Serum 25-Hydroxyvitamin D Concentrations at Birth in Children Screened for HLA-DQB1 Conferred Risk for Type 1 Diabetes

Abstract

Context Vitamin D has several effects on the immune system that might be of relevance for the pathogenesis of type 1 diabetes (T1D). Objective To evaluate whether umbilical cord serum concentrations of 25-hydroxy-vitamin D (25[OH]D) differ in children developing either islet autoimmunity (IA) or overt T1D during childhood and adolescence. Design Umbilical cord serum samples from 764 children born from 1994 to 2004 with HLA-DQB1 conferred risk for T1D participating in the Type 1 Diabetes Prediction and Prevention Study were analyzed for 25(OH)D using an enzyme immunoassay. Setting DIPP clinics in Turku, Oulu, and Tampere University Hospitals, Finland. Participants Two hundred fifty children who developed T1D diabetes at a median age of 6.7 years (interquartile range [IQR] 4.0 to 10.1 years) and 132 additional case children who developed IA, i.e., positivity for multiple islet autoantibodies. Cases were matched for date of birth, gender, and area of birth with 382 control children who remained autoantibody negative. The median duration of follow up was 9.8 years (IQR 5.7 to 13.1 years). Main Outcome Measure The median 25(OH)D concentrations. Results The median 25(OH)D concentration in cord serum was low [31.1 nmol/L (IQR 24.0 to 41.8); 88% <50 nmol/L], but not statistically different between children who developed T1D or IA and their control groups ( P = 0.70). The levels were associated mainly with geographical location, year and month of birth, age of the mother, and maternal intake of vitamin D during pregnancy. Conclusions The 25(OH)D concentrations at birth are not associated with the development of T1D during childhood.

Serum 25-hydroxyvitamin D concentration in childhood and risk of islet autoimmunity and type 1 diabetes: the TRIGR nested case–control ancillary study

“…Our results do not support a strong role for vitamin D in the disease process leading to type 1 diabetes. This is consistent with results from the DIPP and DAISY birth cohort studies [2][3][4]. Recent findings suggest that vitamin D deficiency may be a risk factor for those carrying certain genotypes of the VDR gene [5,13].…”

“…Large birth cohort studies that have invited participants based on an increased genetic risk for type 1 diabetes have analysed the association between serum 25OHD concentration and type 1 diabetes. The Finnish Diabetes Prediction and Prevention (DIPP) study [2,3] and the Diabetes Auto Immunity Study in the Young (DAISY) [4] did not find any association between serum 25OHD concentration and risk of islet autoimmunity or type 1 diabetes at birth or during childhood, whereas the Environmental Determinants of Diabetes in the Young (TEDDY) study reported an association between low serum 25OHD concentration during childhood and increased risk of islet autoimmunity [5]. A Norwegian study found an association between maternal low serum 25OHD concentrations and increased risk for type 1 diabetes in the offspring [6], whereas in Finland such an association was not seen in a similar study setting [7].…”

Vitamin D Metabolites and Binding Protein Predict Preeclampsia in Women with Type 1 Diabetes

“…By contrast, 25(OH)D, the standard metric for vitamin D, did not predict PE; of note, however, insufficient or deficient levels were almost universal in our diabetic cohort. Reported associations of vitamin D deficiency in diabetic pregnancy include preterm birth, increased T1DM rates in offspring of women with T1DM, and poor glycemic control [12,17,20,21,29]. Some studies in non-diabetic pregnant women have suggested that low total 25(OH)D is associated with contemporaneous [10] or subsequent PE [9,12], perhaps limited to early-onset disease [13].…”

“…In the general population, the plasma concentration of 25-hydroxyvitamin D (25(OH)D), the prohormone and precursor of 1,25(OH) 2 D, is considered the principal metric for assessing vitamin D status: deficiency and insufficiency are defined as <20 and <32 ng/mL (<50 and <80 nmol/L), respectively [7]. Vitamin D deficiency is associated with poor pregnancy outcomes for both mother and child [2,[8][9][10][11][12][13][14][15][16][17][18][19][20][21]. Both 25(OH)D and 1,25(OH) 2 D can be measured in plasma as total, bioavailable, and free forms; both metabolites are highly lipophilic and, in plasma, are almost entirely protein-bound.…”

Prediction and Prevention of Type 1 Diabetes

“…This could explain the reported controversial results. A recent study shows that the integration of vitamin D with ω-3 co-supplementation and arachidonic acid reduction in the Mediterranean diet have benefits for T1D children at onset (40 (41). Although these results add relevant information on the risk of T1D, other components still need to be evaluated.…”