Short-Term Effects of Kefir-Fermented Milk Consumption on Bone Mineral Density and Bone Metabolism in a Randomized Clinical Trial of Osteoporotic Patients

PLoS One. 2015 Dec 10;10(12):e0144231. doi: 10.1371/journal.pone.0144231. eCollection 2015.


Milk products are good sources of calcium that may reduce bone resorption and help prevent bone loss as well as promote bone remodeling and increase bone formation. Kefir is a product made by kefir grains that degrade milk proteins into various peptides with health-promoting effects, including antithrombotic, antimicrobial and calcium-absorption enhancing bioactivities. In a controlled, parallel, double-blind intervention study over 6 months, we investigated the effects of kefir-fermented milk (1,600 mg) supplemented with calcium bicarbonate (CaCO3, 1,500 mg) and bone metabolism in 40 osteoporosis patients, and compared them with CaCO3 alone without kefir supplements. Bone turnover markers were measured in fasting blood samples collected before therapy and at 1, 3, and 6 months. Bone mineral density (BMD) values at the spine, total hip, and hip femoral neck were assessed by dual-energy x-ray absorptiometry (DXA) at baseline and at 6 months. Among patients treated with kefir-fermented milk, the relationships between baseline turnover and 6 months changes in DXA-determined BMD were significantly improved. The serum β C-terminal telopeptide of type I collagen (β-CTX) in those with T-scores > -1 patients significantly decreased after three months treatment. The formation marker serum osteocalcin (OC) turned from negative to positive after 6 months, representing the effect of kefir treatment. Serum parathyroid hormone (PTH) increased significantly after treatment with kefir, but decreased significantly in the control group. PTH may promote bone remodeling after treatment with kefir for 6 months. In this pilot study, we concluded that kefir-fermented milk therapy was associated with short-term changes in turnover and greater 6-month increases in hip BMD among osteoporotic patients.

Trial registration: NCT02361372.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial

MeSH terms

  • Absorptiometry, Photon
  • Aged
  • Bone Density*
  • Bone and Bones / metabolism*
  • Calcium / blood
  • Calcium Carbonate / therapeutic use
  • Collagen Type I / blood
  • Cultured Milk Products*
  • Dietary Supplements
  • Double-Blind Method
  • Female
  • Humans
  • Male
  • Middle Aged
  • Osteocalcin / blood
  • Osteoporosis / diet therapy*
  • Osteoporosis / metabolism
  • Osteoporosis / pathology
  • Parathyroid Hormone / blood
  • Peptides / blood
  • Placebo Effect
  • Treatment Outcome


  • Collagen Type I
  • Parathyroid Hormone
  • Peptides
  • collagen type I trimeric cross-linked peptide
  • Osteocalcin
  • Calcium Carbonate
  • Calcium

Associated data


Grants and funding

This research was supported in part by grants NSC-99-2324-B-005-017-CC1, NSC-101-2324-B-005-002-CC1, MOST-101-2313-B-005-014-MY3, and MOST-104-2313-B-005-043-MY3 from the National Science Council and the Ministry of Education, Taiwan, Republic of China, under the Aiming for the Top University plan (ATU-103-S0508). The funders had no role in this design, data collection and analysis, decision to publish, or preparation of the manuscript.