Serum and urine vitamin D metabolite analysis in early preeclampsia

Abstract

Vitamin D deficiency is common in pregnant women and may contribute to adverse events in pregnancy such as preeclampsia (PET). To date, studies of vitamin D and PET have focused primarily on serum concentrations vitamin D, 25-hydroxyvitamin D3 (25(OH)D3) later in pregnancy. The aim here was to determine whether a more comprehensive analysis of vitamin D metabolites earlier in pregnancy could provide predictors of PET. Using samples from the SCOPE pregnancy cohort, multiple vitamin D metabolites were quantified by liquid chromatography–tandem mass spectrometry in paired serum and urine prior to the onset of PET symptoms. Samples from 50 women at pregnancy week 15 were analysed, with 25 (50%) developing PET by the end of the pregnancy and 25 continuing with uncomplicated pregnancy. Paired serum and urine from non-pregnant women (n = 9) of reproductive age were also used as a control. Serum concentrations of 25(OH)D3, 25(OH)D2, 1,25(OH)2D3, 24,25(OH)2D3 and 3-epi-25(OH)D3 were measured and showed no significant difference between women with uncomplicated pregnancies and those developing PET. As previously reported, serum 1,25(OH)2D3 was higher in all pregnant women (in the second trimester), but serum 25(OH)D2 was also higher compared to non-pregnant women. In urine, 25(OH)D3 and 24,25(OH)2D3 were quantifiable, with both metabolites demonstrating significantly lower (P < 0.05) concentrations of both of these metabolites in those destined to develop PET. These data indicate that analysis of urinary metabolites provides an additional insight into vitamin D and the kidney, with lower urinary 25(OH)D3 and 24,25(OH)2D3 excretion being an early indicator of a predisposition towards developing PET.

Serum 25-hydroxyvitamin D levels throughout pregnancy: a longitudinal study in healthy and preeclamptic pregnant women

“…The observation that 25OHD levels during the first trimester in healthy pregnant women are lower than those of non-pregnant women has previously been described ( 19 , 20 , 21 , 22 ). Holmes et al found that serum 25OHD levels were lower in pregnant women ( n = 98) compared to non-pregnant women ( n = 38) ( P < 0.0001) ( 18 ).…”

“…Even, Khan et al have found a higher prevalence of vitamin D deficiency in pregnant women ( n = 36) than in non-pregnant women ( n = 35) despite being matched by age and same area of residence ( 20 ). Also, Tamblyn et al found lower levels of 25OHD in healthy pregnant women ( n = 25) than in non-pregnant women ( n = 9) ( 21 ). Moreover, Gellert et al showed that 25OHD levels were lower in pregnant women in all trimesters of pregnancy ( n = 429) compared to non-pregnant women ( n = 429) and found an odds ratio (OR) of 13 to develop vitamin D deficiency in pregnant women compared to non-pregnant women ( n = 26) ( 22 ).…”

Gestational hypercalcemia: Prevalence and biochemical profile

“…The placenta has however been suggested to be a major site of CYP24A1 expression and therefore catabolism of 1,25(OH)2D and 25(OH)D and is potentially a source of circulating 24,25(OH)2D. Altered placental vitamin D metabolism and plasma concentrations of vitamin D metabolites have been reported in women with pre-eclampsia (25). Serum 1,25(OH)2D concentrations were above published reference range in non-pregnant adults (36-144 pmol/L ( 16)) in the majority of cases and controls.…”

Vitamin D Measurement, the Debates Continue, New Analytes Have Emerged, Developments Have Variable Outcomes

“…Vitamin D, its metabolites and VDBP have been detected and measured in a wide range of human tissues and bodily fluids, other than plasma. These include breast milk, urine, semen, saliva, cerebrospinal and synovial fluid, skin and muscle biopsies and hair samples [89][90][91][92][93][94]. The collection of such samples may provide benefits, such as ease of sample collection and avoidance of invasive sampling methods or for the investigation of organ-specific aspects of vitamin D metabolism and function.…”