Associations of the serum 25-hydroxyvitamin D with mortality among patients in osteopenia or osteoporosis.

Purpose: The correlation between serum vitamin D and mortality in patients with osteopenia or osteoporosis remains unclear. Therefore, this study examined the relationship between serum 25-hydroxy vitamin D [(25(OH)D] and mortality in patients with osteopenia or osteoporosis.

Methods And Result: This prospective cohort study included patients with osteopenia or osteoporosis from the National Health and Nutrition Examination Survey from 2001 to 2018. Multivariate Cox regression models examined the correlation between serum 25(OH) D and all-cause mortality, cardiovascular mortality (CVD), and cancer mortality. The cohort included 9282 adult participants with a median follow-up period of 97.01 months, including 1394 all-cause deaths, 413 CVD-related deaths, and 322 cancer deaths. In fully adjusted models, higher serum 25(OH) D levels (≥75.0 nmol/L) were associated with a lower risk of all-cause mortality (hazard ratio 0.54, 95 % confidence interval 0.41 to 0.73) and cardiovascular death (0.47, 0.29 to 0.76), using participants with low 25(OH) D levels (<25 nmol/L) as the reference. In addition, we found an L-shaped non-linear dose-response relationship between serum 25(OH) D and all-cause and cardiovascular mortality, with inflection points of 38.8 nmol/L and 53.6 nmol/L, respectively.

Conclusion: Higher serum 25(OH) D concentrations are strongly associated with a diminished risk of all-cause and CVD mortality in patients with osteopenia or osteoporosis, this association has a threshold effect. More in-depth intervention studies are needed to clarify underlying mechanisms.