Summary measure of dietary musculoskeletal nutrient (calcium, vitamin D, magnesium, and phosphorus) intakes is associated with lower-extremity physical performance in homebound elderly men and women

Nutritional intake has been overlooked as a possible contributing factor to lower-extremity physical performance, especially in homebound elderly persons. Our objectives were to examine the association of a summary measure of calcium, vitamin D, magnesium, and phosphorus intakes with 1) the inability to perform lower-extremity physical performance tests and 2) declining levels of summary lower-extremity physical performance. Baseline data from the Nutrition and Function Study were used to calculate a summary musculoskeletal nutrient (SMN) score as a measure of nutrient intake (factor analysis) and to examine the association of SMN intake with physical performance (multivariable regression models) among recipients of home-delivered meals who completed an in-home assessment (anthropometric measures and performance-based physical tests) and three 24-h dietary recalls. Among the 321 participants, elderly age, black race, body mass index (in kg/m2) > or = 35, arthritis, frequent fear of falling, and lowest SMN intake were independently associated with being unable to perform functional tests. The lowest SMN intake and the highest BMI were both significantly associated with increasingly worse levels of lower-extremity physical performance, after adjustment for health and demographic characteristics. Considering the importance of identifying short- and long-term outcomes that help elderly persons maintain adequate nutritional status and remain functionally independent at home, the results of this study suggest the need to identify intervention strategies that target the improvement of dietary intake and physical performance. Further investigation is indicated to identify the manner in which nutritional status contributes to the preservation or deterioration of physical performance in homebound elderly persons.