Lewis JR, Brennan-Speranza TC, Levinger I, et al. - In this post hoc analysis of a randomized double-blind, placebo-controlled trial, 1,368 older community-dwelling women recruited in the Calcium Intake Fracture Outcome Study trial (1998–2003) were administered 1.2 g/d of elemental calcium (in the form of calcium carbonate) or placebo in order to investigate whether 1 year of calcium supplementation influenced circulating total osteocalcin (TOC), undercarboxylated osteocalcin (ucOC) or glycated hemoglobin (HbA1c). Subsequent to 1 year of calcium supplementation, TOC and ucOC levels were 17% and 22% lower, in contrast, to the placebo. Carboxylated osteocalcin/ucOC was 6% lower following calcium supplementation. Notwithstanding this, no variations in HbA1c were seen. BMI, whole-body lean or fat mass was not influenced by calcium supplementation. In exploratory analyses, total calcium (dietary and supplemental) was inversely associated with TOC and ucOC, suggesting calcium consumption is a significant dietary determinant of osteocalcin levels. Thus, with no variations in muscle or fat mass, or HbA1c, one year of calcium supplementation in elderly women resulted in moderate decreases in TOC and ucOC.