Association Between Dietary Selenium Intake and Bone Mineral Density: A Cross-sectional Study Using National Health and Nutrition Examination Survey

Assessments of whether dietary selenium intake is related to bone health are scarce, with few relevant studies limited by its small sample. The aim of present study was to investigated the association between dietary selenium intake and bone mineral density (BMD) levels in different sites, including total femur, femur neck, trochanter and intertrochanter in femur and lumbar spine in the National Health and Nutrition Examination Survey (NHANES) database. Generalized linear models for the association between dietary selenium intake and BMD and generalized additive model for the dose-response relationship were used. A total of 21939 participants were included, and the mean age was 40.68 ± 22.42 years, and 51.28% were male. In multivariable adjustment model, participants had highest quintiles of dietary selenium intake (Q5) were associated with increased BMD levels in total femur ( β =0.014, 95CI%: 0.008, 0.020, P ＜0.001), femur neck ( β =0.010, 95CI%: 0.004, 0.016, P =0.001), trochanter ( β =0.011, 95CI%: 0.005, 0.017, P ＜0.001), intertrochanter ( β =0.017, 95CI%: 0.010, 0.025, P ＜0.001) and lumbar spine ( β =0.013, 95CI%: 0.005, 0.020, P ＜0.001) compared with those in quintiles 1 (Q1). The dose-response relationship showed the inverted U-shape relationship between dietary selenium relationship and BMD levels ( P for non-linearity ＜0.05). Participants tended to have increased levels of BMD as the dietary selenium intake increased when dietary selenium was below the turning point, and then a negative relation was observed when dietary was higher than the turning point. Our study indicated that higher dietary selenium intake was associated with increased BMD levels in total femur, femur neck, trochanter, intertrochanter, and lumbar spine, and these relationships were nonlinear. Future high-quality, prospective longitudinal studies are needed to confirm these findings.