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Sleep greatly improved by 50,000 IU of vitamin D once every two weeks – RCT Sept 2018

The effect of vitamin D supplement on the score and quality of sleep in 20-50 year-old people with sleep disorders compared with control group

Nutr Neurosci . 2018 Sep;21(7):511-519. doi: 10.1080/1028415X.2017.1317395.
Mohammad Shahi Majid 1, Hosseini Seyed Ahmad 1, Helli Bizhan 1, Haghighi Zade Mohammad Hosein 2, Abolfathi Mohammad 3


  • P1: Comparison mean and SD of sleep score and sleep subgroups score between two group vitamin D recipients and placebo recipients (Mann–Whitney U statistical test for variables).
  • P2: Comparison mean and SD of sleep score and sleep subgroups score between two group of vitamin D recipients and placebo recipients after adjusting for jobs, saturated fatty acids, monounsaturated fatty acids and sun exposure time (ANCONA statistical test)
  • P3: Comparison mean and SD sleep score and sleep subgroups score in each groups at the beginning and the end of the study
  • (Wilcoxon statistical test for variable).
  • PSQI: Pittsburgh Sleep Quality Index

Objectives: Sleep quality may be directly related with vitamin D serum level. Some studies found that people with lower vitamin D serum level experienced a lower sleep quality. Consequently, this study aimed at determining the effect of vitamin D supplements on sleep score and quality in 20-50 year-old people with sleep disorders.

Methods: This double blind, clinical trial was performed in November 2015-February 2016 on 89 people with sleep disorders based on Petersburg's Sleep Index. Patient samples were divided randomly into two groups: intervention and placebo. At the end of the study, the data on 89 subjects (44 in intervention group and 45 people in placebo group) were examined. Intervention group received a 50 000-unit vitamin D supplement, one in a fortnight for 8 weeks. Meanwhile, placebo group received placebo. Before and after intervention, Petersburg's Sleep Quality Questionnaire, International Physical Activity Questionnaire, general information questionnaire, sun exposure, vitamin D serum level and 3-day food record questionnaire were assessed and recorded for all participants. To analyze data, t-test, chi square, ANCOVA, U-Mann-Whitney and Wilcoxon statistical tests were used.

Findings: Based on the results of the present study, at the end of the study sleep score (PSQI) reduced significantly in vitamin recipients as compared with placebo recipients (P < 0.05). This difference was significant even after modifying confounding variables (P < 0.05).

Conclusion: This study shows that the use of vitamin D supplement improves sleep quality, reduces sleep latency, raises sleep duration and improves subjective sleep quality in people of 20-50 year-old with sleep disorder.
 Download the PDF from Sci-Hub via VitaminDWiki

This study is also in VitaminDWiki as Sleeps disorders nicely treated by Vitamin D (50,000 IU twice a month) – RCT May 2017

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Attached files

ID Name Comment Uploaded Size Downloads
19921 Sleep 50K forenightly.jpg admin 07 Aug, 2023 164.13 Kb 106
19920 Sleep better 50K every 2 weeks sci-hub.pdf admin 07 Aug, 2023 245.60 Kb 45