الفهرس 
Vitamin DOnly 14 pages are availabe for public view
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Abstract
Gestational diabetes mellitus (GDM), defined as carbohydrate intolerance causing hyperglycaemia with first onset in pregnancy after 20 weeks gestation, is increasing in incidence in many populations worldwide as obesity becomes more prevalent.
The epidemic of diabetes poses an enormous public health challenge globally. Given the adverse impacts of GDM on pregnancy outcomes, perinatal morbidity, and development of chronic diseases including T2DM later in life, increasing attention has been drawn to the increasing prevalence of this common pregnancy complication.
Screening and diagnosis of GDM and treating it effectively not only prevent adverse maternal and perinatal outcome but also future diabetes in both mother and child.
Vitamin D is the sunshine vitamin that has been produced on this earth for more than 500 million years. During exposure to sunlight 7-dehydrocholesterol in the skin absorbs UV B radiation and is converted to previtamin D3 which in turn isomerizes into vitamin D3.
Vitamin D is metabolized sequentially in the liver and kidneys into 25-hydroxyvitamin D which is a major circulating form and 1,25-dihydroxyvitamin D which is the biologically active form respectively. 1,25-dihydroxyvitamin D plays an important role in regulating calcium and phosphate metabolism for maintenance of metabolic functions and for skeletal health.
There has recently been significant attention paid to aspects of health associated with vitamin D and the wide range of health factors linked to deficiency. The growth in interest has been widespread with extensive coverage in popular media sources and academic literature.
The placenta on the other hand, is an organ vital for the maintenance of a healthy pregnancy and plays a crucial role in developmental fetal programming. The decidua facilitates nutritional fetal-maternal exchange and serves as an endocrine tissue by secreting a plethora of bio molecules, also providing “immunological stability and tolerance” to accommodate the developing fetus.
Vitamin D deficiency has been defined as a 25(OHD) level less than 20 mg/ml (50 nmol/l) while vitamin D insufficiency is defined as a 25(OHD) level between 21 and 29 ng/ml (52–72 nmol/l). It is a fact that vitamin D deficiency varies by age group; therefore, there are certain controversies in regards of the standardized level for identifying deficiencies.
Beyond its classical function as a regulator of calcium and phosphate metabolism, vitamin D elicits numerous effects in the human body. Current evidence highlights a vital role of vitamin D in mammalian gestation. During pregnancy, adaptations in maternal vitamin D metabolism lead to a physiologic increase of vitamin D levels, mainly because of an increased renal production, although other potential sources like the placenta are being discussed. A sufficient supply of mother and child with calcium and vitamin D during pregnancy ensures a healthy bone development of the fetus, whereas lack of either of these nutrients can lead to the development of rickets in the child.
In addition, vitamin D deficiency has been suggested as a risk factor for glucose intolerance. This is supported by the finding that high-dose, vitamin D supplementation (50,000 IU every 2 weeks) reduces insulin resistance in pregnant women with gestational diabetes.
Studies support that hypovitaminosis D can negatively affect the pregnant woman, among others by inducing gestational diabetes, and therefore can impair fetal growth and abnormal growth effects such as macrosomia. However, other studies have failed to find such relationships, with one study showing no reverse of glucose intolerance with aggressive bolus-dose vitamin D2 supplementation in vitamin D-deficient women at less than 28 weeks’ gestation.
This research aims to study the association between vitamin D deficiency and gestational diabetes through measuring vitamin D level in pregnant women with gestational diabetes and controls without gestational diabetes.
This study is a Case-control study had been conducted in Ain Shams University Maternity Hospital and at Ain Shams immunology laboratories, enrolled 87 women into two groups. The case group with GDM (44 women) and the control group (43 women).
Levels of 25(OH)D in serum had been measured with a commercially available enzyme-linked immunoassay kit for 25(OH)D (EIISA) (CALBIOTECH, Cat VD220B, California). The results were normalized to 25(OH)D levels and expressed in Nanograms per milliliters (ng/ml), and to convert it to nmol/L multiply results by 2.5.
In our study we found that there isn’t a significant relationship between vitamin D level and development of GDM, but there is a mild decrease in vit D level in patients with GDM than control group (2.5+/-1.2 versus 2.9+/-1.5).
We found a very weak correlation between vitamin D level and random blood sugar level in the case group (vitamin D does not affect the blood sugar level in the gestational diabetic women).
We found no statically significant difference between groups according to age, fetal weight, systolic and diastolic blood pressure.
We found a statically significant difference between groups according to gestational age at labour with decreased gestational age at labour in the cases group.
We found a very weak correlation between vitamin D level and age, gestational age, parity, fetal weight, systolic and diastolic blood pressure in the whole sample.
We found that there is no relation between parity, gender of the baby, maternal blood group or Rh and risk of development of GDM.
As regard mode of delivery, we found a significant increased risk of C section in the GDM women but vit D level does not affect mode of delivery.
We found that vit D is not affected by the gender of the baby.
We recommend that it is necessary to give more attention to Vit D and to arrange more studies especially the clinical trials to show the effect of vitamin D administration on various conditions.
In our study all the pregnant women with GDM and without GDM were suffering from vit D deficiency, so we recommend to make vit D supplementation in the regular antenatal care for all pregnant women.