Physical inactivity and vitamin D deficiency in hospitalized elderlies.

Serum levels of 25(OH)D, which is known to correlate with systemic nutritional status, is used as an indicator of vitamin D sufficiency in the body. We studied the 25(OH)D status and its background factors including activity of daily living (ADL) in the elderlies hospitalized at the regional core hospital. We also examined whether or not vitamin D deficiency affects ADL among them. This study included newly hospitalized patients aged 65 years or over at Ohchi hospital April to August in 2015. At the time of admission, serum 25(OH)D concentration was measured, and ADL, instrumental ADL (IADL), cognitive function, blood test, nursing care certification were investigated as background factors. Among 209 patients, 25(OH)D was sufficient (> 30 ng/mL) only 14 cases (7%), insufficient (20-30 ng/mL) in 43 cases (20%), and deficient (< 20 ng/mL) in 152 cases (73%). Multivariate analysis showed that low ADL (OR 0.99, 95% CI 0.97-0.99) and low IADL (OR 0.88, 95% CI 0.78-0.99) were independent predictors of 25(OH)D deficiency in two models incorporating ADL and IADL, respectively. Furthermore, low 25(OH)D level was significantly associated with low ADL (OR 0.95, 95% CI 0.91-0.99) and low IADL (OR 0.93, 95% CI 0.88-0.97) scores, suggesting that vitamin D deficiency may affect physical activities. Most hospitalized elderly patients in Japan were deficient for vitamin D. In addition, physical inactivity is strongly associated with vitamin D deficiency.