Zinc status is independently related to the bone mineral density, fracture risk assessment tool result, and bone fracture history: Results from a U.S. nationally representative survey

Abstract

PurposePrevious reports have identified the important role of zinc in bone health. Although the risk of zinc deficiency is still a concern in the U.S., there has never been an in-depth study of the association between zinc status and bone health in a sample representing the country. MethodsWe included 2,895 subjects (aged ≥ 40 years) from National Health and Nutrition Examination Survey (NHANES) 2013–2014 to explore the relationship among three biomarkers of zinc (serum, food, and total intake), the bone mineral density (BMD) of the total spine and femur, the FRAX® scores, and the previous history of bone fractures. ResultsWe showed a one-unit increase in the ln-serum zinc level was associated with an increase in the total spine BMD (ß = 0.068; S.E. = 0.028; P = 0.030) and total femur BMD (ß = 0.061; S.E. = 0.017; P = 0.003), while a one-unit increase in the ln-food zinc intake amount was correlated with an increase in the total femur BMD in the participants (ß = 0.023; S.E. = 0.009; P = 0.021). The ln-total zinc intake amount was correlated with an increase in the total femur BMD in women (ß = 0.016; S.E. = 0.007; P = 0.041). We also found food zinc intake was negatively correlated with the FRAX® score, while increased levels of all three zinc biomarkers were associated with a decreased incidence of previous bone fractures. ConclusionsIn this representative survey of American adults above 40 years old, higher zinc status was associated with higher total spine and femoral BMD, lower FRAX® scores, and lower incidence of previous fractures. If this finding is causal, increased zinc intake remains an important issue for Americans.