8-Hydroxy-2-deoxyguanosine: A Marker for Oxidative Stress affected by Varying Levels of Vitamin D

The discovery of vitamin D's involvement in genetic, cardiovascular and inflammatory disorders has inspired interest in furthering the understanding of its atypical functions. Vitamin D's ability to attenuate oxidative damage to DNA is the premise behind this study. The impact of 25-hydroxyvitamin D (25(OH)D) on oxidative stress levels was retrospectively analyzed in a case control study, that included data from 502 clinical laboratory reports. The Institutional Review Board granted the study an exempt status. The results from participants with optimal 25(OH)D levels (control group) and participants with suboptimal 25(OH)D levels (case group) were studied to determine an association between serum 25(OH)D and urinary 8-hydroxy-2-deoxyguanosine (8(OH)DG) levels, a biomarker for oxidative stress levels. Results revealed that 8(OH)DG levels were higher in individuals aged 18 to 50 when compared to individuals younger than 18 years (p=0.001) and over 50 years (p=0.009). 25(OH)D levels increased with age, with participants over 50 years exhibiting the greatest serum levels (p≤0.001). Females had higher levels of 25(OH)D at all age groups, whereas 8(OH)DG levels were consistent between genders. Comparisons between 25(OH)D and 8(OH)DG levels revealed that the control group had the highest urinary values of 8(OH)DG, although the results were not significant. Subsequently 8(OH)DG levels decreased with declining 25(OH)D levels suggesting that vitamin D deficient individuals had lower levels of oxidative stress. It can be concluded that there are many factors influencing one's serum 25(OH)D status and 8(OH)DG levels, these include dietary intake, age, UVB exposure, obesity, ethnicity and sunscreen use, necessitating an integrative approach in analyzing the relationship between these two values. The results suggest that further studies need to be conducted in order to determine whether serum 25(OH)D levels have a direct impact on urinary 8(OH)DG levels.