|Year : 2013 | Volume
| Issue : 2 | Page : 75-82
Vitamin D deficiency and risk of dental caries among young children: A public health problem
Abdulbari Bener1, Mohammed S Al Darwish2, Georg F Hoffmann3
1 Department of Medical Statistics and Epidemiology, Hamad General Hospital, Hamad Medical Corporation, Weill Cornell Medical College, Doha, Qatar
2 Department of Dentistry, Rumailah Hospital, Hamad Medical Corporation, Doha, Qatar
3 Department of Pediatrics, Center for Pediatrics and Adolescent Medicine, University of Heidelberg, Heidelberg, Germany
|Date of Submission||01-May-2013|
|Date of Acceptance||19-Sep-2013|
|Date of Web Publication||15-Oct-2013|
Department of Medical Statistics and Epidemiology, Hamad General Hospital, Hamad Medical Corporation and Department of Public Health, Weill Cornell Medical College, PO Box 3050, Doha
Source of Support: This research was supported by the by the Qatar National Research Fund- QNRF NPRP 08-760-3-153. The sponsor of the study had no role in study design; in the collection, analysis and interpretation of data; in the writing of this report; and in the decision to submit the paper for publication, Conflict of Interest: None
Aim: The aim of the present study was to determine the prevalence of dental caries and the impact of vitamin D deficiency and other possible associated socio-demographic and life-style habit risk-factors for dental caries.
Subjects and Methods: A cross-sectional study was conducted among children 7-16 years of age who visited Primary Health-Care Centers (PHCs). A random sample of 1,752 children aged below 16 years who visited the PHCs was approached and parents of 1,249 children expressed their consent with a response rate of 71%. The study was based on socio-demographic information, life-style and clinical information as well as laboratory investigations for biochemical assessment of vitamin D status. Furthermore, the study provides mean and standard deviation (SD), number of decayed teeth (DT), missing teeth (MT), filled teeth (FT) and decayed missing and filled teeth (DMFT) across different socio-demographic and anthropometric characteristics of the participants. The status of dental caries was recorded according to the World Health Organization criteria.
Results: The prevalence of dental caries with 95% of the confidence interval among children with vitamin D deficiency was very high 59% (56.7-61.3) compared with the control population (52% [48.2-55.8]). The mean number of FT were significantly higher among the age group of 10-13 years as compared with 7-10 years (mean 1.05 [0.08] vs. mean 0.75 [0.07]; P < 0.05 respectively]. mean (SD) number of DT (2.23 [0.10] vs. 2.64 [0.10]), MT (0.07 [0.02] vs. 0.65 [0.04]), FT (0.19 [0.03] vs. 1.64 [0.07]) and DMFT (2.49 [0.11] vs. 4.92 [0.15]) were significantly lower among children with optimal levels of serum vitamin D when compared with those with deficient serum vitamin D. In addition, children with a family history of vitamin D deficiency were having significantly higher mean (SD) number of DT (2.69 [0.12] vs. 2.28 [0.09]; P < 0.01], MT (0.45 [0.04] vs. 0.29 [0.03]; P < 0.01), FT (1.14 [0.08] vs. 0.73 [0.05]; P < 0.01) and DMFT (4.29 [0.18] vs. 3.31 [0.12]; P < 0.01) as compare to children without a family history of vitamin D deficiency. The predictors of dental caries an experience based on multivariable Poisson regression analysis revealed that children with deficient levels of serum vitamin D were 1.13 times more at risk of dental caries compared to those with optimum serum vitamin D (adjusted relative risk [RR]: 1.13; 95% of confidence interval [CI]: 1.05-1.21; P < 0.01) after adjusting for all potential confounders in the model. In addition, deficient levels of serum calcium were also independently associated with a number of dental caries (adjusted RR: 1.21; 95% CI: 1.11-1.31; P < 0.01). The risk of dental caries was also significantly higher among children of non-consanguineous parents as compared to those with consanguineous parents (P = 0.025).
Conclusion: The prevalence of vitamin D deficiency is high in dental caries children and more common in girls. Vitamin D deficiency appears as a result from a combination of limitations in sunlight exposure and a low oral intake of vitamin D.
Keywords: Dental caries, lifestyle, risk factors, vitamin D deficiency
|How to cite this article:|
Bener A, Al Darwish MS, Hoffmann GF. Vitamin D deficiency and risk of dental caries among young children: A public health problem. Indian J Oral Sci 2013;4:75-82
|How to cite this URL:|
Bener A, Al Darwish MS, Hoffmann GF. Vitamin D deficiency and risk of dental caries among young children: A public health problem. Indian J Oral Sci [serial online] 2013 [cited 2019 May 25];4:75-82. Available from: http://www.indjos.com/text.asp?2013/4/2/75/119937
| Introduction|| |
Vitamin D deficiency remains a major health problem in greater parts of the world, ,,,,,,,, including Africa,  the Middle East ,,,,,,,, and the Indian sub-continent.  As a matter of facts, several studies have shown vitamin D deficiency to be a global public health problem.  Many of the studies reported a high prevalence of vitamin D deficiency as a result of restricted sunlight exposure and inadequate vitamin D intake in children in developed as well as developing countries. ,,,,,,,,,,, Infantile vitamin D deficiency is common in the Arab/South Asian countries including Lebanon,  Qatar ,,,, India,  Kuwait  and Japan. ,,,,,,,, Also, in the UK, there has been a resurgence of vitamin D deficient rickets among toddlers and the reports of adolescents presenting with symptoms of vitamin D deficiency.  Prolonged breast-feeding without vitamin D supplementation, maternal vitamin D deficiency and limited sunshine exposure have been suggested as a major risk factors. ,,,,,, Vitamin D status in childhood and adolescence may also play an important role in the prevalence of dental caries. ,[4.11],,, An adequate status may reduce the risk of adult diabetes, ischemic heart disease, hypertension and tuberculosis. 
Dental caries remains an important problem of oral health in many communities, particularly among the underprivileged groups in developed as well as developing countries. ,,,, Several studies have reported that culture and age cohort, as well as language and economic limitations, act as barriers to an ethnic minority obtaining dental care and maintaining good oral health.  In the literature, the prevalence of dental caries experience has been associated with many factors, such as low socioeconomic status, restricted access to dental services, sugar consumption, parents' instruction, tooth-brushing frequency, fluoride intake and regular dental appointments. ,,,, The exact mechanism for vitamin D and dental carries prevention is not fully understood; however, it is proposed that it work through enhancing calcium metabolism  and the induction of the antimicrobials cathelicidins and defensins thereby attacking the oral bacteria linked to dental carries. ,,
However, no data have been reported regarding dental caries and associated vitamin D deficiency as a risk factor in Middle East, Africa and the Asian continent. Therefore, the aim of the present study was to determine the prevalence of vitamin D deficiency and possible association between vitamin D levels and carries experience among the young children's in Qatar.
| Subjects and Methods|| |
This is a cross-sectional study in the young Qatari population aged 7-16 years old. The survey was conducted over a period from August 2009 to June 2010. The study was approved by the Hamad General Hospital, Hamad Medical Corporation. All the human studies have been approved by the Research Ethics Committee and have therefore been performed in accordance with the ethical standards laid down in the 1964 Declaration of Helsinki. The declaration includes principles on: Safeguarding research subjects; informed consent; minimizing risk and adhering to an approved research plan/protocol. The Declaration is considered as a fundamental document in the ethics of health-care research. All the parents of children who agreed to participate in this study gave their informed consent prior to their inclusion in the study.
Selection of subjects
The children were selected through two-stage cluster random sampling technique. Initially, 13 Primary Health-Care Centers (PHCs) were randomly selected out of total 21 PHCs followed by random selection of the male and female Qatari children age 7-16 years, who visited the selected PHCs for any reason other than acute or chronic disease. A sample of 1,752 apparently healthy children was approached and parents of 1249 children expressed their consent to participate in this study with a response rate of 71%. The remaining 503 children were excluded from the study either because of refusal from their parents or an incomplete questionnaire or did not have vitamin D lab value.
Data collection methods
The survey involved a structured questionnaire followed by an oral examination, measurements of height and weight and laboratory investigation. The completion of the questionnaire and the clinical examination were conducted on the same day. The clinical examination assessed the dentition status and was based on the methods and criteria described by the World Health Organization. , Furthermore, the study provides a number of decayed teeth (DT), missing teeth (MT), filled teeth (FT) and decayed missing and filled teeth (DMFT) of the participants.
Visual inspection was used for the registration of dental caries experience and the clinical examinations were carried out in daylight using a plane mouth mirror. The study was performed by 5 examiners per day. On the average, 30-35 students were examined per day.
For biochemical assessment of vitamin D, the immunochemical method was used. Venous blood samples were collected into plain tubes, serum was separated and stored at-70°C until analysis. 25(OH) D was estimated using a kit DiaSorin/the Diagnostic Specialist (DiaSorin Corporate Headquarter, Saluggia (Vercelli), Italy). The treated samples were then assayed using a competitive binding radioimmunoassay technique. Serum levels of these biochemical parameters were determined according to the standard laboratory procedures. Subjects were classified into three categories: Severe vitamin D deficiency which is defined as a serum level of 25-hydroxy vitamin D (25(OH) D) below 10 ng/ml. Mild to moderate deficiency is defined as serum 25(OH) D between 10 and 20 ng/ml and optimum levels between 20 and 80 ng/ml. ,,,,,
The survey was based on the standardized interviews performed by a trained health professionals and dental assistants. The parents of the participants were interviewed concerning socio-demographic information of both the parent and child such as age, gender, educational level, occupation, place of residence (urban and or semi-urban), type of housing, monthly income and consanguinity. Furthermore, it included assessment of non-dietary variables such as height, weight, color of the skin, family history, physical activity and duration of exposure to sunlight. Height and weight were measured using standardized methods and all the participants wore light clothes and no shoes for this part of the examination. The body mass index (BMI) was calculated as weight in kilograms (with 1 kg subtracted to allow for clothing) divided by height in meters squared. Furthermore, information was obtained on vitamin D intake and the feeding pattern during infancy.
The questionnaire and criteria for vitamin D deficiency in the young population were defined and developed by the primary investigator. A translated Arabic version of the questionnaire was back translated by a bilingual consultant. The survey instrument was first tested on 100 randomly selected healthy subjects from the children visiting Primary Health-Care clinics. Content validity, face validity and reliability of the questionnaire were tested using 100 children. These tests demonstrated a high level of validity and a high degree of repeatability (κ =0.84).
The mean number of decayed, missing and filled permanent teeth (DMFT) and percentage of caries experience-free children (DMFT = 0) was calculated. Student t-test was used to ascertain the significance of differences between mean values of two continuous variables and the nonparametric Mann-Whitney test was used as appropriate. Chi-square analysis was performed to test the differences in proportions of categorical variables between two or more groups. In 2 × 2 tables, the Fisher's exact test (two-tailed) replaced the Chi-square test if the assumptions underlying Chi-square were violated, namely in case of small sample size and where the expected frequency was less than 5 in any of the cells. We used multivariable Poisson regression models to determine the predictors of carries experience after adjusting for possible confounders like age and gender. The level P < 0.05 was considered as the cut-off value for significance.
| Results|| |
[Table 1] provides mean number of DT, MT, FT and DMFT across different socio-demographic and anthropometric characteristics of the participants. The mean number of FT was significantly higher among the age group of 10-13 years as compare to 7-10 years. DT, MT and DMFT were not significantly different across the different age groups. Similarly, children of housewives were having significantly higher mean numbers of DMFT than children of business women (Mean [standard deviation (SD)] 4.73; [0.23]; vs. 2.68; [0.61]; P < 0.05] [Table 1]. Mean DT and MT was not significant different across children with different maternal occupations. Children with household income ≥3000 US$ were having significantly higher mean numbers of MT (Mean [SD] 0.37 [0.03]), FT (Mean [SD] 0.91 [0.05]) and DMFT (Mean [SD] 4.65 [0.13]) as compared to <3000 US$.
|Table 1: Mean caries indices across socio-demographic and anthropometric characteristics of children in Qatar (N=1,249)|
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[Table 2] presents mean number of DT, MT, FT and DMFT across clinical, biochemical and dental care characteristics of the participants in Qatar. Mean (SD) number of DT (2.77 [0.11] vs. 3.41 [0.11]), MT (0.07 [0.02] vs. 0.65 [0.04]), FT (0.19 [0.03] vs. 1.64 [0.07] and DMFT (3.08 [0.13] vs. 6.12 [0.19]) were significantly lower (P < 0.05) among children with optimum levels of serum vitamin D as compared to those with deficient serum vitamin D. Except DT, there were no differences in mean numbers of MT, FT and DMFT between children with optimum and deficient serum calcium levels. Children with family history of diabetes mellitus were also having significantly higher mean (SD) number of MT (0.47 [0.04] vs. 0.27 [0.03]; P < 0.05), FT (1.22 [0.08] vs. 0.68 [0.05]; P < 0.05) and DMFT (5.11 [0.21] vs. 4.20 [0.15]; P < 0.05] as compare to children with a negative family history. In addition, children with family history of vitamin D deficiency were having significantly higher mean (SD) number of DT (3.40 [0.14] vs. 2.90 [0.10]; P < 0.01), MT (0.45 [0.04] vs. 0.29 [0.03]; P < 0.01], FT (1.14 [0.08] vs. 0.73 [0.05]; P < 0.01] and DMFT (5.28 [0.22] vs. 4.13 [0.14]; P < 0.01) as compare to children without a family history of vitamin D deficiency. Children who reported brushing their teeth after each meal or twice a day were having significantly lower mean number of DMFT as compared to those who brushed their teeth once a week (P < 0.01). There was no significant difference in the mean number of DMFT between children who cleaned their teeth once a day or once a week (P > 0.05).
|Table 2: Mean caries indices across clinical, biochemical, and reported dental cure health habits among children in Qatar (N=1,249)|
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[Table 3] shows predictors of dental caries experience based on the univariable Poisson regression analysis. Being female, BMI > 95 th percentile as compare to <85 th percentile, household income ≥3000 US$ as compare to <3000, parental consanguinity, deficient level of serum vitamin D and calcium, tooth brushing once a week and family history of vitamin D deficiency were all significantly associated with a number of dental caries among children in Qatar.
|Table 3: Univariate analysis of predictors for dental caries among children in Qatar (N=1,249)|
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[Table 4] presents an adjusted risk ratio for the predictors of dental caries experience based on a multivariable Poisson regression analysis. Children with deficient levels of serum vitamin D were 1.13 times more at risk of dental caries as compared to those with optimum serum vitamin D (adjusted RR: 1.13; 95% CI: 1.05-1.21; P < 0.01) while adjusting for all potential confounders in the model. Similarly, the risk of dental caries was 1.12 times (95% CI: 1.05-1.21) higher among female children as compared to male wile adjusting for all other potential confounders in the model. In addition, deficient level of serum calcium was also independently associated with the number of dental caries (adjusted RR: 1.21; 95% CI: 1.11-1.31; P < 0.01). There was an inverse relationship between frequency of tooth brushing and risk of dental caries. The risk of dental caries among children with brushing once a week, once a day and twice a day were 1.58 times, 1.01 times and 0.98 times respectively as compared to those who brush their teeth after each meal while adjusting for all other potential covariates. The risk of dental caries was also significantly higher among children of non-consanguineous parents as compared to those of consanguineous parents (adjusted RR: 1.10; 95% CI: 1.01-1.19; P = 0.025).
|Table 4: Multivariable poisson regression analysis of predictors for dental caries among children in Qatar (N=1249)|
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| Discussion|| |
The present study was focusing on Qatari children between 7 and 16 years of age revealed that vitamin D deficiency is highly prevalent in this population. 47.5% of the Qatari children were identified with vitamin D deficiency, this percentage increasing with age and being most prominent in the age group ,,, years old (48.8%). The current study demonstrated an increasing vitamin D deficiency in the rapid growth period of adolescent children and clearer guidelines for its prevention including an increased awareness, especially in older children and at risk groups based on these findings need to be devised and be more widely accessible. A study conducted in Lebanon  showed that vitamin D deficiency is common among young Lebanese people (72.8%) which are even higher than the rate found in Qatar. A similar rate of vitamin D deficiency (74%) was reported by Alemzadeh et al. among children and adolescents. Vitamin D status is highly different in various countries of Europe ,,,,,,,, and in the Middle East. ,,,,, A recent study has demonstrated a high prevalence of vitamin D insufficiency (35%) amongst UK children.  The Euronat Seneca study showed that vitamin D deficiency was surprisingly much more common in people living in sunny countries like Italy, Spain and Greece than among those living in countries in which sunshine exposure is considered relatively insufficient Absoud et al.  Similarly, the current study demonstrated a high prevalence of vitamin D deficiency in Qatar, despite the fact that Qatar can be considered a very sunny country with ample sunlight throughout the year. In many populations, there are conflicting concerns: On one hand there are concerns about the hazards and consequences of an excessive sun exposure and on the other hand, there are concerns about current lifestyles with inadequate sun exposure leading to vitamin D deficiency.
The present study assessed the factors associated with prevalence of dental caries in 7-16 years-old Qatari's schoolchildren. The caries prevalence, DMFT index and percentage of caries-free children observed in this population were similar to the data reported in Japanese children. , However, when compared to data of Brazilian children living in Brazil, , the caries prevalence and DMFT index were lower and the percentage of caries-free children was higher. The results are in agreement with those of a previous study, which also observed a low prevalence and severity of dental caries in Brazilian school children, , aged 6-12 years old, residing in Japan. 
Literature regarding the correlation between sugar consumption and dental caries is inconclusive. Some reported that changes in sugar consumption are currently responsible for social inequalities in dental caries prevalence. Reduction of caries prevalence may be related due to distinct dental health factors, such as use of fluoride dentifrice, frequency of tooth brushing and access to dental-care services. , Other authors suggest that a sugary diet still represents a dominant caries risk factor,  because fluoride use is not widespread among immigrant and ethnic groups whose dental knowledge is often poor. The pattern of use of sugar has also changed in recent years, from consumption of pure sugar to an increased intake of sweets and chocolates. ,, Scientists from world-wide agree on the importance of regular use of fluoride to control dental caries.  Brazilian school children residing in Japan do not have access to fluoridated water supply nor dietary fluoride supplements, because systemic fluorides are not used domestically. ,
The present study assessed the association between vitamin D deficiency levels and dental caries while adjusting for potential confounders among 7-16 years-old schoolchildren in Qatar. Dental caries is a multi-factorial disease. The interplay between biological and social risk factors was highlighted in the present study, in which the mother's schooling educational level and previous access to dental care services in Qatar were associated with dental caries in a population of Qatari's school children residing in Doha and sub-urban areas. The health indicators and socio-economic status have shown, in general, a directly proportional relationship; the lower the socio-economic status, worse the health indicators. ,,,, Among the various possibilities for the use of socio-economic indicators, the level of maternal schooling has been used as one of the best predictors of a child's health, mainly in underdeveloped countries. ,,,, The results of this study indicated that children with lower educational level mothers experienced more caries than children with higher educational level mothers. Our results are in agreement with other previous studies which showed that the degree of schooling of the child's guardian, especially the level of schooling of the mother, appears to be a risk factor for dental caries in children. ,,,,,,,,,,,,,,,,,, More access to information, better understanding of the importance of dental health in daily life and better oral hygiene could explain these findings in a population with more years of study. A cross-sectional descriptive study was performed in Saudi Arabia (37) among 1115 students reported that the clinically decayed tooth was diagnosed in 68.9% of the included children, more in urban and younger students. Caries affected the subjects consumed carcinogenic foods at greater frequency compared with caries-free children. Only 24.5% of the students brushed their teeth twice or more per day and 29% of them never received instructions regarding oral hygiene practices. The poor oral hygiene practices in Saudi Arabia showed that lack of parental guidance and appropriate dental health knowledge with frequent exposure to carcinogenic foods in addition to socio-demographics are the main risk factors for dental decay among the surveyed students.
The current data revealed that vitamin D deficiency was higher among Qatari girls (51.4%) as compared to boys (48.6%). A similar finding was reported by other studies that in Italy, vitamin D deficiency is also wide-spread among children and adults of both sexes, but more so in females  and in Saudi Arabia.  Our result is similar to what is observed in European countries in Norwegian,  in Italy,  in the United States  and another sun-rich country like Lebanon  vitamin D deficiency is common among healthy adolescent girls, with non-white girls being the most severely affected.
Prevalence of dental caries was 59% (95% CI: 56.7-61.3) among those with deficient levels of vitamin D as compared to those with optimum levels of vitamin D (41%; 95% CI: 38.7-43.3) in this study. Furthermore, the duration of time spent outdoors was very low in dental caries children as compared to those without dental caries. This shows that a major reason for vitamin D deficiency might be due to lack of sun exposure, which appears to be a main factor and problem in the dental caries children. In fact, the effect of seasonal sunlight exposure on vitamin D status has been well documented, , confirming the importance of sun exposure in the synthesis of vitamin D. Exposure to sunlight is thought to provide most of the vitamin D requirement of the human population. Thus, very limited exposure to sunlight might be a potential cause of vitamin D deficiency resulting in dental caries among children in Qatar.
| Conclusion|| |
Prevalence of dental caries is high among children with vitamin D deficiency in Qatar. Vitamin D deficiency was identified as an important causative factor. In addition, gender, frequency of tooth brushing, household income and family history of vitamin D deficiency were some of the significant predictors of dental caries among children in Qatar. This study provides dentists with some evidence to guide their clinical decisions inform future public health preventative strategies and help the design of future studies.
| Acknowledgment|| |
This study was generously supported and funded by the Qatar National Research Fund-[QNRF] NPRP 08-760-3-153. The authors would like to thank the families, health professionals and dental assistants, who participated in the study and the Hamad Medical Corporation for their support and IRB ethical approval (HMC MRC #11060/11).
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[Table 1], [Table 2], [Table 3], [Table 4]