Vitamin D Deficiency and Its Predictors in a Country with Thirteen Months of Sunshine: The Case of School Children in Central Ethiopia

Abstract

Studies examining vitamin D status among children living in sunny climates indicated that children did not receive adequate vitamin D, however, this has not been looked at among children living in Ethiopia. In this study, we determined vitamin D deficiency and its predictors among school children aged 11–18 years, examining circulating 25-hydroxy vitamin D [25(OH)D]. The school-based cross-sectional study was conducted in schools in Adama Town (n = 89) and in rural Adama (n = 85) for a total sample of 174. Students were randomly selected using multi-stage stratified sampling method from both settings. Socioeconomic status of parents and demographic, anthropometric, sun exposure status and blood 25(OH)D levels were obtained. Vitamin D deficiency, defined as circulating levels of 25(OH)D <50 nmol/L, was found in 42% of the entire study participants. Prevalence of deficiency was significantly higher among students in urban setting compared to rural (61.8% vs 21.2%, respectively, p<0.001). After controlling for potential confounders using multivariable logistic regression model, duration of exposure to sunlight, amount of body part exposed to sunlight, place of residence, maternal education, body fatness, having TV/computer at home and socioeconomic status were significant predictors of vitamin D deficiency. The findings suggest that Vitamin D deficiency was prevalent in healthy school children living both in urban and rural areas of a country with abundant year round sunshine providing UVB, with the prevalence of deficiency being significantly higher among urban school children who were less exposed to sunlight. Behaviour change communication to enhance exposure to ultraviolet light is critical to prevent vitamin D deficiency in tropical country like Ethiopia. Further study is required to assess the deleterious effect of its deficiency on bone mineral homeostasis of growing children in Ethiopia during their most critical period of bone development.

Comparisons of physical activity, adipokines, vitamin D status and dietary vitamin D intake among adolescents

“…Wakayo et al . , when evaluating Ethiopian adolescents with this questionnaire, did not report the results obtained using the scores, although the duration of exposure to sunlight and the extent of body parts exposed to sunlight was found to predict vitamin D deficiency. The present study, however, did not find any association with this questionnaire, nor did that of Forney et al .…”

“…Positive (but moderate) correlations of sun exposure score and 25(OH)D concentrations were also seen among North-American youths (1-21 years old) (41) . Wakayo et al (42) , when evaluating Ethiopian adolescents with this questionnaire, did not report the results obtained using the scores, although the duration of exposure to sunlight and the extent of body parts exposed to sunlight was found to predict vitamin D deficiency. The present study, however, did not find any association with this questionnaire, nor did that of Forney et al (43) investigating North-American college-aged youths or that of Sham et al (44) investigating young Canadian adults (18-35 years old).…”

Prevalence of Vitamin D Deficiency in a Population of Indian Women- A Call for Universal Supplementation?

“…With improvement in serum vitamin D testing, there emerged an understanding that VDD exists in sunny regions of the world where it was once thought to be a rare occurrence. [10][11][12] Indeed, reports of widespread VDD in south Asian populations began to appear in the early 2000s. [13][14][15][16][17] Included in this evidence were reports, now more than 10 years old of widespread VDD in pregnant and postmenopausal women in India.…”

“…In addition to risks associated with dietary deficits of vitamin D rich foods, individuals with limitations to sun exposure have been identified as having an increased risk for VDD. 12,32 Limitations to sun exposure in sunny regions have been linked to cultural clothing norms of extensive body covering and changes in lifestyle due to urbanisation resulting in fewer hours out-of-doors. 12,32 The last few years have revealed that certain genetic variants in the Vitamin D Receptor (VDR) gene can influence vitamin D levels and disease in these populations as well.…”

“…12,32 Limitations to sun exposure in sunny regions have been linked to cultural clothing norms of extensive body covering and changes in lifestyle due to urbanisation resulting in fewer hours out-of-doors. 12,32 The last few years have revealed that certain genetic variants in the Vitamin D Receptor (VDR) gene can influence vitamin D levels and disease in these populations as well. [33][34][35][36] The aim of this study was to explore the prevalence of VDD among pregnant and non-pregnant women at a Multispecialty Hospital in Bengaluru, India.…”