8-hydroxy-2--deoxyguanosine and Vitamin-D-Deficiency

The concurrent impact of repeated low-level summer sunlight exposures on vitamin D production and cutaneous DNA damage, potentially leading to mutagenesis and skin cancer, is unknown.. This is an experimental study (i) to determine the dual impact of repeated low-level sunlight exposures on vitamin D status and DNA damage/repair (via both skin and urinary biomarkers) in light-skinned adults; and (ii) to compare outcomes following the same exposures in brown-skinned adults.. Ten white (phototype II) and six South Asian volunteers (phototype V), aged 23-59 years, received 6 weeks' simulated summer sunlight exposures (95% ultraviolet A/5% ultraviolet B, 1·3 standard erythemal doses three times weekly) wearing summer clothing exposing ~35% body surface area. Assessments made were circulating 25-hydroxyvitamin D [25(OH)D], immunohistochemistry for cyclobutane pyrimidine dimer (CPD)-positive nuclei and urinary biomarkers of direct and oxidative (8-oxo-deoxyguanosine) DNA damage.. Serum 25(OH)D rose from mean 36·5 ± 13·0 to 54·3 ± 10·5 nmol L. Low-dose summer sunlight exposures confer vitamin D sufficiency in light-skinned people concurrently with low-level, nonaccumulating DNA damage. The same exposures produce minimal DNA damage but less vitamin D in brown-skinned people. This informs tailoring of sun-exposure policies.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Adolescent; Adult; Asia, Southeastern; Biomarkers; Deoxyguanosine; Diet; DNA Damage; DNA Repair; Environmental Exposure; Female; Humans; Male; Middle Aged; Pyrimidine Dimers; Seasons; Skin; Skin Neoplasms; Skin Pigmentation; Sunlight; Vitamin D; Vitamin D Deficiency; Young Adult