https://nova.newcastle.edu.au/vital/access/ /manager/Index en-au 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: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:37800 (DHCR7/NADSYN1, GC, CYP2R1, CYP11A1, CYP27A1, CYP24A1, VDR, RXRα and RXRγ) was collated from 60 sample sets (2633 subjects) with European, East Asian and Sub-Saharan African origin via the NCBI 1000 Genomes Browser and ALFRED (Allele Frequency Database), with the aim to examine for patterns in the distribution of vitamin D-associated variants across these geographic areas. Results: The frequency of all examined genetic variants differed between populations of European, East Asian and Sub-Saharan African ancestry. Changes in the distribution of variants in CYP2R1, CYP11A1, CYP24A1, RXRα and RXRγ genes between these populations are novel findings which have not been previously reported. The distribution of several variants reflected changes in the UVB environment of the population's ancestry. However, multiple variants displayed population-specific patterns in frequency that appears not to relate to UVB changes. Conclusions: The reported population differences in vitamin D-related variants provides insight into the extent by which activity of the vitamin D system can differ between cohorts due to genetic variance, with potential consequences for future dietary recommendations and disease outcomes.]]> Mon 26 Apr 2021 10:45:36 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 ]]>