Maternal vitamin D status in Type 1 diabetic pregnancy: Impact on neonatal vitamin D status and association with maternal glycaemic control

Abstract

Objective: The first aim of this study was to assess 25-hydroxy vitamin D (25OHD) concentrations in women with type 1 diabetes (T1DM) during pregnancy, post-delivery and also foetal (cord blood) 25OHD concentrations and to examine relationships between these. The second aim of the study was to investigate potential interactions between maternal body mass index (BMI) and foetal vitamin D status. A further study aim was to examine potential relationships between maternal 25OHD and glycosylated haemoglobin (HbA 1c ) throughout pregnancy. Research Design and Methods:This was an observational study of 52 pregnant controls without diabetes and 65 pregnant women with T1DM in a university teaching hospital. Maternal serum 25OHD was measured serially throughout the pregnancy and post-delivery. Cord blood 25OHD was measured at delivery. 25OHD was measured by liquid chromatography tandem mass spectrometry (LC-MS/MS).Results: Vitamin D deficiency (25OHD ,25 nmol/L) was apparent in both the T1DM subjects and controls at all 3 pregnancy trimesters. Vitamin D levels in all cord blood were ,50 nmol/L. Maternal 25OHD correlated positively with cord 25OHD at all 3 trimesters in the T1DM group (p = 0.02; p,0.001; p,0.001). 25OHD levels within cord blood were significantly lower for women with diabetes classified as obese vs. normal weight at booking [normal weight BMI ,25 kg/m 2 vs. obese BMI .30 kg/m 2 (nmol/L6SD); 19.93611.15 vs. 13.7364.74, p = 0.026]. In the T1DM group, HbA 1c at booking was significantly negatively correlated with maternal 25OHD at all 3 trimesters (p = 0.004; p = 0.001; p = 0.05). Conclusion:In T1DM pregnancy, low vitamin D levels persist throughout gestation and post-delivery. Cord blood vitamin D levels correlate with those of the mother, and are significantly lower in obese women than in their normal weight counterparts. Maternal vitamin D levels exhibit a significant negative relationship with HbA 1c levels, supporting a potential role for this vitamin in maintaining glycaemic control.

Serum 25‐hydroxyvitamin D and insulin resistance in people at high risk of cardiovascular disease: a euglycaemic hyperinsulinaemic clamp study

“… Lipids were measured using a standard enzymatic colorimetric assay, and serum calcium, phosphate and albumin were measured using a photometric method on an automated Roche Cobas 8000 Modular system biochemical analyser (Roche Diagnostics, West Sussex, UK). Serum concentrations of 25‐OHD 2&3 were measured by means of liquid chromatography–tandem mass spectrometry (LC‐MS/MS) and results were presented as total 25‐OHD …”

“…Serum concentrations of 25-OHD 2&3 were measured by means of liquid chromatography-tandem mass spectrometry (LC-MS/MS) and results were presented as total 25-OHD. 19…”

Assessment of vitamin D levels in type 1 and type 2 diabetes patients: Results from metaanalysis

“…Altogether, 12 studies were included in the analysis of the 25(OH)D levels in T1D patients . Table summarized the main studies and patients characteristics.…”

“…The potentially relevant references were identified by reviewing titles and/or abstracts, and/or full text of all citations identified with database searches. Out of 763 initial hits, 12 and 11 eligible studies were finally included in the metaanalysis of vitamin D levels in T1D and T2D patients, respectively. Ten studies were excluded for not providing exact standard deviation values of serum 25(OH)D levels in T1D or T2D patients .…”

Immunological characterisations of peripheral blood memory CD4+ T cells in children with type 1 diabetes, their non-diabetic siblings and age- and gender-matched unrelated healthy control children

“…In addition, maternal vitamin D deficiency may also increase the risk of T1D in off-springs [32]. It has been suggested that vitamin D may contribute to immune modulation and thereby protect or arrest an ongoing immune activations [31].…”