Date of Award

January 2016

Degree Type


Degree Name

Doctor of Philosophy (PhD)


Nutrition Science

First Advisor

Dorothy Teegarden

Committee Member 1

Kimberly K Buhman

Committee Member 2

Shawn S Donkin

Committee Member 3

Kee-Hong Kim

Committee Member 4

Shihuan Kuang


Obesity is a major public health concern, both in the United States and worldwide. Therefore, identification of measures by which obesity may be prevented and reversed is of high priority. Epidemiological studies consistently demonstrate an inverse relationship between serum 25(OH)D levels, an indicator of vitamin D status, and measures of adiposity. These data suggest that vitamin D may play a role in the prevention of excessive adiposity. However, whether vitamin D impacts lipid storage and metabolism in terminally differentiated adipocytes is not yet known. The purpose of this work was to determine the impact of 1,25-dihydroxyvitamin D (1,25(OH)2D), the bioactive vitamin D metabolite, on triacylglycerol accumulation and lipid and glucose metabolism in differentiated adipocytes. To study this, 3T3-L1 adipocytes were differentiated for 9 days, followed by stimulation with 1,25(OH)2D (10 nM) or vehicle for 1-7 days. Results indicate that 1,25(OH)2D stimulates a 21% reduction in TAG accumulation in differentiated 3T3-L1 adipocytes after 4 days (P=0.01). This occurs despite a significant increase in fatty acid uptake (P<0.01), assessed using BODIPY FL C16, and with concomitant stimulation of PKA-dependent