|Year : 2020 | Volume
| Issue : 1 | Page : 16-20
Zinc status of under-five children in selected urban and rural settings in Enugu State, Nigeria
Joshua I Ugwu1, Ikechukwu E Ezeagu2, Madu D Ibegbu2, Nonso C Ejiofor2, Chigozie P Okorie2
1 Department of Biochemistry, Renaissance University, Ugbawka, Enugu, Nigeria
2 Department of Medical Biochemistry, University of Nigeria, Enugu Campus, Enugu, Nigeria
|Date of Submission||01-Jun-2019|
|Date of Decision||17-Feb-2020|
|Date of Acceptance||24-Feb-2020|
|Date of Web Publication||03-Apr-2020|
Prof. Ikechukwu E Ezeagu
Food Composition Analysis & Public Health Nutrition Research Group, Department of Medical Biochemistry, University of Nigeria, Enugu Campus, Enugu.
Source of Support: None, Conflict of Interest: None
Background: High incidence of zinc (Zn) deficiency, especially among under-five children, is widely reported in developing countries including Nigeria. Objective: The aim of this study was to provide data on the Zn status of under-five children in Enugu State. Materials and Methods: This was a descriptive cross-sectional study of under-five children in Enugu South (urban) and Nkanu West (rural) local government areas (LGAs). A total of 409 children (244 urban and 165 rural) were enrolled in the study. Non-fasting venous blood (2 mL) was obtained from a total of 409 under-five children and the serum Zn was determined by using an atomic absorption spectrophotometer. Serum Zn level of < 70 µg/L was defined as Zn deficiency. Results: Although 222 (54%) of the children were adequate, 187 (46%) were deficient in Zn. Of the 165 children from the rural area, 73 (44%) were deficient in Zn, whereas in urban area, of 244 children, 112 (46%) were deficient in Zn (<70 µg/dL). The mean serum Zn level (73.86 ± 15.99 µg/dL) of the urban under-five children was significantly (P = 0.009) higher than that of the rural children (68.25 ± 9.04). In the rural setting, higher incidence of Zn deficiency occurred among the male subjects (32 [52.8%]) compared to the female subjects (35 [37.6%]) although the difference was not statistically significant (P = 0.08). Conclusion: The results indicate a high incidence of Zn deficiency in the studied population, which seems higher in the rural than in the urban LGA. Nutrition educational programs, intake of food rich in Zn and supplements should be promoted to improve Zn intake especially in infant and young child feeding practices.
Keywords: Deficiency, Nigeria, nutrition, under-five children, zinc
|How to cite this article:|
Ugwu JI, Ezeagu IE, Ibegbu MD, Ejiofor NC, Okorie CP. Zinc status of under-five children in selected urban and rural settings in Enugu State, Nigeria. Int J Med Health Dev 2020;25:16-20
|How to cite this URL:|
Ugwu JI, Ezeagu IE, Ibegbu MD, Ejiofor NC, Okorie CP. Zinc status of under-five children in selected urban and rural settings in Enugu State, Nigeria. Int J Med Health Dev [serial online] 2020 [cited 2022 Oct 6];25:16-20. Available from: https://www.ijmhdev.com/text.asp?2020/25/1/16/281882
| Introduction|| |
Zinc (Zn) is an essential micronutrient that is needed in small amounts every day for good health. Zn is found in cells throughout the body and is needed for the defensive (immune) system to work properly. It plays a role in cell division, cell growth, wound healing, and breakdown of carbohydrates. During pregnancy, infancy, and childhood, the body needs Zn to grow and develop properly. Zn is also involved in numerous aspects of cellular metabolism. It is present in the brain and contributes to its structure and its function and evidence links mild-to-moderate Zn deficiency with children’s cognitive development.
Zn deficiency is characterized by growth retardation, loss of appetite, and impaired immune functions. In more severe cases, Zn deficiency causes hair loss, diarrhea, delayed sexual maturation, impotence, hypogonadism in males, eye and skin lesions, and delayed healing of wounds. Zn deficiency is a predisposing risk factor for diarrhea and pneumonia, which are common causes of death in children <5 years old. Zn supplementation has been shown to help reduce the duration and severity of diarrhea and pneumonia., Studies by Asuquo et al. further showed that Zn supplementation can halt the course of diarrhea disease, in Nigeria. In view of the public health significance of Zn deficiency, this study, therefore, aimed to evaluate the Zn status of under-five (u-5) children in both urban and rural settings in Enugu State, Nigeria.
| Materials and Methods|| |
This was a descriptive cross-sectional study of nursery school children (<5 years) in Enugu South (urban) and Nkanu West (Rural) local government areas (LGAs) of Enugu State, Nigeria.
The sample size was calculated as follows:
where Ss is the sample size, z is the z score at 95% confidence limit (1.96), p is the (estimated) proportion of the population, which has the attribute in question, and c is confidence level.
The values for population >10,000 and <2,000 are given as follows:
z = 1.96, c = 0.05, P = 0.5,
Approximately 10% of the sample size was added to make up for nonrespondents, which gave a total of 422.
A multistage random sampling technique was used in the selection of u-5 children whose caregivers gave their consent for the study. First stage, 17 LGAs, Enugu South and Nkanu West, representing urban and rural settings, respectively, were selected using a simple random technique (balloting). Second stage, there were 13 and 12 wards in Enugu South and Nkanu West, respectively. Eight wards were selected using a simple random technique (balloting) in each of the two LGAs. Third stage, in each of the wards, a school was selected also by a simple random technique by balloting. Fourth stage, in each school that had more than 25 respondents, purposive sampling technique was used to select the u-5 pupils whose caregivers gave their consent for the study. A total sample size of 412 u-5 children was enlisted: 244 (116 males and 128 females) from Enugu South LGA, the urban setting, whereas 165 (72 males and 93 females) were enrolled from Nkanu West LGA, the rural setting; the disparity in the selection of the population size was based on recurrent recruitments.
Only u-5 children (aged 36–60 months) attending registered nursery schools in Enugu State were involved in the study.
Children with high temperature ascertained with the aid of clinical thermometer and those their caregivers refused to sign the consent form were excluded from the study.
Ethical clearance was obtained from Enugu State Ministry of Health and from the University of Nigeria Teaching Hospital Ethical Committee. Written and signed informed consents were obtained from all parents or caregivers of u-5 children enrolled for the study.
Blood collection and analysis
Three of the enrolled children withdrew from the study due to illness. Therefore, 409 samples of non-fasting venous blood (2 mL) were collected from each subject with the assistance of a Board Certified Laboratory Scientist. Serum was separated by centrifuge and stored at 4°C until analysis. Sera were analyzed for Zn using thermal atomic absorption spectrophotometer. Zn level of <70 µg/L was defined as deficiency.,
| Results|| |
Considering the total (n = 409) u-5 children enrolled, 54% (224) were adequate (≥70 µg/dL) in Zn status, 46% (187) were deficient in Zn status. Among the Zn-deficient children, 36% (146) were marginally deficient (50–69 µg/dL) and only 10% (41) were severely deficient (<50 µg/dL).
A total of 114 children in Enugu South and 73 from Nkanu West were Zn deficient. The Zn status based on gender and location [Table 1] indicates that children with severe Zn deficiency were 10% (14) for urban and 16% (27) for rural settings (P = 0.009).
|Table 1: Frequency distribution of serum Zn status of U-5 children by gender and location|
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Children with serum Zn level considered marginal deficiency were 40% (100) in the urban and 28% (46) among the rural, whereas those having adequate serum Zn status (≥70 µg/dL) were 53% (130) and 56% (92) among the urban and rural dwellers, respectively [Table 1]. Higher incidence of marginal deficiency of Zn occurred among urban female u-5 children (40.6%) than among the rural counterpart (19.3%) [Table 1]. Male and female urban children recorded higher frequency of adequacy in Zn status than the rural children.
[Table 2] summarizes the serum Zn level of the u-5 children. Among the urban, serum Zn ranged from 35.05 to 108.64 µg/dL, with a mean of 73.86 ± 15.99 µg/dL. Children in the rural area recorded serum Zn levels ranging between 18.45 and 92.34 µg/dL, and mean of 68.25 ± 9.04 µg/dL. The results showed that serum Zn levels of the urban children were significantly higher (P = 0.009) than that of the rural children [Table 2] and the median value showed a preponderance of marginal deficiency among the rural u-5 children. [Table 3] compares the gender difference in the serum Zn status of the u-5 children enrolled in this study. Of the 188 enrolled male children, 92 (48.9%) were deficient in Zn and of the 221 female subjects, 95 (42.9%) were Zn deficient. Sixteen male subjects (8.5%) and 25 female subjects (11.3%) were severely deficient in Zn. The Zn status of the children was not significant (P > 0.05) on gender bases.
|Table 2: Summary of serum zinc level of U-5 children in Enugu State (µg/dL)|
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|Table 3: Comparative analysis of serum zinc status of male and female under-5 children|
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| Discussion|| |
Results from this study showed that 187 (45.7%) of the 409 u-5 children enrolled in this study were deficient in Zn. Zn deficiency is one of the most common micronutrient deficiencies in children under the age of 5 years in Nigeria and developing countries. Children in Enugu South (urban setting) recorded higher serum Zn levels compared to those in the Nkanu West LGA (rural setting). Demographic profile of rural settings in Nigeria is generally characterized with poverty and malnutrition and low economic status, which can be the reason for the deficiency observed in this study. Animal food sources that are rich in Zn are expensive and not affordable to most rural dwellers. Similarly, Abah et al. reported a higher prevalence of 99% deficiency among a rural community in North Central Nigeria, with children from lower socioeconomic class having significantly lower serum Zn level compared with those from the upper classes. No significant gender-based differences were observed in Zn status among u-5 children in both urban and rural settings. Higher incidence of Zn deficiency occurred among the males (52.8%) compared to the females (37.6%) in the rural setting. Similarly, Jaryum et al. and Igbokwe et al. reported incidence of Zn deficiency higher among male than female subjects.
Although Caval et al. reported a prevalence of low plasma Zn among males, others reported no significant difference between genders. Gender differences within rural and urban children in this study may just be cases of dietary intakes at household levels or worm infections rather than physiological.
A study of 61 preschool children in Sokoto, Nigeria reported 37.7% incidence of severe serum Zn (<50 µg/dL) levels, which is closely similar to the 41% obtained in this study. Onyemaobi and Onimawo using 65 µg/dL as the benchmark reported a 41.5% Zn deficiency among u-5 children in Imo State with significantly higher deficiency among rural children, and comparable to the results obtained in this study. Similarly, Ugwuja et al. reported lower serum Zn level for malnourished children compared to that of the well-nourished in Jos Nigeria.
This study and other reports are indication that Zn deficiency may be widespread in Nigeria.
Nigeria is among the countries with a high risk of Zn deficiency based on the prevalence of stunting among u-5 children. According to the 2001–2003 Nigeria Food Consumption and Nutrition Survey, the national prevalence of Zn deficiency among u-5’s was 21%. According to 2013 Nigeria Demographic and Health Survey (NDHS), 37% of u-5 children are stunted, and stunting in children is considered as an indirect indicator of Zn nutritional status. Over dependence on vegetarian diets with fewer intakes of animal foods contributes to the high prevalence of Zn deficiency in developing countries, which can also lead to stunting.
Most children living in the rural communities are constantly faced with malnutrition, especially of Zn, which reduces the number of B- and T-lymphocytes and CD34+ lymphocytes in particular. It was reported in Kano that the serum Zn level of malnourished children was lower than well-nourished ones. Malnutrition coupled with poverty and ignorance on the importance of food group diversity for the health and growth of young children may contribute to reduce Zn status levels. Incidence of parasitic infections, such as helminthiasis and diarrhea, that are common in poor and developing countries, also result to increased Zn losses.
A low serum Zn concentration was shown to predict an increased risk of diarrhea among children and a risk factor for anemia in school-aged school children., Smian et al. observed that children with community-acquired pneumonia had imbalance of Zn and Cu, and the severity of this elements could be a contributing factor to the pathophysiology of the disease. The children in this research if not treated with Zn supplements may fall victims of pneumonia or other diseases associated with Zn deficiencies.
The deficient children in this work will be prone to stunting, less interagency, psychomotor, and neurobehavioral problems if allowed to persist. Infantile and early childhood Zn deficiency has been associated with stunted growth and with learning, psychomotor, and neurobehavioral problems., Improved linear growth in stunted children has been strongly associated with Zn status. Studies conducted among Beninese and Nigerian u-5 children showed that prevalence of low plasma Zn was directly related to inadequate dietary intakes and the high incidence of stunting., Children with good Zn status have a higher coping capacity in terms of immune response to infection than those with poor Zn status.
Unlike vitamin A and iodine, there are no programs or policy initiatives in place to specifically improve the Zn intakes of human populations. This is true with respect to improving the Zn supply in foods. A daily intake of Zn is required to maintain a steady state because the body has no specialized Zn storage system. Phytate is common in plant foods and can modulate zinc absorption by chelating to zinc in the digestive system and thus inhibit its absorption from the diet. Excess losses of zinc during diarrhoea may also contribute to Zn deficiencies. Dietary sources of Zn are lean red meat, whole-grain cereals, pulses, and legumes, which provide the highest concentrations of Zn 25–50 mg/kg raw weight. Processed cereals with low extraction rates, polished rice, and lean meat or meat with high-fat content have moderate Zn content of 10–25 mg/kg. Fish, roots and tubers, green leafy vegetables, and fruits are only modest sources of Zn <10 mg/kg. Children in developing countries are often Zn deficient and therefore Zn supplementation could be timely public health intervention.
| Conclusion|| |
The prevalence of serum Zn deficiency of u-5 children in this study is 45%. The serum Zn levels of the children living in the rural settings were also lower compared to those of the urban settings. The risk of Zn deficiency is high enough and calls for a national intervention program through public health nutrition interventions to improve the Zn status.
We wish to acknowledge the technical support received from the Network on Behavioral Research for Child Survival in Nigeria (NETBRECSIN). We also gratefully acknowledge the logistic support from Mr. A. Ezeugwu and Mr. S. C. Igboekwu both of the Department of Disease Surveillance of Nkanu West and Enugu South Ministries of Health, respectively. The support of the traditional rulers of Agbani and the caregivers that volunteered to be part of this research work are highly appreciated. Thanks are also due to the head teachers of Igbariam and Achara Layout Nursery Schools. Our sincere thanks are also extended to the parish priests of St. Peter’s Catholic Church, Garki, St. Paul’s Church, Ozalla, and St. Anthony’s Church, Obe, for their logistic support during the sample collection.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2], [Table 3]