The Study
Association between calcium intake and sleep quality: a systematic review
This study looked at lots of other studies that asked people how much calcium they eat and how well they sleep. It found that people who eat more calcium sometimes say they sleep better, but that doesn’t mean calcium is making them sleep better — maybe they just live healthier lives overall.
Analysis score
Maximum 100 for a systematic review.
Where the score came from
Scientists looked at studies about whether people who eat more calcium (like from milk or cheese) sleep better or longer.
Where does this study sit?
Systematic Reviews & Meta-analyses
Max 100Randomized Trials
Max 90Cohort Studies
Max 72Case-Control
Max 58Cross-Sectional
Max 44Case Reports & Series
Max 30Expert Opinion
Max 545 / 100
Quality score
Groups of people are followed over time to see who develops an outcome. Strong for identifying risk factors and associations, but cannot prove causation as firmly as RCTs.
Key takeaways
Summary
Based on the study abstract and findings.
- 1The differences in calcium intake were small (tens to hundreds of mg), and sleep was self-reported, so it’s unclear if calcium actually causes better sleep or if other habits (like diet or lifestyle) explain it.
- 2People who ate more calcium tended to report better sleep — for example, those with good sleep ate about 350 mg/day more calcium than those with poor sleep, and doubling calcium intake was linked to 22% lower chance of trouble falling asleep.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
BMJ Nutrition, Prevention & Health
Year
2025
Authors
A. Isoda, J. Kiriya, M. Jimba
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.