Document Type



Doctor of Philosophy (PhD)


Dietetics and Nutrition

First Advisor's Name

Fatma Huffman, PhD, RD

First Advisor's Committee Title

Committee chair

Second Advisor's Name

Adriana Campa, PhD, RD

Second Advisor's Committee Title

Committee member

Third Advisor's Name

Juan Liuzzi, PhD

Third Advisor's Committee Title

Committee member

Fourth Advisor's Name

Tan Li, PhD

Fourth Advisor's Committee Title

Committee member


dietetics; nutrition

Date of Defense



The aim of the present study was to assess the effect of 4000 IU and 6000 IU of daily vitamin D3 supplementation for 3 months and 6 months on 8-hydroxy-2`-deoxyguanosine (8-OHdG) and glycated albumin (GA%) among a group of individuals with T2D and hypovitaminosis D. Furthermore, this study investigated the association between dietary inflammatory index (DII), C-reactive protein (CRP), 8-OHdG, hemoglobin A1C (HbA1c), GA% and insulin. Ninety participants were recruited by community outreach and were screened. Sixty-eight participants met the inclusion criteria were enrolled and completed the study. DII for each individuals was calculated based on the values obtained from a validated food frequency questionnaire. Measurements of variables were conducted at baseline, after 3 months and after 6 months of supplementation. Serum CRP, 8-OHdg, GA%, HbA1c and insulin were measured by enzymatic immunoassay methods. Mixed model was used to compare treatment groups. Covariates in the adjusted model included age, gender, body mass index (BMI), insulin, HbA1c, years with type 2 diabetes, perceived stress, physical activity, and sun exposure. Mean age was 54.94± 7.93 years.A multivariable linear regression model adjusted for age, gender, waist circumference, and fasting plasma glucose was used to test for the linear trend between DII and CRP, 8-OHdG, GA% and insulin.The unadjusted model showed no significant associations between quartiles of DII, CRP, HbA1c and GA%. A significant inverse association was observed between the fourth DII quartile and insulin level (p=0.030). There was a significant association between SBP and DII in Q4 (p=0.029).The unadjusted mean ± SD for 8-OHdG levels at baseline, after 3 and 6 months were 8068.94 ± 2158.13 pg/mL, 9462.22 ± 2403.89 pg/mL, and 7412.69 ± 2031.68 pg/mL, respectively. The unadjusted mixed model showed no difference between the 4000 and 6000 IU groups regarding the oxidative stress and GA%. Interactions between time and treatment were not significant. The model showed a statistically significant difference in 8-OHdG level between baseline and 3 months (PP=0.015), and from 3 months to 6 months (P=0.039), but not from baseline to 6 months (P= 0.488). The results of the present study showed daily oral supplementation with higher doses of vitamin D for 6 months may have beneficial effects on oxidative stress and glycemic status among a group of individuals with type 2 diabetes and vitamin D deficiency/insufficiency. Furthermore, pro-inflammatory dietary patterns may be associated with increased risk of hyperinsulinemia and hypertension among individuals with T2D and hypovitaminosis D.



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Nutrition Commons



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