Objectives: To determine the associations of selenium and zinc on health.
Methods: A cross-sectional study; adults (mean age 65 years), Freemasons or spouses resident of the North Island of New Zealand; measures of cognition, the Timed Up and Go (TUG) test, and hair and toenail zinc and selenium levels. Multivariable logistic regression was used to determine significant associations.
Results: Univariate analyses showed a significant association of decreased likelihood of impaired performance (> 9.5 seconds) on the TUG test with increasing quartiles of nail selenium (odds ratio 0.73; 95% confidence interval 0.61–0.87). The association persisted in a multivariate model. No associations were seen for any of the other measures.
Conclusion: Low nail selenium levels were associated with impaired physical function, as a result of chance from multiplicity problems, bias or a true adverse effect of selenium deficiency. Prospective studies are necessary to more reliably discern temporal associations of micronutrients on health.