Introduction: Vitamin D (VitD) has been shown to impact neurodevelopment. Studies have shown that higher 25-hydroxy-vitamin D (25(OH)D) concentrations (the indicator of vitD status) may be associated with better neurodevelopmental outcomes, although current data are conflicting. This study examined the relationship between total circulating 25(OH)D concentrations and neurodevelopmental outcomes in 3–5-year-old (3–5 yo) children. Methods: In this study, pregnant women were randomized to receive 400 (standard dose), 2000, or 4000 IU vitD₃/day. Offspring then underwent the Brigance Screen at 3–5 yo. The 25(OH)D concentration was measured at birth and 3–5 yo. Relationships between Brigance scores and 25(OH)D and Brigance scores and vitamin D binding protein (VDBP) genotype were examined. Results: Higher 25(OH)D at the time of testing was associated with better overall performance on neurodevelopmental testing as measured by the Brigance quotient (B = 0.208, p = 0.049). Scores were then broken down into sub-scores. Children born to mothers in the 2000 IU/day group scored higher on the Brigance language component of the assessment versus the standard dose group (B = 4.667, p = 0.044). The group of children who had the Gc1f-1s or Gc1f-2 genotypes scored higher on the Brigance academic component (B = 9.993, p < 0.001) and lower on the Brigance language component versus the 1f1f genotype (B = −9.313, p < 0.001). Children with the Gc1s-1s, Gc1s-2, or Gc2-2 genotypes also scored lower than the Gc1f-1f genotype (B = −6.757, p = 0.003). Conclusion: These results suggest that higher 25(OH)D concentrations early in life and higher doses of maternal vitamin D supplementation during pregnancy may have a positive association with neurodevelopmental outcomes. This study also suggests that the VDBP genotype is associated with neurodevelopment and differentially affects various fields of neurodevelopment.

The objective of this investigation was to compare bioavailability between single oral dose Vitamin D₃ (vitD₃) gummies vs. tablets in healthy adults. An initial crossover, randomized clinical trial involving healthy adults (n = 9) was conducted followed by a larger, confirmatory study (n = 31). Healthy participants aged 18–45 years with body mass index (BMI) 18–30 without anemia or vitD deficiency were randomized to receive 20,000 international units (IU) vitD₃ as single dose gummies or tablets with serial samples obtained to measure plasma vitD₃ at baseline, 3, 6, 10, 24, and 48 h followed by a 2-week washout period. The same participants then crossed over to receive 20,000 IU vitD₃ in the form not previously given, with sampling at the same time points. Deidentified blood samples were analyzed for vitD₃ concentration by liquid chromatography (LC)-mass spectroscopy. In Study 1, results suggested bioavailability was greater with gummies compared with tablets, (effect size 1.08 at 24 h). In Study 2, the area under the concentration curve (AUC) was higher with gummies than tablets (gummy mean (95% CI): 1474 ng·/mL (1393–1555); tablet mean (95% CI): 774 ng·h/mL (693–855), p < 0.0001). Average peak blood concentration (C_max) values were significantly higher with gummies (gummy: 47.3 ng/mL; tablet: 23.4 ng/mL; p < 0.0001). VitD₃ gummies had greater bioavailability than tablets with higher vitD concentrations over time, which may have implications for achieving vitD sufficiency.

The risk for preeclampsia (PE) is enhanced ~4-fold by the presence of maternal type 1 diabetes (T1DM). Vitamin D is essential for healthy pregnancy. We assessed the total, bioavailable, and free concentrations of plasma 25-hydroxyvitamin D (25(OH)D), 1,25-dihydroxyvitamin D (1,25(OH)₂D), and vitamin D binding protein (VDBP) at ~12, ~22, and ~32 weeks’ gestation (“Visits” (V) 1, 2, and 3, respectively) in 23 T1DM women who developed PE, 24 who remained normotensive, and 19 non-diabetic, normotensive women (reference controls). 25(OH)D deficiency was more frequent in diabetic than non-diabetic women (69% vs. 22%, p < 0.05), but no measure of 25(OH)D predicted PE. By contrast, higher 1,25(OH)₂D concentrations at V2 (total, bioavailable, and free: p < 0.01) and V3 (bioavailable: p < 0.05; free: p < 0.01), lower concentrations of VDBP at V3 (p < 0.05), and elevated ratios of 1,25(OH)₂D/VDBP (V2, V3: p < 0.01) and 1,25(OH)₂D/25(OH)D (V3, p < 0.05) were all associated with PE, and significance persisted in multivariate analyses. In summary, in women with T1DM, concentrations of 1,25(OH)₂D were higher, and VDBP lower, in the second and third trimesters in women who later developed PE than in those who did not. 1,25(OH)₂D may serve as a new marker for PE risk and could be implicated in pathogenesis.

It is unknown if vitamin D (vitD) sufficiency in breastfeeding mothers can lead to physiological outcomes for their children that are discernible from infant vitD sufficiency per se. In a 3-month, randomized vitD supplementation study of mothers and their exclusively breastfeeding infants, the effects of maternal vitD sufficiency were determined on infant plasma concentrations of 25-hydroxyvitamin D (i.e., vitD status) and 11 cytokines. An inverse correlation was seen between maternal vitD status and infant plasma TNF concentration (r = −0.27; p < 0.05). Infant whole blood was also subjected to in vitro antigenic stimulation. TNF, IFNγ, IL-4, IL-13, and TGFβ1 responses by infant leukocytes were significantly higher if mothers were vitD sufficient but were not as closely correlated to infants’ own vitD status. Conversely, IL-10 and IL-12 responses after antigenic challenge were more correlated to infant vitD status. These data are consistent with vitD-mediated changes in breast milk composition providing immunological signaling to breastfeeding infants and indicate differential physiological effects of direct-infant versus maternal vitD supplementation. Thus, consistent with many previous studies that focused on the importance of vitD sufficiency during pregnancy, maintenance of maternal sufficiency likely continues to affect the health of breastfed infants.

Background/Objectives: Stress during pregnancy critically impacts maternal and fetal health. While prior research has linked sociodemographic and biological factors to stress levels, the role of specific biomarkers, such as vitamin D (VD), remains unexplored. This study examined the relationships among sociodemographic factors, VD status (as measured by serum 25-hydroxyvitamin D [25(OH)D] concentration), and perceived stress in pregnant women. We hypothesized that 25(OH)D concentration would be associated with perceived stress levels during pregnancy. Methods: A post hoc analysis of the Kellogg Pregnancy VD study was conducted on a cohort of 232 pregnant women with Perceived Stress Scale (PSS-10) scores at months 2, 5, and 7 with corresponding 25(OH)D concentrations. PSS-10 scores were classified into two groups: patients with scores of 0–13 were considered to have low stress, while those with scores of 14–40 were considered to have moderate-to-high stress. Logistic regression models identified factors associated with moderate-to-high stress. Results: At month 2, univariate analyses showed that being married (p = 0.002), having a college education (p = 0.0013), and lower BMI (p = 0.018) were associated with lower perceived stress, whereas Black race was associated with higher perceived stress (p = 0.027). By month 7, higher serum 25(OH)D concentration was the only significant predictor of perceived stress in univariate analysis (p = 0.002). In multivariate models at month 7, 25(OH)D approached significance (p = 0.053). Conclusions: Early in pregnancy, race, marital status, college education, and BMI were significantly associated with PSS-10 score. By month 7, 25(OH)D concentration over time emerged as a factor that was significantly associated in univariate analysis and showed a trend toward significance in multivariate models. VD status, as measured by 25(OH)D concentration, may act as a biomarker of stress during pregnancy. Results warrant further study in prospective intervention trials.