Adjusted regression coefficients with 95% confidence intervals (95% CIs) by multiple linear regression analysis for serum parathyroid hormone levels and urinary concentrations of perchlorate, nitrate, and thiocyanate (unadjusted for creatinine) among the United States adults, NHANES 2005–2006.

Model 1: adjusted for age (continuous), race/ethnicity, smoking status, body mass index (continuous), and urinary creatinine (continuous); Model 2: adjusted for variables in Model 1 plus corrected total serum calcium and 25-hydroxyvitamin D levels (both continuous).

Adjusted regression coefficients with 95% confidence intervals (95% CIs) by multiple linear regression analysis for serum parathyroid hormone levels and urinary concentrations of perchlorate, nitrate, and thiocyanate (unadjusted for creatinine) among the United States adults, NHANES 2005–2006.