RESEARCH PAPER 1 Essay Example

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Risk Factors for Vitamin D Deficiency and Iron Deficiency among East African Immigrants in Temperate Climates

Risk Factors for Vitamin D Deficiency and Iron Deficiency among East African Immigrants in Temperate Climates


In the recent years, an increased number of people from the Sub-Sahara especially East African have migrated to industrialized countries with high income such the USA, Western Europe, Canada and Australia. Reports on research conducted by Australia and overseas show high rates of iron and vitamin D deficiency (VDD) among the East African Immigrant adults. These increased rates of Vitamin D deficiency among the East African immigrant adults in temperate climates suggests that immigrant children are also at risk of the same. VDD negatively affects children, adolescents, adults and even infants. VDD restricts the growth of infants during pregnancy, causes rickets in children, andosteomalacia in adolescents and adults (McGillivray et al., 2007). Iron deficiency can lead to arrhythmiasis, heart enlargement, heart murmur and heart attack.

Researchers have evaluated the prevalence, severity, pattern and VDD risk factors amongst Sub Saharan immigrant children. From previous research, the risk factors for VDD include younger ages, longer times of residence in host country, female gender; wearing covering clothes, 25 OHD tested in spring and winter, and decreased daylight exposure (McGillivray et al., 2007, &Renzaho et al., 2011). However, the general pattern associated with these risk factors for VDD shows reduction in UVR exposure. Unlike VDD, the risk factors for Iron deficiency are few. The most significant risk factor for iron deficiency is the time length for breastfeeding. This paper will explain how specific risk factors affect iron and vitamin D deficiency among East African Immigrants in temperate climates.

Literature Review

Continuous increase in number of immigrants to more industrialized and temperate countries has posed great health concerns in the host countries. Researchers and medical offices have been conducting researches on the health conditions of the immigrants especially on nutritional deficiency diseases like Vitamin D deficiency, Iron deficiency, and their relationship with high rates of infectious diseases like Tuberculosis, prostate cancer, type 2 diabetes (T2D), breast cancer, colon cancer and cardiovascular diseases. Most of the reports from these researches indicate high prevalence of iron deficiency and vitamin D deficiency (VDD) and among the East African Immigrants. Due to the negative effects of these deficiencies, it is necessary to research on the risk factors for both deficiencies in order to control them.

Researchers in Australia determined the prevalence, severity, VDD risk factors and their pattern amongst immigrant children. Research documented by McGillivray et al (2007), found high prevalence of iron deficiency and vitamin D deficiency (VDD) among the young East African immigrants living in temperate climates. The objective of the research was to study the pattern of the VDD risk factors in immigrant East African children in Melbourne, Australia. Research’s methodology included the use of questionnaires, medical assessment and laboratory tests for 232 immigrant children from East Africa. The results for the research indicated that 87% of them had low 25-hydroxyvitamin D (25-0HD< 50 nmol/l) and 44% Vitamin D deficiency (25-OHD<25 nmol/l). VDD risk factors included female gender, less than 5 years of age, increased time in Australia, winter/spring season and decreased daylight exposure. A 19% case of iron deficiency was also noted. The research recommends for the Vitamin D deficiency assessment for all immigrant children (dark skinned), adolescents and those wearing covering clothes on their arrival in more temperate regions.

This research by McGillivray et al is evident of the health condition concerns in Australia and other temperate regions. The research identifies the prevalence, pattern, severity and risk factors for iron and vitamin D deficiency. It lowly accounts for the risk factors and doesn’t research on the effect of specific risk factors for vitamin D and iron deficiency.

Another research documented by Renzaho et al (2011) is the first one in Australia that measured the metabolic syndrome and cardiovascular disease risks simultaneously among the most recent East African immigrants and refugees. The research aimed to assess the Vitamin D insufficiency prevalence, and type 2 diabetes and cardiovascular disease risk factors among African refugee and immigrant adults in Melbourne. The research methodology included the use of questionnaires, medical assessment and laboratory tests for 50 men and women participants. The research results indicated 82.8% prevalence of vitamin D insufficiency among males and 95.6% among females. It was also found that VDI prevalence is not dependent on age, length of stay in Australia and gender. Prevalence of overweight was found to be 85.7% of women and 44.8% of men. The research recommends increased screening and intervention efforts by hosting governments.

This research indicates high prevalence levels of VDI (25-OHD<50 nmol/l) among East African Immigrants and refugees in Australia. The research also recognizes Vitamin D deficiency risk factors. Although the researchers indicate that the prevalence for Vitamin D insufficiency does not vary by these factors, it is evident from data that it does vary. If we consider the results of the research, it is indicated that the percentage of men and female with VDI prevalence is 82.8% and 95.6% respectively. This means that more women have the prevalence for VDI than men, hence the prevalence varies by gender. The research should have also included immigrant children because there is high possibility that they have high prevalence too for VDI.

Research has also been conducted in Melbourne among the African immigrant patients who attended infectious diseases clinics between January 1, 2003 and June 30, 2006 (Gibney et al, 2009). The research comprised of an audit of patients attending clinics for infectious disease at the Royal Melbourne Hospital. The hospital registration database identified all patients according to their country of birth. This research’s data was obtained from the hospital pathology, patients’ medical records, and radiology records. The researchers also obtained data on the patients’ sex, age, date of arrival in Australia among others. They also collected data regarding vitamin D deficiency, infectious diseases, and hematologic indices.

The results of the research indicates that over 70% of the patients from Sub-Saharan Africa had prevalence for vitamin D deficiency. The research also found that the rate of severe vitamin D in this study was at 42.4%. This result is slightly higher than 29% found in the research among African immigrants who attend health assessments in Melbourne. This research recommended that there is need for the health system to be aware of increased rates of health problems that are often undiagnosed among the African refugees and immigrants. It does emphasize the significance of policies that will support a comprehensive screening for nutritional deficiencies and infectious diseases.

This research takes into consideration vitamin D deficiency risk factors such as age, sex, and time of stay in Australia but does not analyze their effect on the results outlined. The research also noted that vitamin D deficiency has a close relationship with the high rates of Tuberculosis (TB), breast, prostate and colon cancer, but does not explain the relationship clearly. The research does not include iron deficiency among the nutrition deficiency diseases despite its high prevalence among these African immigrants.

Based on all these previous health researches, vitamin D deficiency among the Sub-Saharan immigrants living in temperate regions is the common research topic. There is less research work on iron deficiency among these African immigrants. Researches documented by McGillivray et al (2007) and Renzaho et al (2011) note the common risk factors for iron deficiency and vitamin D deficiency among the East African immigrants. These factors include age, gender, time length spent by the immigrants in temperate regions, winter/spring season and decreased daylight exposure. However, Renzaho et al (2011) contradict the research results by commenting that the prevalence for VDD does not vary by these risk factors. It is worthy to note that none of these researches explained the significance of each risk factor for VDD and iron deficiency. Therefore, this paper will research on the effect of specific risk factors on iron deficiency and vitamin D deficiency.


This research paper employs retrospective audit of patient data attending outpatient clinics in Melbourne, Australia. The data was mostly collected by trained interpreters using design questionnaires. Data is also obtained from the previous research reports on the same topic and in Melbourne by other researchers who used the same method of questionnaires to collect it. Data collected is majorly on the country of origin, sun exposure, sex, age and time spent in Australia by immigrants from Sub-Saharan Africa. In some cases, the participants were assessed by pediatrician to ascertain illness, vitamin D and iron deficiency. The following data were collected for this paper.

Table 1. Demographic, nutritional, univariate risk factor and data for 232 East African (McGillivray, 2007)

Demographic data

All children

25-OHD <25nm/l

n=103 (44%)

25-OHD ≥25nm/l

n=129 (56%)

Risk ratio

Mean (SD), age(years)

8.9 (4.4)

9.9 (4.5)

8.2 (4.2)

Diff 1.7 (0.6 to 2.8)

107 (46%)

1.5 (1.1 to 2.0)

Univariate risk factors for VDD

Median (IQR)months in Australia

7.9 (3.2-35)

10.7 (5-37)

5.0 (2.3-25)


Resident in Australia >6 months

126 (54%)

2.0 (1.5 to 2.9)

Exposed ≤14 h daylight/week

1.8 (1.3 to 2.4)

With head cover

2.4 (1.9 to 3.1)

Tested winter/spring

103 (44%)

2.2 (1.6 to 3.0)

Nutritional data

Underweight for age

1.1 ( 0.4 to 29)

Stunting (height for age)

1.8 (0.6 to 5.4)

Overweight (BMI)

1.0 (0.3 to 3.3)

Vitamin A deficiency

1.7 (1.2 to 2.2)

1.1 (0.8 to 1.5)

Iron deficiency

0.8 (0.5 to 1.2)

Iron deficiency anemia

0.9 (0.5 to 1.5)

Table 2. Definitions of deficiency as used in this study (McGillivray, 2007)

Clinical Entity

Laboratory Test

Vitamin D deficiency

Serum 25-OHD

<25 nmol/l

Vitamin D insufficiency

Serum 25-OHD

≥25 nmol/l and <50 nmol/l


Aged < 2 years aged 2-5 years aged 6-11 years aged ≥12

<105 g/l <110g/l <115g/l <120 g/l

Iron deficiency

Serum ferritin

Aged <6years aged 6-9 years aged ≥10years

<0.6mg/l <1.0mg/l males <2.3mgl/

Females <0.6mg/l

Table 3. Multivariate analysis of Risk factors for vitamin D deficiency (McGillivray, 2007).


Odds ratio (95% cl)

Age <5years

1.5 (1.0 to 2.2)

2.1 (1.1 to 4.1)

Time >6 months in Australia

3.4 (1.8 to 6.7)

Sun exposure ≤14 h /week

3.3 (1.3 to 8.5)

Vitamin D tested winter/spring

9.0 (3.7 to 22.0)

Table 4. Vitamin D insufficiency by gender (Renzaho et al, 2011)



Prevalence for 25-OHD (vitamin D) levels

< 50nmol/l

≥50-<75.0 nmol/l


25-OHD nmol/l: mean (SD)

22.9 (12.9)

30.4 (20.2)


Table 5. Characteristics of 258 most recent African refugees seen in general practice clinics in Melbourne, 2005 (Toing, 2006)


0-14 years

128 (50%)

15-62 years

130 (50%)

144 (56%)

114 (44%)

Country of birth

Eastern Africa

170 (66%)

Western Africa

Central Africa

Data Analysis and Results

In this paper, relative risks have been calculated as risk ratios. Cloth covering the head is a marker for sun exposure limiting. Multivariate logistic regression model was also performed in assessing Vitamin D deficiency risk factors. The dependent variable for this model is VDD while the independent variables include: gender, age, time in Australia, iron efficiency, duration of breast feeding, season of 25-OHD test, vitamin A deficiency, and sun exposure.

From table 1, a total of 96 children were found to have spent 2.7 years, a median of 1.5-4.3 interquartile range in refugee camps before their migration to Australia. They have stayed in Melbourne for 8 months, a median of 3-35, 0.4-88 interquartile range. From the findings, vitamin D deficiency affected 44% children (103 children) while vitamin D insufficiency affected 202 children (87%). Table 4 shows that the prevalence for VDI among men is 82.8% and 95.0 % in women.

Results of univariate analysis shows that those children with VDD are possibly older, female, have decreased daylight exposure, have stayed in Australia for longer, they wear head covering clothing, tested 25-OHD in spring or winter. Results of multivariate also shows that VDD is closely associated with age below 5 years, more than 6 months of stay in Australia, female gender, tested in winter and spring, and 25- OHD decreased daylight exposure (≤ 14 h/week). Ultra violet radiation measurements were also found to influence vitamin D levels. It resulted that, vitamin D levels were lagging behind ultra violet radiation levels as it followed a parallel curve to that of Ultra violet Radiation with the occurrence of nadir during winter.

Similarly, it was found that spent in refugee camps did not have a significant effect on the risk for anemia, iron deficiency and iron deficiency anemia. High prevalence for anemia was found in children aged below 5 years. During the period of research, 96% (220) of the children were being or had been breastfed for a median duration of 12 moths. Those children who were breastfed more than 12 moths were more prevalent for iron deficiency as compared to those children breastfed for shorter periods.


This study has documented the effects of specific vitamin D deficiency and iron deficiency risk factors. Sub-Saharan immigrants to temperate climate regions have high prevalence for iron deficiency and Vitamin D deficiency. The risk factors for iron deficiency and VDD differ in the severity of their influence. The pattern for vitamin D deficiency risk factors have been found to be younger age (<5 years), female gender, longer time of residence in Australia, decreased or no daylight exposure and testing 25-O HD in winter.

Children have been found to be more prevalent for VDD than older people. Females have also been found more prevalent than males to VDD. Wearing covering clothing marks a decreased daylight exposure and increased VDD prevalence significantly. Lastly, long time spent in Australia increases the prevalence for vitamin D deficiency among these Sub-Saharan Africa community. In general, VDD has been found to result from inadequate endogenous vitamin D production among the East African children. On the other hand, the most significant risk factor for iron deficiency is the time length for breastfeeding (more than 12 months).


In summary, Sub- Saharan Africa immigrants to temperate climate regions have high prevalence than immigrants from other nations. Those from East Africa have the highest prevalence, followed by those from western Africa countries and lastly those from central Africa. This paper carried a study from the previous research papers conducted on the same health topic and found that VDD has more than one risk factors. These risk factors have also been found to differ in the severity of their influence. The pattern of vitamin D deficiency risk factors have been found to be younger age (<5 years), female gender, longer period of residence in Australia, no or decreased daylight exposure and testing 25-OHD in winter. On the other hand, the risk factors pattern for iron deficiency are time length for breastfeeding (more than 12 months).

There is need to understand in detail the risk factors for VDD to determine ways of reducing its prevalence among the East African immigrants. This necessitates Vitamin D deficiency assessment for all immigrant children (dark skinned), adolescents and those wearing covering clothes on their arrival in more temperate regions. Hosting governments should have interventions to control cases of VDD and iron deficiency among the immigrants.

It is important to observe the ethical codes while conducting research of these kinds by obtaining informed consents of participants and involving the government or any other health organization in charge. Also the health organizations and hosting countries should be able to provide relevant and up to date data for more research that may be necessary regarding to the same topic. I therefore recommend that more data that is up to date be provided and more study be conducted on especially the risk factors for iron deficiency.


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