|Reinhardt, Timothy - Tim|
Submitted to: Journal of Clinical Endocrinology and Metabolism
Publication Type: Peer reviewed journal
Publication Acceptance Date: 11/4/2008
Publication Date: 1/20/2009
Publication URL: http://jcem.endojournals.org/cgi/content/full/94/1/67
Citation: Kremer, R., Campbell, P.P., Reinhardt, T.A., Gilsanz, V. 2009. Vitamin D Status and Its Relationship to Body Fat, Final Height, and Peak Bone Mass in Young Women. Journal of Clinical Endocrinology and Metabolism. 94(1):67-73. Interpretive Summary: Vitamin D is the “sunshine vitamin” and is best known as one key to strong bones. Recent studies have shown that the vitamin D requirement for strong bones is but part of the puzzle, as somewhat higher vitamin D levels is beneficial to fighting disease and lowering the risk of some cancers. This research extends the associated roles of vitamin D to general body metabolism. Low vitamin D levels in young women were associated with increased body fat. These findings support two testable hypotheses that either vitamin D insufficiency is a risk factor for increased body fat or increased body fat is a risk factor for vitamin D insufficiency. These are important human health issues to resolve, but in animal agriculture these data may prove important where body fat in agricultural animals is an important issue for other reasons.
Technical Abstract: Vitamin D insufficiency has now reached epidemic proportion and has been linked to low bone mineral density (BMD), increased risk of fracture and obesity in adults. However, this relationship has not been well characterized in adolescents and young adults. We examined the relationship between serum 25-hydroxyvitamin D (25OHD), anthropometric measures, body fat (BF) and peak bone mass in 90 mature post-pubertal females ages 16-22 of Caucasian and Hispanic background residing in southern California. Serum 25OHD was measured with a radioimmunoassay, total and site specific BF and BMD were measured by DXA and CT and height with the Harpenden stadiometer. Approximately 59% of subjects were vitamin D insufficient (less than or equal to 29 ng/ml), and 41% were sufficient (greater than or equal to 30 ng/ml). Strong negative relationships were present between serum 25OHD and CT measures of visceral and subcutaneous fat and DXA values of BF for the total body, trunk, and extremities. In addition, weight, body mass, and imaging measures of adiposity at all sites were significantly lower in women with normal vitamin D concentrations than women with insufficient vitamin D levels. In contrast, no relationship was observed between circulating 25OHD concentrations and measures of BMD at any site. Unexpectedly, there was a positive correlation between 25OHD levels and height. In conclusion, we found that vitamin D insufficiency is highly prevalent in young mature girls living in sun-exposed areas of the United States, is strongly associated with increased BF and with decreased height but not with changes in peak bone mass.