LAUSR

Previous studies have reported that serum klotho and vitamin B12 levels are valuable aging-related markers. However, studies supporting the association between serum klotho and vitamin B12 levels are lacking. We investigated the association between serum klotho and vitamin B12 concentrations in adults in the United States. The analytic study sample was 2065 aged 40 to 79 who participated in the 2011 to 2014 National Health and Nutrition Examination Survey (NHANES). Serum klotho and vitamin B12 collected from adults who consented to the use of their samples in the future. The participants were divided into 2 groups based on estimated glomerular filtration rate (eGFR) levels (high: ≥90 mL/min/1.73 m2 or low: <90 mL/min/1.73 m2). Of the 2065 participants, the log-transformed klotho concentration was significantly correlated with log-transformed vitamin B12 in the high eGFR group, but not in the low eGFR group. After adjusting for all potential covariates, there was a significant association between klotho and vitamin B12 concentrations in the high eGFR groups (beta = 0.100, SE = 0.040). In contrast, there was no significant relationship between klotho and vitamin B12 concentrations in the low eGFR group (beta = 0.012, SE = 0.019). Serum klotho concentration was significantly associated with vitamin B12 increases in US adults with high kidney function. Vitamin B12 concentration may be an important marker of klotho concentration in older adults.