Biostatistics Student Discovers Link Between Vitamin D and Cholesterol
Vitamin D has long been associated with good health. It is well documented that patients deficient in Vitamin D in both diet and sun exposure are at risk for osteomalacia in adults or rickets in children. Rickets is characterized by deformed, long bones that bow under a childs weight when they start to walk while ostiomalacia is associated with higher instances of broken bones and musculoskeletal pain.
New research has also started to associate vitamin D levels with development of cardiovascular diseases. Deficiency in vitamin D has been closely associated with increased risk of major adverse cardiovascular events including stroke and heart attacks. These findings have also led to an increase in prescribing vitamin D supplements as a cheap alternative to other supplements that benefit heart health.
A less understood component of this area of research involves the role of foods that contain both vitamin D and cholesterol. These foods, including eggs, pork, and butter are some of the most debated food items due to our constantly shifting understanding of cholesterol, vitamin D, and heart disease.
Eunice Mogusu, a graduate student in Biostatistics working with Dr. Shimin Zheng, an Assistant Professor of Biostatistics and member of the CIIDI, Dr. Sreenivas Veeranki, at the University of Texas, and David Kioko and Dr. Megan Quinn, both at ETSU has identified an association between a vitamin D deficiency and total cholesterol levels, triglycerides, and LDL levels (often referred to as the bad cholesterol). Mogusu conducted a logistic regression analysis using the CDC National Health and Nutrition Examination Survey (NHANES) from 2001-2006. She and her team controlled for physical activity, which can act as a proxy measure for sunlight exposure. Mogusu was also been able to identify risk factors for vitamin D deficiency. Females have a significantly higher rate of vitamin D deficiency as do survey respondents between the age of 19 and 50. It is hypothesized that this could be related to multiple factors including liver function, kidney function, or lifestyle factors including diet, obesity, and sedentary behaviors. NHANES is a national probability survey conducted bi-annually by the National Center for Health Statistics. It exists primarily to estimate the prevalence of chronic health conditions and risk factors among the US population.
Mogusu will present on this subject at this years American Public Health Association (APHA) Annual Meeting in Chicago this October. Presenting at APHA while still an MPH student is an honor that few students will have the opportunity to experience. Mogusu says that the subject matter of this presentation was slightly out of the ordinary for her, but very interesting because vitamin D and its relationship with cholesterol is a relatively new field with limited literature.
"Obesity continues to be a major health issue in America and especially in Tennessee and the Appalachian region and is associated with various chronic diseases that are a leading cause of mortality in the U.S such as diabetes, high blood pressure, heart conditions and others. This led me to further explore from existing literature whether there exists other variables that might have been overlooked with regards to obesity and nutrition. Although the question about Vitamin D levels was dropped from the questionnaire by NHANES after 2006, thus limiting the number of years of data available to us, using the data and with the help of Dr. Zheng, we delved deeper to assess and understand the association between the levels of Vitamin D in the body and the levels of cholesterol LDL and HDL.
Mogusus primary research interest is maternal and child health, specifically looking
at statistical analyses of premature births and low birth weight. She would like the
opportunity to continue to study the effects of vitamin D on cholesterol once another
source of data is made available.
I believe that nutrition and healthy eating habits are a good starting point with reference to preventing obesity among populations, a major goal of public health. By ensuring that we are getting enough vitamin D, then we shall keep the
levels of bad cholesterol low and hence avoid other chronic illnesses" said Mogusu.