The literature describing vitamin D content of fat tissue is extremely limited. We conducted a pilot study that measured the concentrations of vitamin D3 in the fat tissue and serum of obese adults. These measurements were performed using a new liquid chromatography mass spectrometry (LC/MS) method. The objectives of this study were: to measure and report the vitamin D3 concentration in serum and subcutaneous fat samples from obese individuals and to examine the association of vitamin D3 in fat with vitamin D3 in serum. This cross-sectional study was conducted in 17 obese men and women who were scheduled to undergo gastric bypass surgery. The mean vitamin D3 concentration in subjects’ subcutaneous fat tissue samples was 102.8 ± 42.0 nmol/kg. The mean vitamin D3 concentration in serum was 7.78 ± 3.99 nmol/l. Vitamin D3 concentrations of fat tissue and serum were positively correlated (r = 0.68, P = 0.003). Consistent with previous findings in obese subjects, subjects in this study had suboptimal vitamin D status as demonstrated by a mean 25-hydroxyvitamin D concentration of 43.3 ± 15.4 nmol/l. In conclusion, fat tissue vitamin D3 can be measured by LC/MS and is detectable in obese subjects with suboptimal vitamin D status. Compatible with the long-standing concept that fat tissue is a storage site for vitamin D, fat tissue and serum vitamin D3 concentrations were positively correlated.
KeywordsVitamin D3 Fat tissue Serum 25-Hydroxyvitamin D Obesity
This research was supported by NIH grant number K23 AR47869 and by contract No. 58-1950-7-707 with the Jean Mayer U.S. Department of Agriculture Human Nutrition Research Center on Aging at Tufts University. This article does not necessarily reflect the views or policies of the U.S. Department of Agriculture, nor does mention of trade names, commercial products, or organizations imply endorsement by the U.S. government.
- 9.M. Blum, G. Dolnikowski, B. Dawson-Hughes, Body size and serum hydroxyvitamin D response to oral supplements in healthy older adults. J Am Coll Nutr. (2007) (in press)Google Scholar
- 11.Standing Committee on the Scientific Evaluation of Dietary Reference Intakes F. a. N. B. I. o. M, Dietary Reference Intakes for Calcium, Phosphorus, Magnesium, Vitamin D and Fluoride. (National Academy Press, Washington, D.C, 1997)Google Scholar