Nigerian Journal of Basic and Clinical Sciences

ORIGINAL ARTICLE
Year
: 2021  |  Volume : 18  |  Issue : 1  |  Page : 18--23

Dietary pattern of undernourished children and their Vitamin A status in institute of child health Ahmadu Bello University Teaching Hospital Zaria


Sakinatu Mahadi Abdullahi1, Yakubu Mela Alhassan1, Mairo Adamu Bugaje1, Shehu Abubakar Akuyam2,  
1 Department of Paediatrics, Ahmadu Bello University Teaching Hospital, Zaria, Kaduna, Nigeria
2 Department of Chemical Pathology, Ahmadu Bello University Teaching Hospital, Zaria, Kaduna, Nigeria

Correspondence Address:
Dr. Sakinatu Mahadi Abdullahi
Department of Paediatrics, Ahmadu Bello University Teaching Hospital, Shika Zaria, Kaduna
Nigeria

Abstract

Context: Vitamin A deficiency (VAD) affects an estimated six million pre school children in Nigeria and 20 million in Africa. When associated with severe undernutrition, it increases both morbidity and mortality of under five children. Aims: The study was aimed to determine the dietary pattern and its relationship with Vitamin A levels in undernourished children and controls in Institute of Child Health (ICH), Ahmadu Bello University Teaching Hospital Zaria. Settings and Design: This was a case–control, hospital based descriptive study carried out at the ICH Banzazzau, Zaria. Materials and Methods: Systematic sampling method was adopted to select undernourished children aged 6–59 months for the study. A semi-quantitative food frequency questionnaire was developed following the International Vitamin A Consultative Group guidelines for dietary assessment of Vitamin A intake. The questionnaire consisted of a list of 22 food items obtained during survey from local markets. Serum Vitamin A level was analysed by high performance liquid chromatography. The frequency of values below a cut off, usually taken as 0.70 μmol/L (20 μg/dl) for low and 0.35 μmol/L (10 μg/dl) for deficiency. Statistical analysis: The data were analysed using the Statistical Package for the Social Sciences version 20.0. Results: The prevalence of low serum Vitamin A level (10–<20 μg/dl) in this study among the cases is 16.7%, with the highest prevalence of 15.9% seen in severe wasting. However, the prevalence of cases with deficient serum Vitamin A (<10 μg/dl) was 4.5% in which severe wasting accounted for all the cases. Interestingly, the prevalence of low serum Vitamin A levels among the controls was also found to be 16.7%, and there was no VAD among the control groups. About 20% of children in Zaria (controls) were moderate to high risk of poor intake, while 37.3% were at low risk and 42.7% had satisfactory intake of Vitamin A rich foods. Among the malnourished patients, 53.4% were at moderate to high risk of poor intake, while 21.3% were at low risk and 25.3% had satisfactory intake of Vitamin A rich foods. Conclusion: This study simply demonstrated low intake of Vitamin A among undernourished children in Zaria.



How to cite this article:
Abdullahi SM, Alhassan YM, Bugaje MA, Akuyam SA. Dietary pattern of undernourished children and their Vitamin A status in institute of child health Ahmadu Bello University Teaching Hospital Zaria.Niger J Basic Clin Sci 2021;18:18-23


How to cite this URL:
Abdullahi SM, Alhassan YM, Bugaje MA, Akuyam SA. Dietary pattern of undernourished children and their Vitamin A status in institute of child health Ahmadu Bello University Teaching Hospital Zaria. Niger J Basic Clin Sci [serial online] 2021 [cited 2021 Nov 28 ];18:18-23
Available from: https://www.njbcs.net/text.asp?2021/18/1/18/315404


Full Text



 Introduction



The most completely understood function of Vitamin A at molecular level is the role in preventing abnormal dark adaptation or 'night blindness'. Vitamin A is necessary for normal mucociliary function of epithelial lining of the gastrointestinal and respiratory tracts, but changes are more readily observed in the conjunctiva.[1],[2]

It has regulatory influence on cell differentiation, affecting such diverse functions as spermatogenesis, egg hatching, implantation, organogenesis, pregnancy maintenance and postnatal organ maturation.[2]

It is also important in maintaining the lymphoid pool. Both cell-mediated and antibody-mediated responses may be adversely affected by Vitamin A deficiency (VAD), with T-cell-dependent responses being more strongly affected.[2],[3]

Natural and synthetic compounds with vitamin A-like activity are known to have anticancer properties by affecting cellular differentiation, especially epithelial tissues.[2]

VAD is a major public health problem in many developing countries of the world[1] including Nigeria.[2],[3] It is not only a cause of blindness but also a cause of childhood morbidity and mortality.[4],[5],[6] It is well established that malnourished children have low serum Vitamin A levels mainly due to inadequate intake of diet rich in Vitamin A.

 Materials and Methods



Study settings

The study was carried out at the Institute of Child Health (ICH) Banzazzau, Zaria. The institute serves the community/children mainly from Zaria and its environs and is the Primary Health Care outlet of Ahmadu Bello University Teaching Hospital (ABUTH), Zaria. The ICH offers outpatient service and receives an average of 200 patients in a day.

Study design

This was a case–control hospital-based descriptive study, designed to evaluate the dietary habits and serum Vitamin A levels among malnourished children and controls in Zaria.

Study population

The study population consisted of consecutive malnourished children between the ages of 6–59 months who presented to ICH. The World Health Organization (WHO) Z-score classification was used in the classification of malnutrition in this study into mild, moderate and severe malnutrition using weight, height/length, mid-upper arm circumference and presence or absence of oedema, socioeconomic and educational statuses of the parents were considered. Age-matched well-malnourished children who presented to the ICH with clinical features of malaria, acute respiratory infections (ARIs), acute diarrhoeal diseases among others were enrolled as controls. Informed consent was duly obtained from each child's parents or care givers before recruitment in the study.

Sampling technique

The respondents were selected consecutively using convenient sampling technique.

Study instruments

Relevant data using a pro forma which included patient's name, age, sex, tribes and dietary history with particular emphasis on frequency of ingestion of Vitamin A-rich foods were collected from all children enrolled for the study. An initial market survey was carried out on a market day as part of pre-survey visit. This is necessary for preparing a dietary questionnaire for the community. Some of the pro Vitamin A food items sold at the market were palm oil, tomatoes, pepper, green leafy vegetables and pawpaw. A semiquantitative food frequency questionnaire was developed following the International Vitamin A Consultative Group guidelines for dietary assessment of Vitamin A intake.[7] The questionnaire consisted of a list of 22 food items obtained during market survey. To facilitate the effort to obtain semiquantitative, recall information portion sizes of these food items are illustrated with the coloured photographs, each picture depicting the three portion sizes (small, medium and large).[7] There were column and rows of the questionnaire. The column was formed by four food groups: high (H), satisfactory (S), medium (M) and low (L) according to Vitamin A content of these food items. The rows were formed by three portion sizes: small, medium and large. For the four food groups the weighting factors were 5, 4, 2 and 1, respectively, for H, S, M and L. For each portion size, the weighting factors are 1, 2 and 3 for small, medium and large, respectively. A table including the four food groups with their respective three portion sizes were constructed in [Table 1].[7] The usual pattern of food consumption (UPF) score was determined by summing scores in the weekly food frequency component of the questionnaire. UPF was adjusted for the currently breastfed children. [Table 2] provides the scores to be added to the UPF. A UPF was, thus, the sum of scores obtained from the weekly food frequency component of the questionnaire plus scores that accounted for current breastfeeding. This was aimed at identifying populations at risk of inadequate Vitamin A. The assignment of risk category was based on the Food and Agricultural Organization/WHO-recommended dietary intake of preschool children of 350 retinol equivalent (RE) daily, that is, (7 × 50), where 50 is the small portion size. This was equivalent to 2450 RE weekly (350 × 7). A child with UPF of >49 would in theory meet the recommended dietary intake and be at low risk. It was assumed that this amount will supply adequate Vitamin A without depleting body store.[7] It was also assumed that intakes less than two-thirds of the recommended intake cause depletion and would place a child at risk. A UPF of 35 (35 × 50 = 1750 RE) is considered a high-risk category. Thus, the relative level of risk categories based on UPF scores was as follows: score > 63 = safe level, score 49–63 = low risk, core 35–49 = moderate risk and score < 35 = high risk. History of preceding illnesses within two weeks such as measles, diarrhoeal diseases and ARIs which were risk factors for VAD was recorded. Anthropometric measurements were conducted on each participant and documented. A detailed physical examination was conducted to check for features of undernutrition such as oedema, skin and hair changes.[4],[5]{Table 1}{Table 2}

Sample size determination

The minimum sample size was determined using the formular for two groups. The prevalence of serum Vitamin A in malnourished under-five children from previous study.

The sample size was determined using the following formula:[8]]

[INLINE:1]

Where

S = sample size

α = Level of significance = 0.05

1−β = power of the study 80%

[INSIDE:1]= standard deviation (SD) for required confidence interval = 1.96

P1 = Proportion or prevalence of cases of VAD in malnourished patients 52% = 0.52

P2 = Proportion of control 48% =0.48

Z1 − β = SD for required power = 0.28

[INLINE:2]

Attrition (20%) of 62.50 = 3.15

62.50 + 3.15 = 65.65 = 66 cases

Controls were also 66

Therefore, the overall sample size = 132.

Ethical approval

Approval for the study was obtained from the ethical committee of ABUTH Zaria.

Data collection

Each questionnaire was administered by an interviewer trained for the purpose. Ethical conduct guiding a research such as respecting the autonomy of the participants and confidentiality were upheld.

Biochemical tests

Blood collection and processing

Four millilitres of venous blood were collected into a plain bottle from selected patients and was wrapped in a black lylon, so that retinol will not be denatured by light and the sera were separated by centrifugation at 1000 g for 10 min at the ICH laboratory by the investigator. Serum was taken with Pasteur pipette into 2 ml tube, re-labelled and were wrapped in a black lylon. The samples were immediately placed in a cooler containing ice cubes by the investigator and transported by road to the Chemical Pathology Laboratory, ABUTH Zaria where they were frozen at −20°C until analysis. The samples were analysed for serum Vitamin A levels at Chemical Pathology Laboratory, University College Hospital, Ibadan. All these were done by the investigator except sample analysis, which was done by the laboratory scientists.

Serum Vitamin A estimation

Serum Vitamin A levels were determined by high-performance liquid chromatography (HPLC, Shimadzu prominence, made in Japan and functional) using Bieri method.[9] The principle was that a given volume of serum or plasma was diluted with methanol, which denatures plasma proteins, and retinol was extracted with a suitable organic solvent which is hexane.

Procedure

One hundred microlitre (100 μl) of serum and 100 μl of the internal standard 0.6 μg retinyl acetate/ml (used as internal standards to correct for losses during extraction or during analysis) were transferred in a test tube. 100 μl of methanol was added to denature and precipitate proteins (essential for release of retinol from retinol – binding protein), and the sample was mixed. 200 μl of spectograde hexane was added and the contents were mixed vigorously but intermittently for 45 s on a vortex mixer and then centrifuged at 50,000 rpm for 3 min to ensure phase separation using a fixed head centrifuge, made from Japan and of bucket size. The upper hexane layer was transferred to another tube using a Pasteur pipette. The combined hexane extracts were then evaporated under a gentle stream of argon and the residue was re-dissolved in 50 μl of propan-2-ol. This was injected into the HPLC column specification with a 100 μl syringe for HPLC. Elution was carried out with methanol: water (95:5 v/v at a flow rate of 1.5 ml/min, monitored at 5 min. Retinol was quantitated by use of peak height ratios relative to an internal standard (retinyl acetate).[9]

HPLC method was considered in this study because of its high specificity and sensitivity.[10] HPLC is available to measure individually both retinol and retinyl esters. HPLC provides precise and accurate means of analysing serum Vitamin A. It offers a quick, automated and highly reproducible methods compared to other methods. Thus, this method was used to determine the serum Vitamin A levels among malnourished children as seen in ICH, ABUTH Zaria. Other biochemical methods for Vitamin A assay are ultraviolet absorption spectrophotometry methods are the least expensive to use but also least sensitive. Fluorimetric methods are sensitive, but the laboratory should be able to maintain conditions that avoid contamination from interfering fluorescing substances. HPLC is available to measure individually both retinol and retinyl esters. In contrast, spectrophotometric and fluorimetric techniques generally measure total Vitamin A. Calorimetric methods are not recommended because it is not as sensitive as the other methods.[10]

The limitation of measuring serum Vitamin A is that the profile obtained reflects a static situation and fails to capture the dynamics that may be occurring because of seasonal, ecologic, economic or other biologic factors.[10]

Another biochemical method is the plasma retinol binding protein (RBP) response test. Plasma RBP is determined by quantitative radial immunodiffusion or by enzyme linked immunosorbent assay.[11] The total body pool of Vitamin A can be determined by a new method called isotope dilution analysis.

Quality control procedure

The quality control procedure applied for estimation of Vitamin A using HPLC includes: The participants were adequately prepared before the collection of the blood sample which was followed by correct specimen collection, timely transportation and processing using a standard operational procedure, all the samples were ran in batches for each batch a quality control material is included, that is all the batches are ran alongside for quality control material using a standard operating procedure and following the analysis, all the test results were carefully calculated and reported.

Statistical analysis

Obtained data were compiled and analysed using Statistical Package for the Social Sciences version 20.0. Comparison of mean values was done using Student's t-test and level of significance was set at P < 0.05.

The prevalence of low serum Vitamin A level (10–<20 μg/dl) in this study among the cases is 16.7%. However, the prevalence of cases with deficient serum Vitamin A (<10 μg/dl) was 4.5%. Interestingly, the prevalence of low serum Vitamin A levels among the controls was also found to be 16.7% and there was no VAD among the control groups.

 Results



The demographic variables for both groups showed 26 (39.4%) were males and 40 (60.6%) were females with a male: female ratio of 1:1.5 among cases, while for the controls, 30 (45.5%) were males and 36 (54.5%) were females as shown in [Table 3]. Among the cases, all were wasted, out of which 13 (19.7%), 9 (13.6%) and 44 (66.7%) had mild, moderate and severe wasting. Similarly, all the cases were stunted with the severity ranging from mild, 11 (16.7%), moderate, 19 (28.8%) and severe, 36 (54.5%). All the participants enrolled on the control were well nourished and all their various anthropometric measurements largely within reference limit for age, sex and biographical environment.{Table 3}

The distribution of serum Vitamin A levels is shown in [Table 4]. Three (4.5%) and 11 (16.7%) cases with wasting had deficient and low serum Vitamin A levels as compared to 11 (16.7%) of controls with low serum Vitamin A levels and none was deficient in serum Vitamin A levels. Similarly, 3 (4.5%) and 11 (16.7%) of cases with wasting had deficient and low serum Vitamin A levels as compared to 11 (16.7%) of controls with low serum Vitamin A levels. The statistical analysis did not show significant difference (P = 0.492) between both wasting and controls and stunting and controls. Dietary information showed that all the children (cases and controls) were breastfed. The mean duration of breastfeeding for male cases was 9.30 ± 5.79 months and for females was 9.60 ± 7.36 months. One-week dietary recall showed that most widely consumed Vitamin A was carotenoids. Those food stuffs with high (>250 RE) pro-Vitamin A contents were palm oil prepared with soups, for example, are okro soup, stew or porridge (beans, yams) or with dark green leafy vegetables; 25 (18.9%) consumed eggs and only 12 (9%) consumed liver. The mean serum Vitamin A level for those on breast milk at the time of this study was 61.19 ± 11.39 μg/dl, while the mean for those on mixed diet and not on breast milk was 56.81 ± 13.48 μg/dl. This was statistically significant (P = 0.004, t = 2.851). Usual pattern of consumption of Vitamin A-rich foods (UPF) was based on addition of scores obtained weekly from consumption of these food stuffs for each child. [Table 5] shows the frequency distribution of risk assessment for UPF score and mean serum Vitamin A levels for each score. The mean serum Vitamin A for those in high risk and moderate risk for cases were low (58.11 ± 1.45 and 57.92 ± 1.38 μg/dl, respectively) and highest for the low risk category at (61.55 ± 8.51 μg/dl). For the controls, it also shows the same pattern except that the highest mean serum Vitamin A level of 64.49 ± 1.12 μg/dl was seen in the safe level category. There were statistically significant differences in the mean serum Vitamin A levels for different UPF scores between cases and controls (P = 0.0001, t = 9.139).{Table 4}{Table 5}

 Discussion



This study showed that VAD is a public health problem among malnourished children in Zaria. Eleven (16.7%) of both the cases and the controls had low levels (10–19 μg/dl) of serum Vitamin A during the rainy season when this study was carried out and so the absorption of Vitamin A is expected to be more than in the dry season. The dietary history of food consumption and availability reveals that this area has an abundance of Vitamin A-rich foods such as red palm oil, mango, green leafy vegetables and fish year-round which were taken averagely by cases and controls. The general availability and intake of Vitamin A-rich foods do not preclude the presence of VAD in this region. Other factors such as diarrhoeal disease and acute respiratory tract infections may be responsible for the deficiency state of Vitamin A.

This study has shown that all the 36 children in the 6–12 months age group were on breast milk at the time of the study and they had low mean serum Vitamin A levels. The mean duration of breast feeding for males and females among the cases were 9.30 ± 5.79 month and 9.60 ± 6.46 months, respectively. However, the mean duration of breast feeding for male and female controls was 10.13 ± 6.46 and 16.51 ± 88 months, respectively. There was, however, poor correlation between duration of breastfeeding and serum Vitamin A levels. It has been documented that breast milk contains readily absorbable preformed Vitamin A in amount protective against clinical VAD up to 4–6 months of life. Beyond this period, it may be inadequate to build body stores.[12] In the population studied, the Vitamin A requirements of the infants in all probability were not entirely covered by breast milk alone. This study has also shown that there was high prevalence of serum VAD in children between 13–24 months among the cases. This might be due to prolonged inadequate intake of Vitamin A-containing foods. The UPF was used to categorise the children into risk categories of poor intake of Vitamin A-containing foods. About 20% of children in Zaria (controls) were at moderate-to-high risk of poor intake, while 37.3% were at low risk and 42.7% had satisfactory intake of Vitamin A-rich foods. Among the malnourished patients, 53.4% were at moderate-to-high risk of poor intake, while 21.3% were at low risk and 25.3% had satisfactory intake of Vitamin A-rich foods. In the study population, there was high consumption of palm oil and dark leafy vegetables hence the high mean UPF score and a relatively lower moderate-to-high risk of poor intake for the controls as compared to lower consumption of palm oil and green leafy vegetable and hence higher moderate-to-high risk of poor intake in the malnourished children. An important limitation which may be considered in dietary intake data is that the researcher relied entirely on information collected through dietary recall during a single visit of the children in the study period. This is because long periods of direct dietary intake observation are difficult to obtain. Beside, responses to dietary questionnaires are not always accurate.[12] It is also possible that there may be overestimation of the child's intake by the mother as documented by Hankin et al.[12] with the use of dietary questionnaire. Although the children may be taking such high Vitamin A-rich foods, the bioavailability of retinol to the body might be low because of the general practice of bleaching palm oil as confirmed from the mothers during data collection. Furthermore, prolonged cooking of vegetables as generally practiced by the mothers may result in decreased Vitamin A activity. There is also variability in the conversion of lycopene present in palm oil and β-carotene present in vegetables to retinol in the body.[13] The finding in this study was similar to the study done in under-five children in Ijaiye Orile[13] In Cameroon where VAD is a public health problem, 54% of the children aged <72 months were of moderate-to-high risk.[14]

 Conclusion



This study was able to establish low intake of Vitamin A-rich foods in undernourished children as compared to well-nourished children in Zaria. There were statistically significant differences in the mean serum Vitamin A levels for different UPF scores between cases and controls (P = 0.0001, t = 9.139).

Recommendations

It is therefore recommended that a follow-up study should be conducted in the area to re-analyse the dietary consumption of Vitamin A-rich foods in children and compare the result with the rural children or children from another ethnic group in Nigeria to have a better estimate of normal dietary intake of Vitamin A-rich foods among Nigerian children. Children who are 6–59 months of age with severe acute malnutrition should receive the daily recommended nutrient intake of Vitamin A throughout the treatment period. Children with severe acute malnutrition should be provided with about 5000 IU Vitamin A daily, either as an integral part of therapeutic food or as part of a multi-micronutrient formulation.

Limitations

An important limitation which may be considered in dietary intake data is that the researcher relied entirely on information collected through dietary recall during a single visit of the children in the study period. This is because long periods of direct dietary intake observation are difficult to obtain. This could have provided valuable information on nutritional status.

Acknowledgements

We acknowledge with thanks, the staff of paediatrics and chemical pathology departments and ICH ABUTH Zaria.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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