Objective: To investigate vitamin D levels and the effect of exogenous vitamin D supplementation in the first trimester among pregnant women in our center. Methods: This was a prospective cohort study. A total of 98 women in the first trimester who were followed-up regularly in Peking Union Medical College Hospital from December 1st 2020 to December 1st 2021 were enrolled. Subjects who had medical conditions that affect vitamin D absorption or metabolism were excluded. Questionnaires were administered, and 25-hydroxyvitamin D [25(OH)D] levels were detected using liquid chromatography tandem mass spectrometry (LC/MS/MS) method. According to the basic 25(OH)D level, different dosages of exogenous vitamin D were supplemented. After 4 weeks, 25(OH)D levels were detected again to evaluate the effect of supplementation. T test, analysis of variance, χ2 test, and multiple linear regression analysis were used for analysis. Results: The mean age of enrolled subjects was (33.5±4.0) years. The baseline 25(OH)D level was (41.2±20.0) nmol/L. Briefly, 70.4% (69/98) subjects were deficient in vitamin D, and 42.9% (42/98) patients were using vitamin D supplementation at the time of 25(OH)D testing. Single-factor analysis showed that vitamin D supplementation (t=-4.21, P<0.001), season (t=2.59, P=0.011), and nut-eating frequency (t=2.67, P=0.009) were related to 25(OH)D levels. Multiple linear regression analysis showed that only vitamin D supplementation had a relationship with 25(OH)D level (B=13.84, P=0.006). According to the baseline 25(OH)D level, 400-5 000 U/d vitamin D3 was supplemented regularly for (4.1±2.5) weeks, and 25(OH)D levels significantly increased after supplementation [(64.1±18.1) vs (37.3±16.6) nmol/L, t=-9.36, P<0.001]. The ascending range was negatively associated with basic 25(OH)D level (B=-0.66, P<0.001) and positively associated with supplementary dosage (B=0.51, P<0.001). 25(OH)D levels increased by 0.51 nmol/L on average per 1 μg (40 U) of vitamin D supplementation daily. Conclusions: The proportion of vitamin D deficiency was high in the first trimester among pregnant women in our center. Exogenous vitamin D supplementation could significantly increase 25(OH)D levels, and the effect was negatively associated with basic 25(OH)D level but positively associated with supplementary dosage.

Vitamin D deficiency has been previously associated with impaired metabolic functions which may impact the acute effects of resistance exercise (RE) on insulin sensitivity, inflammation, and muscle damage. The effects of exogenous vitamin D on the metabolic, inflammatory, and muscle damage responses to an acute bout of RE in vitamin D deficient subjects have yet to be explored. PURPOSE: To evaluate the effects of a single vitamin D3 injection on the metabolic, inflammatory and muscle damage responses to an acute bout of RE in vitamin D-deficient resistance-trained males. METHODS: Blood samples from 14 vitamin D-deficient resistance-trained males were obtained during two separate trials: lower vitamin D (LVD, after saline injection) and higher vitamin D (HVD, after vitamin D3 injection). Metabolic, inflammatory, and muscle damage markers were evaluated at baseline and immediately then one hour after RE. Differences in mean values for each variable between trials were compared by repeated measures ANOVA followed by LSD test for pairwise comparisons. RESULTS: There were significant trial x time interactions for serum insulin and Homeostatic Model Assessment (HOMA) of Insulin Resistance which were both lower (p˂0.05) at 1-hour post-RE in the HVD compared to LVD trial. There was a significant decrease (p<0.05) for blood sugar and increase (p<0.05) for creatine kinase, lactate dehydrogenase, and interleukin 6 1-hour post-RE across both trials with no interaction of time. There were no significant changes in other inflammatory and cardiovascular markers following either trials. A single injection of vitamin D3 demonstrated efficacy in reducing insulin resistance following RE in previously vitamin D-deficient resistance-trained males. Conversely, muscle damage and inflammatory response to acute RE were not altered. CONCLUSION: Intramuscular vitamin D replacement in vitamin D-deficient resistance-trained males may have key implications for the promotion of glucose metabolism and lowering the risk of diabetes in this population.

Background: Vitamin D plays a unique role in promoting embryonic and neural development, cerebral immunological regulation, and influencing neural differentiation and gene regulation. Vitamin D deficiency may be one of the environmental risk factors for autism spectrum disorder. This trial has two purposes: (1) correlating single nucleotide polymorphisms of vitamin D metabolism-related key enzymes to autism susceptibility; and (2) investigating the therapeutic effect of exogenous vitamin D on autism spectrum disorder. Methods/Design: A non-randomized parallel-cohort controlled trial. Sixty children with autism spectrum disorder who receive treatment at the Department of Pediatric Neurological Rehabilitation, First Hospital, Jilin University, China, are included. Sixty healthy controls are also recruited from those undergoing a physical examination. For the first purpose, primary outcomes include vitamin D metabolism and single nucleotide polymorphisms of related genes. Vitamin D level in peripheral blood is the secondary outcome. For the second purpose, 60 children with autism spectrum disorder are treated with exogenous vitamin D supplementation. Prior to and 1 month after exogenous vitamin D supplementation, primary outcomes are evaluated, including the Childhood Autism Rating Scale (CARS) score, Autism Behavior Checklist (ABC) score, the Gesell Developmental Schedules (GDS) score, Clinical Global Impression Scale-(CGI) for severity of illness (SI), global improvement (GI), and efficacy index (EI) scores. Again, vitamin D levels in peripheral blood are evaluated as the secondary outcome. Discussion: This trial is sufficiently powered to provide scientific evidence for the genetic and pathological mechanism of autism spectrum disorder in children that lack vitamin D. Trial registration: Chinese Clinical Trial Registry (http://www.chictr.org.cn/index.aspx) identifier: ChiCTR-TRC-14004499; registered on 30 November 2013. Ethical issues: This trial was approved by the Medical Ethics Committee, First Hospital of Jilin University, China (approval No. 2013-192). The trial protocol will be performed in accordance with the Declaration of Helsinki.

Blood-brain barrier dysfunction characterised by brain parenchymal extravasation of plasma proteins may contribute to risk of neurodegenerative disorders, however the mechanisms for increased capillary permeability are not understood. Increasing evidence suggests vitamin D confers central nervous system benefits and there is increasing demand for vitamin D supplementation. Vitamin D may influence the CNS via modulation of capillary function, however such effects may be indirect as it has a central role in maintaining calcium homeostasis, in concert with calcium regulatory hormones. This study utilised an integrated approach and investigated the effects of vitamin D supplementation, parathyroid tissue ablation (PTX), or exogenous infusion of parathyroid hormone (PTH) on cerebral capillary integrity. Parenchymal extravasation of immunoglobulin G (IgG) was used as a marker of cerebral capillary permeability. In C57BL/6J mice and Sprague Dawley rats, dietary vitamin D was associated with exaggerated abundance of IgG within cerebral cortex (CTX) and hippocampal formation (HPF). Vitamin D was also associated with increased plasma ionised calcium (iCa) and decreased PTH. A response to dose was suggested and parenchymal effects persisted for up to 24 weeks. Ablation of parathyroid glands increased CTX- and HPF-IgG abundance concomitant with a reduction in plasma iCa. With the provision of PTH, iCa levels increased, however the PTH treated animals did not show increased cerebral permeability. Vitamin D supplemented groups and rats with PTH-tissue ablation showed modestly increased parenchymal abundance of glial-fibrillary acidic protein (GFAP), a marker of astroglial activation. PTH infusion attenuated GFAP abundance. The findings suggest that vitamin D can compromise capillary integrity via a mechanism that is independent of calcium homeostasis. The effects of exogenous vitamin D supplementation on capillary function and in the context of prevention of vascular neurodegenerative conditions should be considered in the context of synergistic effects with calcium modulating hormones.

Oxidative processes involved in cryopreservation protocols may be responsible for the reduced viability of tissues after liquid nitrogen exposure. Antioxidants that counteract these reactions should improve recovery. This study focused on oxidative lipid injury and the effects of exogenous vitamin E (tocopherol, Vit E) and vitamin C (ascorbic acid, Vit C) treatments on regrowth at four critical steps of the plant vitrification solution number 2 (PVS2) vitrification cryopreservation technique; pretreatment, loading, rinsing, and regrowth. Initial experiments showed that Vit E at 11-15 mM significantly increased regrowth (P < 0.001) when added at any of the four steps. There was significantly more malondialdehyde (MDA), a lipid peroxidation product, at each of the steps than in fresh untreated shoot tips. Vit E uptake was assayed at each step and showed significantly more alpha- and gamma-tocopherols in treated shoots than those without Vit E. Vit E added at each step significantly reduced MDA formation and improved shoot regrowth. Vit C (0.14-0.58 mM) also significantly improved regrowth of shoot tips at each step compared to the controls. Regrowth medium with high iron concentrations and Vit C decreased recovery. However, in iron-free medium, Vit C significantly improved recovery. Treatments with Vit E (11 mM) and Vit C (0.14 mM) combined were not significantly better than Vit C alone. We recommend adding Vit C (0.28 mM) to the pretreatment medium, the loading solution or the rinse solution in the PVS2 vitrification protocol. This is the first report of the application of vitamins for improving cryopreservation of plant tissues by minimizing oxidative damage.

We evaluated motility and fertilizing ability of rainbow trout Oncorhynchus mykiss semen obtained from fish fed diets without ascorbic acid and a diet supplemented with 870 mg kgminus 1 of ascorbyl monophosphate. Semen was stored in vitro on ice (0 °C) during 14 days. The spermatozoa from the supplemented group had the highest motility and lowest decline in fertilizing ability after storage. Lack of a positive effect of exogenous vitamin C on semen in fish deficient in ascorbic acid (milt was supplemented with 50 mg l−1 of ascorbic acid) suggests that the positive effect of ascorbic acid on semen quality is related to its long-term effects during spermatogenesis.

Studies on the effects of exogenous vitamin A palminate on limb development and regeneration in anuran tadpoles carried out since late 1960s at the author’s laboratory are reviewed and discussed. Most significant was the initial discovery that vitamin A causes regeneration of complete or nearly complete limbs instead of only the missing distal part, thus altering the P-D pattern of regeneration—a phenomenon now called proximalization. Often more than one such regenerates develop per stump. Vitamin A produces proximalizing effect on regeneration cells during their dedifferentiation and blastema formation but inhibits regeneration if given once redifferentiation begins. Shank-level blastemas from treated tadpoles grafted into orbits of previously treated/untreated host tadpoles formed complete limbs. Proximalizing effect is proportionate to vitamin A concentration, duration of treatment, amputational level and stage of tadpoles. Vitamin A produces this effect also if given only prior to amputation. Its influence persists after cessation of treatment, declining with time. Proximalizing effect is correlated with natural ability in limbs to regenerate. Vitamin A improves regenerative ability and can induce it to some extent in non-regenerating limbs. Vitamin A excess retards limb development and produces stage dependent teratogenic defects. Further development of only that limb region is prevented in which differentiation is beginning when vitamin A is given. Short treatment of tadpoles beginning with limbs at spatula/paddle stage inhibited foot development in the unoperated limbs hut promoted regeneration of complete limbs from the contra-lateral amputated limbs. These dual effects were due to cells of the former differentiating and of the latter dedifferentiating when exposed to vitamin A palmitate.

In this study, we investigate the mechanisms of two anomalous protective effects of exogenous vitamin E that had previously been postulated to involve either a specific antioxidant effect or a non-antioxidant function of the vitamin. These atypical vitamin E effects were observed during the prevention of NAD-induced respiratory decline occurring in homogenates and mitochondria prepared from vitamin E- and selenium-deficient rat liver. The study showed neither hypothesis to be true; rather, the two effects, one in homogenates and the other in isolated mitochondria, were explained by other mechanisms. The protective effect against respiratory decline in homogenates was found to result from interference in the thiobarbituric acid assay for lipid peroxidation by ethanol (the conventional solvent for vitamin E addition). With other non-interfering solvents, inhibition of lipid peroxidation by vitamin E, in contrast to previous studies, correlated perfectly with prevention of respiratory decline. The atypical vitamin E effect occurring in isolated mitochondria-and consisting of a requirement for cytosol proteins for the prevention of respiratory decline by exogenous vitamin E-was found to be caused by the prevention of adverse glass effects and not by the action of vitamin E-specific binding proteins. Frequent failures in the combined protective effect of vitamin E and cytosol, which had been a major complication of respiratory decline studies, were found to be caused by phospholipase activity generated during isolation procedures. Irreversible deactivation of respiratory enzymes by lipid peroxidation was found not to be involved in the respiratory decline mechanism.