Present address: GlaxoSmithKline Pharmaceuticals, King of Prussia, PA J. Yanovski, T. Remaley, N. Sebring, and B. Denkinger are Commissioned Officers in the United States Public Health Service, DHHS.
The prevalence of hypovitaminosis D and secondary hyperparathyroidism in obese Black Americans
Article first published online: 23 MAR 2006
Volume 64, Issue 5, pages 523–529, May 2006
How to Cite
Yanoff, L. B., Parikh, S. J., Spitalnik, A., Denkinger, B., Sebring, N. G., Slaughter, P., McHugh, T., Remaley, A. T. and Yanovski, J. A. (2006), The prevalence of hypovitaminosis D and secondary hyperparathyroidism in obese Black Americans. Clinical Endocrinology, 64: 523–529. doi: 10.1111/j.1365-2265.2006.02502.x
Supported by ZO1 HD-00641 (to JAY) from the National Institute of Child Health and Human Development and by Y2-OD-2067 (to JAY) from the Office of Dietary Supplements, National Institutes of Health, DHHS.
- Issue published online: 23 MAR 2006
- Article first published online: 23 MAR 2006
- (Received 8 September 2005; returned for revision 4 October 2005; finally revised 3 December 2005; accepted 30 December 2005)
Context Both obesity (body mass index, BMI ≥ 30 kg/m2) and Black race are associated with a higher risk of vitamin D deficiency and secondary hyperparathyroidism. We hypothesized the risk of hypovitaminosis D would therefore be extraordinarily high in obese Black adults.
Objective To study the effects of race and adiposity on 25-hydroxyvitamin D [25(OH)D] and parathyroid hormone (iPTH).
Design, Setting and Participants Cross-sectional study of 379 Black and White adults from the Washington D.C. area. BMI ranged from 19·9 to 58·2 kg/m2.
Main Outcome Measures Prevalence of hypovitaminosis D [25(OH)D < 37·5 nmol/l] and secondary hyperparathyroidism [25(OH)D < 37·5 nmol/l with iPTH > 4·2 pmol/l].
Results Obese Black subjects had lower mean 25(OH)D, 40·3 (SD, 20·3) nmol/l, compared with obese Whites, 64·5 (29·7), P < 0·001, nonobese Blacks, 53·3 (26·0), P = 0·0025 and nonobese Whites, 78·0 (33·5), P < 0·001. The prevalence of hypovitaminosis D increased with increasing BMI, and was greater (P < 0·001) in Blacks than Whites within all BMI categories examined. Among subjects with BMI ≥ 35 kg/m2, 59% of Blacks vs 18% of Whites had hypovitaminosis D (odds ratio 6·5, 95% confidence interval 3·0–14·2). iPTH was negatively correlated with 25(OH)D (r = –0·31, P < 0·0001), suggesting those with hypovitaminosis D had clinically important vitamin D deficiency with secondary hyperparathyroidism. For secondary hyperparathyroidism 35·2% of Blacks met the criteria, compared to 9·7% of Whites (OR 3·6, CI 1·5–98·8).
Conclusions Obese Black Americans are at particularly high risk for vitamin D deficiency and secondary hyperparathyroidism. Physicians should consider routinely supplementing such patients with vitamin D or screening them for hypovitaminosis D.