|Year : 2020 | Volume
| Issue : 3 | Page : 339-344
Vitamin D status in Egyptian young children and its correlation with iron deficiency
Esaad M Menazie1, Heba T Okda1, Noha M El Tabiey2, Noha M Kamel3
1 Department of Pediatrics, Faculty of Medicine for Girls, Al-Azhar University, Cairo, Egypt
2 Department of Pediatrics, General Port Fouad Hospital, Port Said, Egypt
3 Department of Clinical and Chemical Pathology, Faculty of Medicine, Suez Canal University, Ismailia, Egypt
|Date of Submission||16-Feb-2020|
|Date of Decision||29-Feb-2020|
|Date of Acceptance||01-Mar-2020|
|Date of Web Publication||2-Oct-2020|
Noha M Kamel
Department of Clinical and Chemical Pathology, Assistant Professor of Clinical Pathology, 4.5 K, Ring Road, Department of Clinical and Chemical Pathology, Faculty of Medicine, Suez Canal University, Ismailia
Source of Support: None, Conflict of Interest: None
Background Vitamin D deficiency (VDD) and iron deficiency are two common nutritional problems and cause a variety of health issues in children even if they are asymptomatic. The potential relationship between the two remains poorly understood.
Propose To study the status of vitamin D in Egyptian young children and its correlation with iron deficiency.
Patients and methods This cross-sectional study included 85 apparently healthy Egyptian children between 6 and 9 years old randomly selected from pediatric outpatient clinic of General Port Fouad Hospital, Port Said City, in the period from July to November 2019. A written informed consent was taken from all participants’ parents after proper explanation of the study. All children were subjected to complete history taking, anthropometric measurements, systemic examination, and laboratory investigations, including complete blood count, serum vitamin D level, serum iron, and ferritin level, which were performed for children expected to have iron deficiency through red blood cells indices in complete blood count.
Results A total of 85 patients (age, 7.36±1.1 years; male to female ratio was 1 : 1) were classified according to their 25-hydroxyvitamin D levels into three groups: VDD 40% (<20 ng/ml), vitamin D insufficiency 40% (20–29 ng/ml), and vitamin D sufficiency 20% (≥30 ng/ml). Of 24 suspected iron-deficient cases, 80% of them were in the VDD+insufficient vitamin D groups compared with 20% in the sufficient group (P<0.001).
Conclusion Among the apparently healthy young Egyptian children, VDD is common with increased risk of iron deficiency. There is a significant positive correlation between vitamin D level and age, hemoglobin, mean corpuscular volume, mean corpuscular hemoglobin, and serum iron levels but not with serum ferritin level. Physicians should therefore ensure that vitamin D levels are evaluated in anemic children and provide adequate supplementation to prevent deficiencies of both nutrients.
Keywords: anemia, ferritin, iron, vitamin D
|How to cite this article:|
Menazie EM, Okda HT, El Tabiey NM, Kamel NM. Vitamin D status in Egyptian young children and its correlation with iron deficiency. Sci J Al-Azhar Med Fac Girls 2020;4:339-44
|How to cite this URL:|
Menazie EM, Okda HT, El Tabiey NM, Kamel NM. Vitamin D status in Egyptian young children and its correlation with iron deficiency. Sci J Al-Azhar Med Fac Girls [serial online] 2020 [cited 2020 Oct 20];4:339-44. Available from: http://www.sjamf.eg.net/text.asp?2020/4/3/339/296927
| Introduction|| |
Vitamin D from diet or dermal synthesis is biologically inactive and requires enzymatic conversion to active metabolites. Vitamin D is converted to 25-hydroxyvitamin D [25(OH) D], the major circulating form of vitamin D, and then to 1,25-dihydroxyvitamin D, the active form of vitamin D, by enzymes in the liver and kidney. 1,25-hydroxyvitamin D binds to the intracellular vitamin D receptor to activate vitamin D response elements within target genes. The half-life of 1,25-dihydroxyvitamin D is 4–6 h, compared with 2–3 weeks for 25(OH) D and 24 h for parent vitamin .
Iron-deficiency anemia (IDA) is a global public health problem, affecting 1.62 billion people , IDA is found to be the most common cause of anemia among Egyptian children of low socioeconomic standard, affecting 43% of them .
Iron plays an important role in children’s growth and development, such as brain development, cognitive function, motor function, behavior, and immunity .
Iron deficiency and vitamin D deficiency (VDD) are the two most common deficiencies in young children worldwide .
Health programs aimed to achieve adequate iron and vitamin D intake at an early age should be conducted to prevent deficiencies .
Data reported by studies show the role of vitamin D in iron metabolism and erythropoiesis . This study aimed to assess the status of vitamin D in Egyptian young children and its correlation with iron deficiency.
| Aim|| |
The aim was to study the status of vitamin D in Egyptian young children and its correlation with iron deficiency.
| Patients and methods|| |
The protocol was approved by the local research ethics committee of Al-Azhar University for Girls, and a written informed consent was taken from all participants’ parents after proper explanation of the study.
This was a cross-sectional study performed in the pediatric outpatient clinic of General Port Fouad Hospital, Port Said City, between July and November 2019. This study included 85 Egyptian children with age ranged from 6 to 9 years (i.e. without any known chronic or recent acute diseases); both sexes were included.
The following were the exclusion criteria:
- Known infection during the last week or infection needing medical assistance or treatment during the last 2 weeks.
- Known hemoglobinopathies and parathyroid diseases.
- Known rheumatic or collagen disorders.
- Receiving iron or vitamin D supplementation.
- Any case of anemia treated in the last 3 months.
- Blood transfusion received within the last 6 months.
- The presence of a relevant congenital abnormality, chromosomal disorder, or severe disease.
During the period of the study, all included children were subjected to history taking, anthropometric measurements and centile, systemic examination, and laboratory investigations, including complete blood count, serum vitamin D level, serum iron, and serum ferritin level, which were performed for children expected to have iron deficiency through red blood cell (RBC) indices in complete blood count demonstrating a microcytic hypochromic anemia with a high red cell distribution width (RDW), reduced RBC, normal white blood cell, and normal or elevated platelets count.
Specimen collection and handling
Overall, 4 ml of whole blood was collected by venipuncture; 2 ml in EDTA vacutainers and 2 ml in plain vacutainers. It was allowed to clot and was separated to obtain serum by centrifugation at room temperature. Specimens were held for 2 months, frozen at −20°C. A commercially available kit (Orgentec Diagnostika GmbH, Mainz, Germany) was used for assessment of 25-OH vitamin D (total) by enzyme-linked immunosorbent assay. Complete blood count including RBC indices was measured using cell counter (ABX Micros 60, Mundolsheim, France). Serum iron level was measured using Cobas 6000 analyzer. Serum ferritin level was performed on Cobas e411 autoanalyzer, Roche Diagnostic, Indianapolis, USA.
Data were collected, coded, and entered to the Statistical Package for Social Science (IBM SPSS), version 23.0. The quantitative data were presented as mean, SDs, and ranges when parametric, and median and interquartile range when data were nonparametric. Moreover, qualitative variables were presented as number and percentages. The comparison between groups regarding qualitative data was done by using c2 test and/or Fisher exact test. The comparison between more than two groups regarding quantitative data and parametric distribution was done by using one-way analysis of variance test, whereas with nonparametric distribution was done by using Kruskal–Wallis test. Spearman correlation coefficients were used to assess the correlation between two quantitative parameters in the same group. The confidence interval was set to 95%, and the margin of error accepted was set to 5%. P value less than 0.05 was considered significant (S), and P value less than 0.01 was highly significant (HS).
| Results|| |
Demographic and anthropometrics measurement are shown in [Table 1]. Children were divided into three groups according to vitamin D status. Of 85 children, 34 (40%) had insufficient vitamin D (VDI) levels (21–30 ng/ml), 34 (40%) had VDD (<20 ng/ml), whereas 17 (20%) had sufficient levels of vitamin D (≥30 ng/ml).
|Table 1 Demographic data and anthropometric measurements of the studied children|
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There was a statistically significant positive relation found between vitamin D and age of the studied children but not with their sex, weight, and height measures ([Table 2]).
|Table 2 Comparison of vitamin D status according to demographic and anthropometric measurements among the studied children (N=85)|
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There was a statistically significant decrease in the level of hemoglobin, mean corpuscular volume (MCV), and mean corpuscular hemoglobin (MCH) in deficient and VDI cases than sufficient cases, whereas there was a statistically significant increase in RDW levels in deficient and insufficient cases than sufficient cases ([Table 3]).
|Table 3 Comparison of vitamin D status according to complete blood count results among the studied children|
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The median (interquartile range) of vitamin D, serum iron, and serum ferritin level is shown in [Table 4].
|Table 4 Descriptive table of vitamin D level, serum iron, and ferritin level|
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Number of children with suspected iron deficiency was 24 (28.2%); eight (36%) of them were VDD, 11 (44%) were vitamin insufficient, and only five (20%) were sufficient vitamin D level. Patients with VDD also had significantly lower levels of iron in comparison with insufficient and sufficient group with P value of 0.011 ([Table 5]).
|Table 5 Comparison of vitamin D status in relation to serum iron results among the suspected iron-deficiency cases (N=24)|
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There was a statistically significant positive correlation between vitamin D level and serum iron level ([Figure 1]).
|Figure 1 Median serum iron level in deficient, insufficient, and sufficient vitamin D groups.|
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Using Kruskal–Wallis test, there was a decrease in the level of serum ferritin in deficient group than sufficient and insufficient groups, but it did not reach statistical significance (P=0.646).
| Discussion|| |
Vitamin D and iron are important nutrients required for the growth and development of children. The goal of the present study was to assess 25 (OH) vitamin D status in the apparent healthy young Egyptian children and its correlation with iron deficiency in those children. For this purpose, 85 children recruited from pediatric outpatient clinic of General Port Fouad Hospital, Port Said, were included in the study.
Children (age, 7.36±1.1 years; male to female ratio was 1 : 1) were divided into three groups according to vitamin D status. Of 85 children, 34 (40%) had VDI levels (20–29 ng/ml), 34 (40%) had VDD (<20 ng/ml), whereas 17 (20%) had sufficient levels of vitamin D (≥30 ng/ml). These findings of low vitamin D level is possibly owing to the lack of fortification of food with vitamin D. Only a few natural foods contain significant quantities of vitamin D, and supplementation is essential to achieve the recommended levels. Therefore, vitamin D was decreased despite adequate caloric intake. This explanation was supported by the results of Liu . Moreover, the modern lifestyle with little to no sun exposure could be some of the reasons for deficient/VDI levels. In addition, it could be owing to genetic polymorphisms .
In this study, 24 (28.2%) of the children had iron deficiency through their complete blood count, demonstrating a microcytic hypochromic anemia with a high RDW, reduced RBC, normal white blood cell, and normal or elevated platelets count that was sufficient for presumptive diagnosis .
Of 24 suspected iron-deficient cases, 80% were in the vitamin D-deficient groups (VDD+VDI), whereas only 20% in the vitamin D-sufficient group. Patients with VDD also had significantly lower levels of iron in comparison with VDI and vitamin D-sufficient groups.
There was a decrease in the level of serum ferritin in deficient group than sufficient and insufficient groups, but it did not reach statistical significance owing to lower number of cases.
In a study that included children aged 3 months to 12 years from northern India, 66% of the children with anemia and 35% of healthy children were found to have VDD . In another study that was held in Korea, 58% of the children aged 4 months to 11 years with IDA had low vitamin D levels. They showed ∼39% of their study population had VDD. However, children with VDD and VDI did not have comparatively lower serum levels of hemoglobin, ferritin, and iron than those with normal serum vitamin D levels. They could not detect an association between IDA and the severity of VDD .
However, VDD may predispose patients to anemia, as several observations suggested the role of vitamin D in erythropoiesis and the correlation of VDD and a greater risk of anemia .
In the present study, there was a statistically significant positive correlation found between vitamin D level and hemoglobin, MCV, MCH, and serum iron levels, whereas there was no statistically significant correlation between vitamin D level and serum ferritin level. Moreover, there was a statistically significant negative correlation between vitamin D level and RDW levels.
In another study conducted in Al-Medina, 37.9% of all rachitic children were anemic. Furthermore, the hemoglobin level was lower in children with active rickets in comparison with healed rickets . According to them, vitamin D plays a role in proliferation and differentiation of stem cells in bone marrow and may play a role in red cell proliferation. A deficiency of vitamin D may therefore affect the hemoglobin metabolism and give rise to anemia .In our study, the median serum level of vitamin D was 22.39 ng/ml, serum iron was 32 µg/dl, and serum ferritin was 22 ng/ml.
In agreement with us, Gülez et al. , reported that VDD was present in 31% of infants. The mean concentration of serum 25(OH) D was 28.1±14.7 ng/ml (range, 3.0–70 ng/ml).
Moreover, Stagi et al.  evaluated 25(OH) D levels in 679 Italian children and adolescents. Overall, 58.7% had 25 (OH) D deficiencies. Mean 25(OH) D level was 19.08±8.44 ng/ml.
We found a positive correlation between younger age and VDD in spite of the asymmetrical distribution of age in our patients. Another study suggested that age younger than 5 years was a risk factor for VDD .
These are several limitations that need to be taken. First, the sample size was small, as it may not be sufficiently representative to detect deficiency or to allow values lower than the average to be discriminated. Second, there was the various methods of assessment for VDD and anemia used among studies. However, the results did not significantly change. Furthermore, the lack of a nutritional survey of the sample being studied should be taken into account, along with time exposed to the sun, as there is the possibility that the true situation is not adequately reflected.
| Conclusion|| |
- There was a high prevalence of VDD and iron deficiency in apparently healthy young children with age ranged from 6 to 9 years old in Port Said governorate, the significance of which must warrant public health intervention.
- We found a positive correlation between younger age and VDD.
- There was a statistically significant positive correlation found between vitamin D level and hemoglobin, MCV, MCH, and serum iron levels.
- There was no significant correlation between sex, anthropometric measures, and serum ferritin with serum vitamin D level.
We recommend the following:
- Adequate vitamin D and iron intake should be initiated at an early age to prevent deficiency.
- It is important to early detect VDD and iron deficiency in young children.
- Vitamin D levels should be evaluated in anemic children, and they should be provided adequate supplementation to prevent deficiencies of both nutrients.
- Further large-scale studies are necessary to define the national prevalence of vitamin D and iron deficiencies in Egyptian young children and to confirm the association between the two nutrient deficiencies.
- The erythrocyte sedimentation rate and C-reactive protein are recommended to be evaluated for iron-deficient children with normal serum ferritin level to rule out infection.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2], [Table 3], [Table 4], [Table 5]