Vitamin D Supplementation in Pregnant Women and Incidence of T1DM in Children: A Cohort Study in Saudi Arabia

Epidemiology of Non-Communicable Diseases
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Title: Evaluation of outcome of vitamin D supplementation in vitamin D deficient
pregnant women on the incidence of Diabetes Mellitus type 1 in children of age between
1 to 4 years in Kingdom of Saudi Aribia
Synopsis:
This study will be planned to find association among vitamin deficiency, vitamin
supplementation and T1DM. It is very necessary to carry out this intervention because fewer
studies are existing for association among vitamin deficiency, vitamin supplementation and
T1DM. In this cohort study 100 women and 100 children will be recruited. This cohort study
will be helpful in identifying exposure-outcome relationship. Influence of socioeconomic
factors and gender on outcome of study will be assessed. Confidentiality will be maintained
for identity of women and children. This study will be carried out in two stages. In first stage,
data will be collected for vitamin D in pregnant women. In second stage, their children will
be assessed for the occurrence of T1DM. Data related to 25OHD levels and vitamin D
supplementation will be gathered from records of hospitals. HPLC and glucose strips will be
used for estimation of HbA1c and glucose levels in children respectively. SPSS statistical
software package version 18.0. will be used for statistical analysis. Potential bias, limitations
and confounding factors will be assessed and proper attention will be given to eliminate these
factors. This cohort study will establish effect of vitamin D deficiency and vitamin D
supplementation on occurrence of TIDM in their children.
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Background:
Vitamin D plays important role in bone health. Deficiency of vitamin D lead to development
of rickets in children and osteomalacia in adults. Deficiency of vitamin D also lead to
development of disease like cardiovascular disease, cancer, autoimmune diseases and type 1
and type 2 diabetes mellitus. In the blood samples, vitamin D can be estimated as 25-
hydroxy vitamin D (25OHD) which is its metabolite. Hypovitaminosis is a condition
associated with vitamin deficiency and it occurs in both pregnant and non-pregnant women.
Factors responsible for the occurrence of hypovitaminosis in children are impaired sunlight
exposure, obesity and latitude (Holick, 2007). Decline in the 25OHD levels in pregnant
women occur with the advanced stages of gestation. Placental barrier is the only delivery
source for supply of vitamin D to foetus. It indicates foetus particularly dependent on mother
for vitamin D. Vitamin D deficiency in mother can result in different conditions in mothers
like pre-eclampsia, gestational diabetes, bacterial vaginosis, pre-term delivery and caesarean
section (Ginde et al., 2010). Moreover, vitamin D deficiency in pregnant women can lead to
development of conditions such as multiple sclerosis, cardiovascular disease, schizophrenia,
certain cancers and other autoimmune diseases such as type 1 diabetes mellitus (T1DM) and
lupus in children. It is evident that vitamin D deficiency can occur between 24 – 28 weeks of
gestation in women with gestational diabetes. 83 % and 29 % of women with gestational
diabetes exhibit 25OHD levels <50 nmol/L and 15 nmol/L respectively (Soheilykhah et al.,
2010; Hossein-Nezhad et al., 2007).
Deficiency of vitamin D can lead to impaired metabolism of glucose and insulin. It can lead
to reduced energy availability to the foetus. Few of the studies indicated that vitamin D lead
to improved insulin sensitivity. However, valid and robust evidence is not available for role
of vitamin D in insulin sensitivity. Most likely reason for the development of TIDM in
children might be due to reduced levels if vitamin D in the children. Hence, pregnant women
should be supplemented with vitamin D. Vitamin D supplementation can lead to improved
insulin sensitivity and it can reach to its optimum level due to vitamin D supplementation on
the regular basis (Alvarez and Ashraf, 2010)
Vitamin D analysis and its correlation with the different health issues is a challenging task.
Challenges associated with the vitamin D are variable actions of vitamin D, ubiquity of
vitamin D receptors in the body and predominant nature of vitamin D deficiency. Hence, it is
necessity to establish robust relationship among these factors. To establish this relationship
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cohort study will be planned. Exposure-outcome relationship will be established in this
cohort study in women from the Kingdom of Saudi Arabia.
Aim:
To reduce occurrence of TIDM in children by supplementation of vitamin D in pregnant
women.
To collect data related to vitamin D deficiency in pregnant women.
To collect data related to vitamin D supplementation in pregnant with vitamin D deficiency.
To estimate HbA1c and glucose levels in children.
To establish relationship between vitamin D supplementation and TIDM in the children.
Hypothesis:
Hypothesis can be stated as :
Vitamin D deficiency in pregnant women can lead to development of T1DM in their children.
Optimum level of supplementation of vitamin D in pregnant women can be helpful in
managing TIDM in their children.
Study design:
In this research, cohort study design will be employed. In this type of study desgn,
participants with the same features are being recruited. In this study, both the current and
historical cohorts will be recruited. This type of cohort studies can be considered as true
prospective studies because in this study data can be collected before the information of the
development of disease (Kung, 2007; Stephen et al., 2013). In the proposed study, vitamin D
deficiency data in the pregnant women will be collected prior to assessment of TIDM in their
children. Common characteristics shared by the participants include pregnant women with
vitamin D deficiency and vitamin D supplementation to these women. In the evaluation
phase, children int the age group 1 – 4 years will be evaluated and these children will be of
the same selected mothers.
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