Effects of vitamin D status on global DNA mthylation

Abstract

Problem: Vitamin D deficiency has been linked to increased risks of hypertension, multiple sclerosis, cardiovascular diseases, and various forms of cancer. Studies have investigated the role of 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) and vitamin D status on epigenetics of specific genes. However, there has not been any investigation on the direct relationship between vitamin D status and global DNA methylation. This study attempted to examine that relationship. Method: Subjects were recruited with flyers around the Boston University Medical (BUMC) campus. Subjects’ blood was drawn at the General Clinical Research Unit (GCRU). Serum was isolated from whole blood by centrifugation. Buffy coat was isolated from whole blood with Accuspin System Histopaque-1077 tubes from Sigma- Aldrich. DNA was isolated from buffy coat with AllPrep DNA/RNA Mini prep from Qiagen. Subject’s serum 25(OH)D concentration was measured with automated IDS-iSYS system, and their percent DNA methylation was measured by high performance liquid chromatography (HPLC). Results: The mean serum 25(OH)D concentration of five subjects was 32.9ng/mL. The mean percent cytosine methylation was 4.7% with standard deviation of 0.2%. One subject was vitamin D deficient, and the remaining four subjects were vitamin D sufficient. The vitamin D deficient subject had a percent cytosine methylation of 4.3%. The mean percent cytosine methylation of vitamin D sufficient subjects was 4.8% with standard deviation of 0.1%. Conclusions: The percent cytosine methylation of the vitamin D deficient subject was lower than the mean percent cytosine methylation of four vitamin D sufficient subjects. This data suggests that there is a possible correlation between vitamin D status and global DNA methylation. However, a larger sample size is needed to make any conclusions for the study.