Effects of Potassium Citrate Supplementation on Bone Turnover Markers in Postmenopausal Women: A GRADE-Assessed...

Osteoporosis and osteopenia are major health burdens among postmenopausal women. Potassium citrate, which is an alkaline salt that neutralizes the acid load in the diet is a preventive measure for bone loss. We conducted a systematic review and meta-analysis following PRISMA guidelines. We searched PubMed, Web of Science, Scopus, and Cochrane CENTRAL for randomized controlled trials examining potassium citrate supplementation effects on bone health outcomes in postmenopausal women. Random-effects models calculated mean differences with 95% confidence intervals. Trial sequential analysis assessed evidence sufficiency. Five RCTs involving 401 postmenopausal women were included. Potassium citrate significantly reduced urinary N-terminal telopeptide (NTX) at 1 month compared with placebo (MD = - 4.05 nmol BCE/mmol creatinine; 95% CI - 8.05 to - 0.05; p = 0.0474; I² = 0%). However, no significant effects were observed on serum C-terminal telopeptide (CTX) at 3 or 6 months, or on procollagen type 1 N-terminal propeptide (P1NP) at 3, 6, or 12 months. Potassium citrate significantly increased urinary potassium excretion at both 3 months and 6 months, while urinary calcium, serum calcium, parathyroid hormone, and urinary pH showed no statistically significant differences between groups. Trial sequential analysis indicated that the available evidence for P1NP at 3 and 6 months remains inconclusive, with the accrued sample size below the required information size. Potassium citrate supplementation showed a selective reduction in urinary NTX, suggesting a potential effect on bone resorption. However, no consistent significant effects were observed on other bone turnover markers, including CTX and P1NP, or on calcium-related biochemical outcomes. The clinical relevance of this finding remains uncertain, and further large, well-designed trials with longer follow-up are needed to clarify the role of potassium citrate in preventing postmenopausal bone loss.