Abstract
To explore the effect of calcium supplementation on the risk of fractures at various sites in older adults based on randomized controlled trials (RCTs). PubMed, Embase, and the Cochrane Library were systematically searched for eligible RCTs from their inception until May 2023. The included trials investigated the effect of calcium supplementation on the risk of fracture in individuals aged 50 years or above, regardless of the use or nonuse of vitamin D. The primary and secondary outcome measures were total, vertebral, nonvertebral, and hip fractures. Twenty-three RCTs involving 70,837 individuals were enrolled. Calcium supplementation demonstrated a significant reduction in the risk of total (RR: 0.93; 95% CI: 0.88-0.99; P=0.019) and nonvertebral (RR: 0.93; 95% CI: 0.87-0.99; P=0.023) fractures. No significant differences were observed in vertebral (RR: 0.87; 95% CI: 0.75-1.01; P=0.074) and hip (RR: 0.90; 95% CI: 0.73-1.12; P=0.355) fractures between calcium and placebo or no treatment. Calcium dose influenced total fracture risk (P=0.008), while history of fracture (P=0.044), calcium dose (P=0.041), and follow-up duration (P=0.031) affected nonvertebral fracture risk. Follow-up duration impacted hip fracture risk (P=0.001). Calcium supplementation can significantly affect the risk of fracture, particularly nonvertebral fractures, in older adults. Level of Evidence I; Therapeutic Studies - Investigating the Results of Treatment.