https://nova.newcastle.edu.au/vital/access/ /manager/Index ${session.getAttribute("locale")} 5 https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:37115 R² = .0140; P = .0082; β = .1075), but not vitamin D₂ levels. It also correlated positively with female adult height (R² = .170; P = .0103; β = .1291) and negatively with the occurrence of female osteoporosis (P = .0495). All data were adjusted for age and gender as appropriate (unadjusted data also provided). From a contemporary perspective, vitamin D levels varied significantly according to season of blood sampling as might be predicted (P = .0009). Conclusions: Increased solar irradiance/UV exposure during the first trimester of pregnancy calibrates adult vitamin D metabolism, which is an important hormone in maintaining calcium balance. This may explain how very early lifecycle UV exposure can influence skeletal development (adult height) and modify risk for the skeletal degenerative disorder osteoporosis. The data demonstrate humans are tuned to the world (exposome) in ways we have not yet fully considered, and which are entrained at the earliest phase of the lifecycle.]]> Wed 19 Aug 2020 11:35:44 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:43197 n = 649) Australian cross-sectional study population. Genetic analysis was used to score vitamin D- and folate-related gene polymorphisms (n = 22), along with two pigmentation gene variants (IRF4-rs12203592/HERC2-rs12913832). Red cell folate and vitamin D₃ were measured by immunoassay and HPLC, respectively. Results: i. Ultraviolet radiation (UVR) and pigmentation genes interact to modify blood vitamin levels; Light skin IRF4-TT genotype has greatest folate loss while light skin HERC2-GG genotype has greatest vitamin D₃ synthesis (reflected in both TOMS and seasonal data). ii. UV-wavelength exhibits a dose–response relationship in folate loss within light skin IRF4-TT genotype (305 > 310 > 324 > 380 nm). Significant vitamin D₃ photosynthesis only occurs within light skin HERC2-GG genotype, and is maximal at 305 nm. iii. Three dietary antioxidants (vitamins C, E, and β-carotene) interact with UVR and pigmentation genes preventing oxidative loss of labile reduced folate vitamers, with greatest benefit in light skin IRF4-TT subjects. The putative photosensitiser, riboflavin, did not sensitize red cell folate to UVR and actually afforded protection. iv. Four genes (5xSNPs) influenced blood vitamin levels when stratified by pigmentation genotype; MTHFR-rs1801133/rs1801131, TS-rs34489327, CYP24A-rs17216707, and VDR-ApaI-rs7975232. v. Lightest IRF4-TT/darkest HERC2-AA genotype combination (greatest folate loss/lowest vitamin D₃ synthesis) has 0% occurrence. The opposing, commonest (39%) compound genotype (darkest IRF4-CC/lightest HERC2-GG) permits least folate loss and greatest synthesis of vitamin D₃. Conclusion: New biophysical evidence supports the vitamin D-folate hypothesis for evolution of skin pigmentation.]]> Wed 14 Sep 2022 09:33:28 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:30416 Wed 11 Apr 2018 17:10:58 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:26544 Wed 11 Apr 2018 15:40:57 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:28251 Wed 11 Apr 2018 14:22:59 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:28948 VDR) polymorphisms, BsmI and ApaI. Methods: Two hundred participants completed food frequency and supplement questionnaires, and were assayed for circulating let-7b expression by qPCR. Polymorphisms were detected using restriction fragment length polymorphism-PCR. Results: let-7b expression negatively correlated with vitamin D intake (r_s = -0.20, p = 0.005). The magnitude and direction of correlation were maintained in the presence of the BsmI restriction site (r_s = -0.27, p = 0.0005). However, in the absence of BsmI restriction site, the direction of the correlation was reversed (r_s = +0.319, p = 0.0497). These correlations were significantly different (z-score = 2.64, p = 0.0085). The correlation between vitamin D intake and let-7a was only significant in those without the ApaI restriction site. Conclusions: The correlation between vitamin D intake and let-7a/b expression in this cohort varies with VDR genotype. This study highlights the importance of considering underlying genotypic variance in miRNA expression studies and in nutritional epigenetics generally.]]> Wed 11 Apr 2018 14:17:40 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:18545 Wed 11 Apr 2018 12:52:16 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:19565 Wed 11 Apr 2018 10:55:18 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:22931 Wed 11 Apr 2018 10:34:32 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:26534 Wed 06 Apr 2022 14:04:50 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:33337 Wed 06 Apr 2022 14:02:17 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:30422 Wed 04 Sep 2019 10:04:44 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:28070 Sat 24 Mar 2018 10:21:27 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:18190 Sat 24 Mar 2018 08:04:22 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:28911 Sat 24 Mar 2018 07:26:00 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:23349 Sat 24 Mar 2018 07:13:33 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:37802 n = 619). Red blood cell folate, 25-hydroxyvitamin D (25(OH)D), and plasma Hcy levels were determined, and genotyping for 21 folate and vitamin D-related variants was performed. Erythemal dose rate accumulated over six-weeks (6W-EDR) and four-months (4M-EDR) prior to clinics were calculated as a measure of environmental UVR. Multivariate analyses found interactions between 6W-EDR and 25(OH)D levels (p_interaction = 0.002), and 4M-EDR and MTHFD1-rs2236225 (p_interaction = 0.006) in predicting Hcy levels. The association between 6W-EDR and Hcy levels was found only in subjects within lower 25(OH)D quartiles (<33.26 ng/mL), with the association between 4M-EDR and Hcy occurring only in subjects carrying the MTHFD1-rs2236225 variant. 4M-EDR, 6W-EDR, and MTHFD1-rs2236225 were also independent predictors of Hcy. Findings highlight nutrient-environment and gene-environment interactions that could influence the risk of Hcy-related outcomes.]]> Mon 26 Apr 2021 11:34:35 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:29660 CYP2R1, CYP27B1 and CYP24A1) and the Vitamin D receptor gene (VDR). This analysis was conducted in the context of dietary Vitamin D, and background methyl donor related biochemistry, with adjustment for several dietary and lifestyle variables. Percentage methylation at CpG sites was assessed in peripheral blood cells using methylation sensitive and dependent enzymes and qPCR. Standard analytical techniques were used to determine plasma 25(OH)D and homocysteine, and serum folate and B12, with the relationship to methylation status assessed using multi-variable regression analysis. CYP2R1 and VDR methylation were found to be independent predictors of plasma 25(OH)D, when adjusted for Vitamin D intake and other lifestyle variables. CYP24A1 was related to plasma 25(OH)D directly, but not in the context of Vitamin D intake. Methyl-group donor biochemistry was associated with the methylation status of some genes, but did not alter the relationship between methylation and plasma 25(OH)D. Modulation of methylation status of CYP2R1, CYP24A1 and VDR in response to plasma 25(OH)D may be part of feedback loops involved in maintaining Vitamin D homeostasis, and may explain a portion of the variance in plasma 25(OH)D levels in response to intake and sun exposure. Methyl-group donor biochemistry, while a potential independent modulator, did not alter this effect.]]> Mon 26 Apr 2021 10:02:52 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:33435 Fri 30 Aug 2019 12:35:33 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:42277  3R-TS. RCF was measured by chemiluminescent immunoassay and vitamin D2 and D3 by HPLC. Results: RCF and photosynthesized vitamin D3, but not RCF and dietary vitamin D2, exhibit a significant reciprocal association in spring and summer. Three folate genes (C677T-MTHFR, C1420T-SHMT, and 2R > 3R-TS) strengthen this effect in spring, and another (T401C-MTHFD) in summer. Effects are seasonal, and do not occur over the whole year. Conclusions: Findings are consistent with what might be required for the “folate-vitamin D-UV hypothesis of skin pigmentation” model. It suggests genetic influence in provision of one-carbon units by 5,10-methylene-H4folate, may be an important factor in what appears to be a clear seasonal relationship between vitamin D3 and folate status.]]> Fri 11 Aug 2023 09:43:44 AEST ]]>