Inverted U-shaped relationship between serum vitamin B12 and α-Klotho levels in US adults: a cross-sectional study.

Background: Serum vitamin B12 and α-Klotho are important markers associated with aging. Limited studies have been conducted on the relationship between vitamin B12 and α-Klotho.

Objectives: This study investigated the relationship between circulating α-Klotho and vitamin B12.