Combined vitamin D and calcium supplementation, or calcium alone, improves sleep quality in individuals with prediabetes
In a 24-week RCT of 212 Chinese adults with prediabetes, the vitamin D plus calcium group showed a significant reduction in total PSQI score compared to pre-intervention levels. Subgroup analyses indicated that calcium supplementation alone improved sleep quality in women, those with low baseline 25(OH)D (<30 ng/mL), and menopausal individuals.
This article is automatically generated from the structured evidence profile behind the claim above. Scores reflect the quality and quantity of available research, not clinical advice.
Combined vitamin D and calcium supplementation, or calcium alone, improves sleep quality in individuals with prediabetes The current body of evidence comprises 1 study, including 1 randomized controlled trial. EvidenceHub rates the overall confidence at 44/100 (low).
The Claim
Combined vitamin D and calcium supplementation, or calcium alone, improves sleep quality in individuals with prediabetes
This conclusion is most relevant to: 212 Chinese adults with prediabetes.
What the Research Shows
The conclusion draws on 1 linked study. Highlights from the cited literature:
- ▸Effects of vitamin D and/or calcium intervention on sleep quality in individuals with prediabetes: a post hoc analysis of a randomized controlled trial. (European journal of nutrition, 2024) —
How It Works
The proposed biological pathway:
- ▸Calcium supplementation may improve sleep efficiency
- ▸Improved sleep efficiency correlates with reduced insulin resistance (negative correlation between change in sleep efficiency and change in insulin efficiency scores, r=-0.264, P=0.007)
- ▸Improved sleep efficiency also correlates with reduced islet beta cell function change (r=-0.304, P=0.002)
- ▸Result: Potential improvement in sleep quality via metabolic pathways
Who Might Benefit
Evidence fit by population:
- ▸212 Chinese adults with prediabetes
Recommended Dose
Vitamin D 1600 IU/day, calcium 500 mg/day
Limitations & Caveats
Important context when interpreting this evidence:
- ▸Post hoc analysis of a randomized controlled trial, not a primary outcome analysis
- ▸Subgroup analyses were exploratory and may be underpowered
- ▸Specific effect sizes (e.g., Cohen's d) not reported, limiting quantitative interpretation
Frequently Asked Questions
What dose of vitamin D and calcium was used in this study?▼
The study used 1600 IU/day of vitamin D and 500 mg/day of calcium, either alone or in combination.
Who benefited most from calcium supplementation for sleep?▼
Subgroup analyses showed improved sleep quality with calcium supplementation in women, individuals with low baseline vitamin D levels (<30 ng/mL), and those in menopause.
How was sleep quality measured in this trial?▼
Sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI), a validated self-report questionnaire.
Was this a primary analysis or a post hoc analysis?▼
This was a post hoc analysis of a randomized controlled trial, meaning the sleep outcome was not the original primary endpoint.
References
- 1.Miao Y, Zhang L, Zhang D, Feng M, Zhang C, Zhao T, Song H, Zhong X, Jiang Z, Li L, Wei X, Li W, Li X. “Effects of vitamin D and/or calcium intervention on sleep quality in individuals with prediabetes: a post hoc analysis of a randomized controlled trial..” European journal of nutrition, 2024. PMID: 38366270 DOI: 10.1007/s00394-024-03345-7