and dominance effects of the segregating loci, which also differ among populations. The possible causes for such differences were discussed. The results showed that the expression of these micronutrients in pearl millet shows largely additive variance, so that breeding high-iron hybrids will require incorporation of these micronutrient traits into both parental lines.

Spectrophotometric Simultaneous Determination of Zinc(II), Manganese(II) and Iron(II) in Pharmaceutical Preparations Using OSC-PLS

This work reports the spectrophotometric simultaneous determination of zinc（Ⅱ）, manganese（Ⅱ） and iron（Ⅱ） in pharmaceutical preparation, using orthogonal signal correctionpartial least squares （OSC-PLS）. All the factors affecting on the sensitivity were optimized and the linear dynamic range for determination of these metals was found. The PLS modeling was used for the multivariate calibration of the spectrophotometric data. The OSC was used for preprocessing of data matrices and the prediction results of model. The experimental calibration matrix was designed by measuring the absorbance over the range 450-570 nm for 21 samples of 0.05-1.05, 0.10-1.10 and 0.05-1.05μg·mL^-1 of zinc（Ⅱ）, manganese（Ⅱ） and iron（Ⅱ）, respectively. The RMSEP for zinc（Ⅱ）, manganese（Ⅱ） and iron（Ⅱ） using OSC-PLS were 0.0164, 0.0132, 0.0146, respectively. The proposed method was successfully applied the determination of zinc（Ⅱ）, manganese（Ⅱ） and iron（Ⅱ） in pharmaceutical preparations.

Comprehensive recovery of Fe,Zn,Ag and In from high iron-bearing zinc calcine

A beneficiation-metallurgy combination process is developed to recover Zn, Fe and to enrich In, Ag from high iron-bearing zinc calcine based on our former researches. In gaseous reductive roasting process, the roasting conditions were tested by magnetic separation of roasted product. It is found that the V_(CO)(P_(CO)/(P_(CO+CO_2)) in roasting atmosphere should be maintained below 30% to avoid the generation of zinc iron solid solution(Fe_(0.85-x)Zn_xO), which can bring a decrease of iron recovery in magnetic separation. After roasting, acid leaching and multistage magnetic separation are carried out for the recovery of Zn, Fe and enrichment of Ag and In. About 90% of zinc is extracted and 83% of iron is recovered in the whole process. The Ag mainly enters the tailings with a recovery of 76%, the Ag grade increases from 0.12 g/t in raw materials to 1.18 g/t in the tailings. However, the In mainly enters the iron concentrations and the recovery reaches 86%. This process was proved to be technically feasible and may be a favorable option in the treatment of high iron-bearing zinc material with high Ag or In content.

Concurrent repletion of iron and zinc reduces intestinal oxidative damage in iron- and zinc-deficient rats

AIM： To understand the interactions between iron and zinc during absorption in iron- and zinc-deficient rats, and their consequences on intestinal oxidant-antioxidant balance. METHODS： Twenty-four weanling Wistar-Kyoto rats fed an iron- and zinc-deficient diet （〈 6.5 mg Fe and 4.0 mg Zn/kg diet） for 4 wk were randomly divided into three groups （n = 8, each） and orally gavaged with 4 mg iron, 3.3 mg zinc, or 4 mg iron ＋ 3.3 mg zinc for 2 wk. At the last day of repletion, 3 h before the animals were sacrificed, they received either 37 mBq of SSFe or ^65Zn, to study their localization in the intestine, using microautoradiography. Hemoglobin, iron and zinc content in plasma and liver were measured as indicators of iron and zinc status. Duodenal sections were used for immunochemical staining of ferritin and metallothionein. Duodenal homogenates （mitochondrial and cytosolic fractions）, were used to assess aconitase activity, oxidative stress, functional integrity and the response of antioxidant enzymes. RESULTS： Concurrent repletion of iron- and zinc-deficient rats showed reduced localization of these minerals compared to rats that were teated with iron or zinc alone; these data provide evidence for antagonistic interactions. This resulted in reduced formation of lipid and protein oxidation products and better functional integrity of the intestinal mucosa. Further, combined repletion lowered iron-associated aconitase activity and ferritin expression, but significantly elevated metallothionein and glutathione levels in the intestinal mucosa. The mechanism of interactions during combined supplementation and its subsequent effects appeared to be due to through modulation of cytosolic aconitase, which in turn influenced the labile iron pool and metallothionein levels, and hence reduced intestinal oxidative damage.CONCLUSION： Concurrent administration of iron and zinc corrects iron and zinc deficiency, and also reduces the intestinal oxidative damage associated with iron supplementation.

Iron, Zinc, and Copper Malnutrition among Primary School Children in Lagos, Niagara

This study assessed the iron, zinc and copper status of primary school-attending children in Lagos. A sample of 200 primary School-attending children was randomly selected using a stratified 2 – stage sampling technique. Data was collected in the 2 major seasons in Nigeria;Dry and Rainy seasons using dietary intake (24 hr dietary recall protocol) venipuncture blood samples, and a self-administered questionnaire. The data were analyzed using descriptive and inferential statistics. Among ages 5 - 8 years, the main dietary intake for iron was 10.66 ± 12.44 mg/d (106% of DRI), for zinc, 7.30 ± 7.39 mg/d (92% of DRI) and for copper, 1.55 ± 1.31 mg/d (390% of DRI). For ages 9 - 13 yrs, the mean intake of micronutrients showed that iron was 11.03 ± 12.72 mg/d (138% of DRI), 3inc was 8.44 ± 7.7 mg/d (105% of DRI) and copper was 3.75 ± 15.17 mg/d (536% of DRI). Biochemical results indicated that 19.8% of the subjects had inadequate serum iron, 21% and 32.1% were zinc and copper deficient respectively prevalence of anemia was 38.1% while iron deficiency anemia was 13.06% and iron deficiency was 34.6%. Dietary intakes did not provide right amounts of micronutrients to meet body requirements. There is the need to formulate and implement nutrition education programs to correct micronutrient deficiency among primary school-attending children in Lagos, Nigeria.

Iron and Zinc Serum Levels in Young Adult Cameroonians after Supplementation in Poor Vitamin A and Controlled Diets

Iron, zinc and vitamin A deficiencies co-exist in Cameroon in all age groups. However, natural sources of vitamin A are available and could be used to meet the need of the whole population in association with iron and zinc supplementation. This study aims at assessing the serum levels of zinc and iron after 11 days of supplementation. The study enrolled 26 men 08-33 years）, distributed into five groups. From the first day, they were supplemented with 20 mg of zinc and iron, taken each alone, both either together or at two different times. The five last days, participants were put on free vitamin A diets. Serums were obtained at day l, day 5 and day 11 for Zn and Fe levels determination by atomic absorption spectrophotometry. The highest serum iron and zinc concentrations were observed in groups either supplemented with zinc or with iron given alone. In those two groups, serum Zn concentrations increased from 0.69 μg/mL ±0.02μg/mL to 0.95 μg/mL ± 0.13 μg/mL （group 2）, from 0.48 μg/mL ± 0.06 μg/mL to 0.97 μg/mL ± 0.11 μg/mL （group 3）; and serum Fe concentrations from 1.49 μg/mL ± 0.54 μg/mL to 3.49 μg/mL ± 1.01 μg/mL （group 2）; and from 1.42 μg/mL ± 0.45 μg/mL to 3.41 μg/mL ± 0.81 μg/mL （group 3）, respectively. Supplementation with Fe or Zn alone increased both Fe and Zn serum levels of participants. Serum levels of iron and zinc when given together or at different time were not significantly different. Further studies on a larger population are necessary to confirm that supplementation with zinc or with iron alone could raise both zinc and iron levels in serum simultaneously.