Calcium supplementation for improving bone density in lactating women: a systematic review and meta-analysis of randomized controlled trials

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#adult #bone-density #calcium #calcium-dietary #dietary-supplements

Calcium supplementation for improving bone density in lactating women: a systematic review and meta-analysis of randomized controlled trials

Cai et al., 2020 | Am J Clin Nutr | Meta Analysis

Citation

Cai Guoqi, Tian Jing, ... Wu Feitong. Calcium supplementation for improving bone density in lactating women: a systematic review and meta-analysis of randomized controlled trials. Am J Clin Nutr. 2020-Jul-01;112(1):48-56. doi:10.1093/ajcn/nqaa103

Abstract

BACKGROUND: Clinical trials evaluating the effect of calcium supplementation on bone loss in lactating women have been small, with inconsistent results. OBJECTIVES: We aimed to determine the effect of calcium supplementation on bone mineral density (BMD) in lactating women. METHODS: An electronic search of databases was conducted from inception to January 2020. Two authors screened studies, extracted data, and assessed the risk of bias of eligible studies. Percentage change in BMD was pooled using random-effects models and reported as weighted mean differences (WMDs) with 95% CIs. Risk of bias was assessed using the Cochrane risk of bias tool. RESULTS: Five randomized controlled trials including 567 lactating women were included. All had a high risk of bias. Mean baseline calcium intake ranged from 562 to 1333 mg/d. Compared with control groups (placebo/no intervention), calcium supplementation (600/1000 mg/d) had no significant effect on BMD at the lumbar spine (WMD: 0.74%; 95% CI: -0.10%, 1.59%; I2 = 47%; 95% CI: 0%, 81%; n = 527 from 5 trials) or the forearm (WMD: 0.53%; 95% CI: -0.35%, 1.42%; I2 = 55%; 95% CI: 0%, 85%; n = 415 from 4 trials). BMD at other sites was assessed in single trials: calcium supplementation had a small to moderate effect on total-hip BMD (WMD: 3.3%; 95% CI: 1.5%, 5.1%) but no effect on total body or femoral neck BMD. CONCLUSIONS: Overall, the meta-analysis indicates that calcium supplementation does not provide clinically important benefits for BMD in lactating women. However, there was adequate dietary intake before supplementation in some studies, and others did not measure baseline calcium intake. Advising lactating women to meet the current recommended calcium intakes (with supplementation if dietary intake is low) is warranted unless new high-certainty evidence to the contrary from robust clinical trials becomes available. More research needs to be done in larger samples of women from diverse ethnic and racial groups.This systematic review was registered at www.crd.york.ac.uk/prospero as CRD42015022092.

Key Findings

Five randomized controlled trials including 567 lactating women were included. All had a high risk of bias. Mean baseline calcium intake ranged from 562 to 1333 mg/d. Compared with control groups (placebo/no intervention), calcium supplementation (600/1000 mg/d) had no significant effect on BMD at the lumbar spine (WMD: 0.74%; 95% CI: -0.10%, 1.59%; I2 = 47%; 95% CI: 0%, 81%; n = 527 from 5 trials) or the forearm (WMD: 0.53%; 95% CI: -0.35%, 1.42%; I2 = 55%; 95% CI: 0%, 85%; n = 415 from 4 trial

Outcomes Measured

  • Requires manual extraction

Population

Field Value
Population See abstract
Sample Size 527
Age Range See abstract
Condition See abstract

MeSH Terms

  • Adult
  • Bone Density
  • Calcium
  • Calcium, Dietary
  • Dietary Supplements
  • Female
  • Humans
  • Lactation
  • Randomized Controlled Trials as Topic
  • Young Adult

Evidence Classification

  • Level: Meta Analysis
  • Publication Types: Journal Article, Meta-Analysis, Research Support, Non-U.S. Gov't, Systematic Review
  • Vertical: calcium-bone

Provenance

Source extracted via PubMed E-utilities API on 2026-04-09