Association between dietary vitamin B6 intake and total bone mineral density in adolescents: a cross-sectional study of NHANES 2011–2018

Abstract

Adolescence is a critical period for peak bone mass acquisition, which plays a pivotal role in lifelong skeletal health. However, the association between dietary vitamin B6 intake and bone mineral density (BMD) during this developmental stage remains unclear. This study aimed to investigate the association between dietary vitamin B6 intake and total BMD among U.S. adolescents. This cross-sectional study included 2,444 adolescents aged 12–19 years from the National Health and Nutrition Examination Survey (NHANES) 2011–2018. Dietary vitamin B6 intake was estimated using the average of two 24-hour dietary recalls. Total BMD (g/cm²) was measured by dual-energy X-ray absorptiometry (DXA). Survey-weighted generalized linear models with a Gaussian distribution and identity link were used to evaluate the association between dietary vitamin B6 intake and total BMD after adjustment for demographic characteristics, socioeconomic status, lifestyle factors, anthropometric measures, clinical characteristics, laboratory biomarkers, and dietary nutrients. A sensitivity analysis further adjusted for overall dietary quality using the Healthy Eating Index-2015 (HEI-2015) score and total energy intake. Dietary vitamin B6 intake showed a modest positive association with total BMD when modeled as a continuous variable. In the multivariable-adjusted model (Model 3), each 1 mg/day increase in dietary vitamin B6 intake was associated with a 0.0070 g/cm² higher total BMD (β = 0.0070; 95% CI: 0.0016–0.0123; P = 0.015). After further adjustment for the HEI-2015 score and total energy intake in Model 4, the continuous association remained statistically significant, although the effect estimate was modestly attenuated (β = 0.0065; 95% CI: 0.0003–0.0127; P = 0.046). However, the highest-versus-lowest-quartile comparison and the linear trend across quartiles were not statistically significant in Model 4. Higher dietary vitamin B6 intake was modestly associated with higher total BMD among U.S. adolescents when modeled as a continuous variable, although the categorical findings were not statistically significant after additional dietary adjustment. Given the cross-sectional design and substantial potential for residual confounding, these findings should be interpreted cautiously and should not be regarded as evidence of a causal relationship.

The authors' abstract, as published at the source. BMC Nutrition, 2026 · DOI ↗