1. Department of Epidemiology; University of Alabama at Birmingham; Birmingham AL USA
2. National Center for Health Statistics; Centers for Disease Control and Prevention; Hyattsville MD USA
3. Division of Clinical Immunology & Rheumatology; University of Alabama at Birmingham; Birmingham AL USA
4. National Osteoporosis Foundation; Washington DC USA
5. Jean Mayer USDA Human Nutrition Research Center on Aging; Tufts University; Boston MA USA