Evidence map›Paper›PMID 34649591›Full record

SynthesisJournal of orthopaedic surgery and research2021

The combined effect of vitamin K and calcium on bone mineral density in humans: a meta-analysis of randomized controlled trials.

Liyou Hu, Jindou Ji, Dong Li, Jing Meng, Bo Yu

Open access · goldAbstract readMeta-AnalysisReview
In one paragraph

Synthesis in Journal of orthopaedic surgery and research, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 16 papers, 7 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
16citing papers in PubMed, 7 pooled it
2.3field-weighted citation impact, top 13% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

16 citing papers in PubMed, 7 syntheses or guidelines pooled it, 27 citations in OpenAlex.

  1. Pooled it
  2. Pooled it
  3. Pooled it
  4. [Exercise therapy and basic treatment for osteoporosis].Orthopadie (Heidelberg, Germany) · 2023
    Guideline
  5. Pooled it
  6. Pooled it
  7. Pooled it
  8. Review
  9. Article
  10. Supplements for bone health.Archives of endocrinology and metabolism · 2025
    Review
  11. Review
  12. Article
  13. Review
  14. Roles of vitamin K‑dependent protein in biomineralization (Review).International journal of molecular medicine · 2024
    Review
  15. Role of vitamins beyond vitamin DInternational journal of molecular medicine · 2024
    Review
  16. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

5 authors at 2 institutions in 1 country.

Liyou HuShandong University of Traditional Chinese Medicine, Jinan, 250014, China.
Jindou JiShandong University of Traditional Chinese Medicine, Jinan, 250014, China.
Dong LiShandong University of Traditional Chinese Medicine, Jinan, 250014, China.
Jing MengShandong University of Traditional Chinese Medicine, Jinan, 250014, China.
Bo YuDepartment of Orthopaedics, Affiliated Hospital of Shandong University of Traditional Chinese Medicine, Jingshi Road 16369, Jinan, 250014, China. ybshengzhongyi@126.com.
Shandong University of Traditional Chinese Medicine · CNAffiliated Hospital of Shandong University of Traditional Chinese Medicine · CN

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundWith the increasing incidence of osteoporosis, vitamin K and calcium have been linked to bone mineral density (BMD) and undercarboxylated osteocalcin (UcOC) in many studies, but the results of studies of the combined effect of vitamin K and calcium on BMD and UcOC in humans have been inconsistent. We conducted a systematic review of randomized controlled trials to assess the effect of this combination treatment on BMD and UcOC in humans.

methodsA search for articles was conducted using PubMed, Embase, and the Cochrane Library database up to March 2021 (no language restrictions). We also reviewed the reference lists of the relevant publications and reviews to locate additional publications. The standard mean difference (SMD) was used as the primary measure of effect size. Our main endpoints were lumbar BMD, femoral neck BMD, hip BMD, total femoral BMD, and UcOC from baseline to end point. We performed subgroup analysis, heterogeneity testing, and assessment of publication bias.

resultsA total of 1346 patients from 10 randomized controlled trials were included in the meta-analysis. The forest plot analysis revealed that vitamin K combined with calcium was associated with a higher lumbar spine BMD compared to controls. The SMD was 0.20 [95% confidence interval (CI): 0.07 to 0.32]. Vitamin K and calcium supplementation led to a significant decrease in UcOC (SMD: - 1.71, 95% CI: - 2.45 to - 0.96). Subgroup analysis showed that vitamin K2 and vitamin K1 had SMDs of 0.30 (95% CI: 0.10 to 0.51) and SMDs of 0.14 (95% CI: - 0.02 to 0.29), and calcium dosages of ≤ 1000 mg/d or > 1000 mg/d had SMDs of 0.19 (95% CI: 0.05 to 0.32) and 0.26 (95% CI: - 0.04 to 0.55).

conclusionThe combination of vitamin K and calcium has a positive effect on lumbar BMD and decreases the level of UcOC. Registration: The protocol for this meta-analysis was registered at the International Prospective Register of Systematic Reviews (CRD42021251825).

Indexed as

Bone DensityCalciumHumansOsteocalcinRandomized Controlled Trials as TopicSystematic Reviews as TopicVitamin KCalciumOsteocalcinVitamin KBone mineral densityCalciumSystematic reviewUcOCVitamin K

Identifiers

PMID34649591
PMCPMC8515712
OpenAlexW3206831688

What Socratic holds

Textmetadata
LicenceCC BY
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the Socratic graph.