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Daily vitamin D3 supplementation improves overall sleep quality more than weekly supplementation in vitamin D3-deficient adults

In a randomized controlled trial of 87 vitamin D3-deficient adults, daily supplementation (6000 IU/day for 8 weeks) significantly improved PSQI total score compared to weekly supplementation (60,000 IU/week) (8.46 vs 9.93, P=0.024). Daily dosing also improved sleep duration (0.93 vs 1.55, P=0.002) and daytime dysfunction (0.67 vs 1.11, P=0.007), while weekly dosing was better for reducing need for sleep medication (0.13 vs 0.37, P=0.034).

Last updated: Aug 22, 2026•1 RCTs•📖 Read as article →

Evidence Score

Evidence Score44/100
Human RCT★★☆☆☆
Meta-analysis☆☆☆☆☆
Mechanism★★★★★
Safety★★★★☆
Confidencelow

Study Evidence

Study 1. Effect of Vitamin D3 Supplementation on Sleep Quality in Deficient Adults: A Randomized Controlled Trial.

observational

Lalitha LP, Rangaiah P, Mehta A, Javali M, Acharya PT, Somanna SN · Neurology India (2026)

Participants: N/A
Duration: 8 weeks
Intervention: Daily vitamin D3 supplementation (6000 IU/day) for 8 weeks compared to weekly vitamin D3 supplementation (60,000 IU/week) for 8 weeks
Outcome: Sleep quality measured by Pittsburgh Sleep Quality Index (PSQI) total score and subcomponents (sleep duration, daytime dysfunction, need for sleep medication)
Effect Size: N/A (only P-values reported)
Population: Adults with vitamin D3 deficiency (mean age 39.26 years, 71% female, n=87)

Result:

PubMed: 42619227DOI: 10.4103/neurol-india.Neurol-India-D-26-00162

Mechanism Graph

Vitamin D3 supplementation increases serum vitamin D3 levels
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Vitamin D3 receptors in brain regions involved in sleep regulation are activated
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Improved vitamin D3 status may modulate sleep-related neurotransmitters and circadian rhythms
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Result: Improved overall sleep quality, sleep duration, and daytime dysfunction

Limitations

  • ⚠Single-center, single-blinded design may introduce bias
  • ⚠Subjective sleep quality measured via PSQI only, no objective measures (e.g., polysomnography)
  • ⚠Short duration (8 weeks) may not capture long-term effects
  • ⚠No placebo control group, only comparison between two dosing regimens

Frequently Asked Questions

What is the recommended dose of vitamin D3 for improving sleep quality in deficient adults?▼

The study suggests daily supplementation of 6000 IU/day for 8 weeks is more effective than weekly dosing for overall sleep quality, but individual dosing should be guided by a healthcare provider.

How does vitamin D3 affect sleep quality?▼

Vitamin D3 may influence sleep through receptors in brain regions regulating sleep, and by modulating neurotransmitters and circadian rhythms, though the exact mechanism is not fully understood.

Is daily or weekly vitamin D3 supplementation better for sleep?▼

Based on this trial, daily supplementation (6000 IU/day) improved overall PSQI score, sleep duration, and daytime dysfunction more than weekly supplementation (60,000 IU/week), though weekly dosing was better for reducing need for sleep medication.

Who was studied in this vitamin D3 sleep trial?▼

The study included 87 adults with vitamin D3 deficiency, with a mean age of 39.26 years and 71% female, from a single center in India.

Products

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References

  1. 1.Lalitha LP, Rangaiah P, Mehta A, Javali M, Acharya PT, Somanna SN. "Effect of Vitamin D3 Supplementation on Sleep Quality in Deficient Adults: A Randomized Controlled Trial.." Neurology India, 2026. PMID: 42619227 DOI: 10.4103/neurol-india.Neurol-India-D-26-00162
Disclaimer: This content is for educational purposes only and is not medical advice. Evidence scores reflect the quality and quantity of available research, not clinical recommendations. Always consult a healthcare professional before starting any supplement or intervention.