Jones, PatriceLucock, MarkScarlett, Christopher J.Veysey, MartinBeckett, Emma2026-01-012026-01-011661-7827Bibtex:jones2020environmentalcohortORCID:/0000-0002-8652-0036/work/188019767https://hdl.handle.net/1885/733800184Ultraviolet radiation (UVR) is a ubiquitous exposure which may contribute to decreased folate levels. Skin pigmentation mediates the biological effect of UVR exposure, but its relationship to folate levels is unexamined. Interactions may exist between UVR and pigmentation genes in determining folate status, which may, in turn, impact homocysteine levels, a potential risk factor for multiple chronic diseases. Therefore, independent and interactive influences of environmental UVR and genetic variants related to skin pigmentation (MC1R-rs1805007, IRF4-rs12203592 and HERC2- rs12913832) on folate (red blood cell (RBC) and serum) and homocysteine levels were examined in an elderly Australian cohort (n = 599). Genotypes were assessed by RT/RFLP-PCR, and UVR exposures were assessed as the accumulated erythemal dose rate accumulated over 4 months (4M- EDR). Multivariate analysis found significant negative associations between 4M-EDR and RBC folate (p < 0.001, β = −0.19), serum folate (p = 0.045, β = −0.08) and homocysteine levels (p < 0.001, β = −0.28). Significant associations between MC1R-rs1805007 and serum folate levels (p = 0.020), and IRF4-rs12203592 and homocysteine levels (p = 0.026) occurred but did not remain significant following corrections with confounders. No interactions between 4M-EDR and pigmentation variants in predicting folate/homocysteine levels were found. UVR levels and skin pigmentation-related variants are potential determinants of folate and homocysteine status, although, associations are mixed and complex, with further studies warranted.This research conducted as part of the Retirement Health and Lifestyle Study, with initial and ongoing funding provided by the Australian Research Council (G0188386), Central Coast Local Health District Public Health Unit (G0190658/G1700259), Uniting Care Ageing NSW/ACT (G0189230), Urbis Pty Ltd. (G0189232), Valhalla Village Pty Ltd. (G1000936), and Hunter Valley Research Foundation.14en© 2020 The Author(s)folateskin pigmentationultraviolet radiationnutrigeneticsgene-nutrient-environment interactions2020-02-2810.3390/ijerph1705154585080962665