Dietary Protein and Vitamin D Intake and Risk of Falls: A Secondary Analysis of Postmenopausal Women from the Study of Osteoporotic Fractures

More than 90% of hip fractures in older Americans result from a fall. Inadequate intake of dietary protein and vitamin D are common in older adults, and diets in low these could contribute to loss of muscle mass and strength or coordination, in turn increasing the risk of falling. The objective of the study was to evaluate the relationship between protein and vitamin D intake with the occurrence of falls in older women in the Study of Osteoporotic Fracture, a prospective cohort of more than 4000 postmenopausal women participating from January 1997 to September 1998. Incident falls were ascertained for one year. Protein and vitamin D intake was assessed by a food frequency questionnaire; associations with a reported fall were estimated with logistic regression, adjusted for fall-related covariates and energy. Protein and vitamin D were modeled separately because of high correlation (rho = 0.55, P < 0.001). A total of 1429 women reported a fall within one year. In separate, unadjusted models dietary protein (per 1 g/kg increase) and vitamin D (per 100 International Unit (IU) increase) significantly increased the odds ratio (OR) of falling (OR 1.35 95% CI 1.15–1.59, OR 1.11 95% CI 1.03–1.19, respectively). Once fall-related covariates were added to each model, dietary protein and vitamin D were noncontributory to falls. While we could find no direct association between vitamin D and protein intake and fall prevention, adequate intake of these two nutrients are critical for musculoskeletal health in older adults.