Time trend 2000-2013 of vitamin D status in older people who sustain hip fractures: steps forward or steps back? A retrospective study of 1599 patients.

Background: Substantial proportions of hip-fracture patients have very low serum levels of 25-hydroxyvitamin D, which can negatively affect rehabilitation. However, it is not known whether changes in vitamin D deficiency have occurred over the last years in the patients who sustain hip fractures.

Aim: To assess time trend 2000-2013 of calcifediol serum levels in the hip-fracture patients admitted to our rehabilitation division.

Design: Retrospective observational study.

Setting: A rehabilitation hospital division.

Population: A number of 1599 inpatients with a hip fracture admitted between January 1, 2000 and December 31, 2013 to our rehabilitation division.

Methods: A blood sample was collected in the morning following an overnight fasting 14.4±4.4 (mean±SD) days after surgery. We assessed 25-hydroxyvitamin D levels by an immunoenzymatic assay.

Results: Calcifediol levels increased till 2006-2007 and decreased afterward. In 2006-2007, the median 25-hydroxyvitamin D level (13.1 ng/mL, interquartile range 7.9-25ng/mL) was significantly higher (P<0.001) than the one found in both the periods 2000-2001 (5.4 ng/mL, interquartile range 3.5-9 ng/mL), and 2012-2013 (7ng/mL, interquartile range 5-14 ng/mL). In the last two-year period of observation (2012-2013), 25-hydroxyvitamin D levels were slightly higher (P<0.001) than in the first one (2000-2001). The association between periods of observation and 25-hydroxyvitamin D levels persisted after adjustment for age, BMI, and sex (P<0.001).

Conclusions: A significant increase in calcifediol concentrations was seen till 2006-2007, but a significant decrease was observed afterward. Finally, calcifediol levels were only slightly higher in the last two years of observation than in the first two years and severe vitamin D deficiency was common during the whole 14-year study period.

Clinical Rehabilitation Impact: Heightened awareness is needed to prevent and treat vitamin D deficiency in hip-fracture patients.