MedicalResearch.com Interview with:
Haidong Zhu, MD, PhD
Associate Professor of Pediatrics
Georgia Prevention Institute
Medical College of Georgia
MedicalResearch.com: What is the background for this study? What are the main findings?
Dr. Zhu: Vitamin D plays an important role in a wide range of body functions beyond bone health. Vitamin D deficiency is associated with increased risk of cancer and cardiovascular disease. Vitamin D deficiency is common among darker skin individuals, particularly African-Americans, which could contribute to health disparity. We want to understand underlying molecular mechanism (i.e. global DNA methylation) for how vitamin D deficiency causes cancer, cardiovascular disease and impaired immune function. DNA methylation, a chemical modification to our genome, is one of the ways that our body adapts to the environment. Low rate of global DNA methylation is a common event in cancer, which may lead to disturbances in the genome, make the genome more vulnerable to environmental damage and increase disease risk.
Our study shows that majority of black teens are vitamin D deficient and have a lower rate of global DNA methylation than white teens. We further demonstrate that vitamin D3 supplementation for 16 weeks increases global DNA methylation in black teens and young adults. Our study provides an important piece of evidence that vitamin D plays a role in epigenetic regulation in humans, which could be an underlying mechanism for vitamin D-deficiency related disease risk and health disparity.
MedicalResearch.com: What should clinicians and patients take away from your report?
Dr. Zhu: Our report provides a new layer of evidence that vitamin D helps regulate many important body functions. Although much work remains, vitamin D deficiency or insufficiency may increase cancer risk or disease risk. There are several ongoing phase I trials to determine whether vitamin D supplements can prevent the development of a variety of cancers. Clinicians and patients should stay tuned for new developments. In the meantime, increasing intake from vitamin D rich food (i.e. fatty fish, like tuna and salmon, cheese, eggs, dairy products fortified with vitamin D) and increasing outdoor activity may help prevent vitamin D deficiency. Vitamin D can also be obtained through dietary supplements. The institute of Medicine (IOM) of the National Academies recommends daily intake of 600 IU vitamin D for those between 1 and 70 years of age, 800 IU for those 71 years or older and 400 IU for infants.
MedicalResearch.com: What recommendations do you have for future research as a result of this study?
Dr. Zhu: Our study provides the first evidence that vitamin D regulates global DNA methylation in humans. Future research should identify specific vitamin D target sites in the genome and pathways that regulate body function. The effect of vitamin D on other epigenetic machineries (i.e. histone modification and microRNA) should also be examined in humans.
MedicalResearch.com: Thank you for your contribution to the MedicalResearch.com community.
Race/Ethnicity-Specific Association of Vitamin D and Global DNA Methylation: Cross-Sectional and Interventional Findings, Haidong Zhu, Jigar Bhagatwala, Ying Huang, Norman K. Pollock, Samip Parikh, Anas Raed, Bernard Gutin, Gregory A. Harshfield, Yanbin Dong
PLOS ONE, doi: 10.1371/journal.pone.0152849, published 6 April 2016
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