Evaluation of Vitamin D Storage in Adipose Tissue

Evaluation of Vitamin D Storage in Adipose Tissue

Severely obese individuals commonly have very low vitamin D levels. This can be a serious problem because low vitamin D levels are associated with bone disease, including broken bones and other medical conditions such as diabetes, high blood pressure, and cancer which already affect the obese population. Weight loss, or bariatric surgery, is also associated with low vitamin D levels and patients who have low levels even before the operation may be at increased risk.

Different factors have been suggested to explain the low vitamin D levels in obese people, including that they do not eat enough foods or take enough vitamins that contain vitamin D, and that they do not get enough sunlight (since vitamin D can be made in the skin when it is exposed to enough UV light). Another explanation is that vitamin D gets stored in the excess fat tissue of obese individuals, and is not available to the rest of the body. Two small studies have found measurable amounts if vitamin D in samples of fat tissue. We propose a pilot study to investigate whether there are different concentrations of vitamin D in the fat tissue in morbidly obese and normal weight subjects. We will recruit morbidly obese subjects who are about to have bariatric surgery, and normal weight subjects who are about to have other elective abdominal operations. We will measure vitamin D levels in blood, and measure the concentration of vitamin D in the fat samples from both groups of subjects.

The results obtained in this study may help us understand the method by which vitamin D deficiency occurs in the morbidly obese population.

We will also measure changes in bone density (by DXA) and bone microarchitecture (by high resolution peripheral QCT) before and after bariatric surgery to investigate whether bone density declines after bariatric surgery, which may be a healthy adaptive response to weight loss, or reflect a damaging underlying condition. If bone density declines but microarchitecture does not change after surgery, that would support an adaptive mechanism.

Specialty Area(s)

Trial Location

180 Fort Washington Ave.
Harkness Pavilion 9-910
New York, NY 10032
United States