Vitamin D Supplementation and Sleep: A Systematic Review and Meta-Analysis of Intervention Studies
Abstract
:1. Introduction
2. Materials and Methods
2.1. Review Design
2.2. Criteria for Study Inclusion
2.3. Search Strategy
2.4. Study Selection
2.5. Data Extraction
2.6. Quality Assessment
2.7. Data Synthesis
2.8. Quality of Reporting
3. Results
3.1. Search Results
3.2. Characteristics of Included Studies
3.3. Assessment of Risk of Bias
3.4. Sleep Quality
3.5. Other Outcomes
- Disturbed sleeping
- Sleepiness
- RLS
3.6. Sleep Problems as Adverse Events of VDS
4. Discussion
Strengths and Limitations
5. Conclusions
Supplementary Materials
Funding
Institutional Review Board Statement
Informed Consent Statement
Conflicts of Interest
References
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First Author, Country | Study Design | Study Population | Age %Male | Control | Co-Intervention | Intervention Duration Daily Dose Equivalent | Compliance | Vitamin D Assessment |
---|---|---|---|---|---|---|---|---|
Randomized, controlled trial | ||||||||
Sleep quality | ||||||||
Ghaderi [25], Iran | Randomized, double-blind, placebo-controlled trial | 68 patients with maintenance methadone treatment referred to a clinic (30 completed the trial: I: n = 30; C: n = 30) | Age: Range: 25–70 Mean ± SD: I: 40.1 ± 9.2 C: 42.5 ± 8.9 %Male: NR | Placebo, capsule | None | Vitamin D (unclear): capsules 12 weeks 3571.42 IU | >90% in both groups | 25(OH)D: commercial ELISA kit |
Maheshwari [41], NR | Pre–post study | 40 patients diagnosed with chronic low back pain | Age: Range: 25–65 %Male: 60% | Self | None | Vitamin D (unclear) 8 weeks NR | NR | NR |
Majid [27], Iran | Randomized, double-blind, placebo-controlled trial | 93 people with sleep disorders (PSQI ≥ 5), but without sleep disorders, not using sleep medications, recruited from a hospital (89 completed the trial: I: n = 44; C: n = 45) | Age: Range: 20–50 Mean ± SD: I: 37.9 ± 9.50 C: 35.5± 10.00 %Male: I: 25.00; C: 22.22 | Placebo, capsule | None | Vitamin D3: edible pearls 8 weeks 3571.42 IU | I: 97.82% C: 97.87% | 25(OH) D: Immunodiagnostic Systems kit |
Mason [28], USA | Randomized, double-blind, placebo-controlled trial | 218 overweight (BMI ≥25 kg/m2) postmenopausal women, with serum 25(OH)D ≥10 to <32 ng/mL undergoing weight loss I: n = 109; C: n = 109 | Age: Range: 50–75 Mean ± SD: 59.6 ± 5.1 %Male: 0% | Placebo, gel capsules | Lifestyle-based weight-loss program including a reduced-calorie diet (1200–2000 kcal/day, <30% daily energy intake from fat) and 225 min/week of moderate-to-vigorous aerobic activity | Vitamin D3, gel capsules 12 months 2000 IU | I: 98% C: 96% | 25(OH)D: DiaSorin LIAISON 25-OH Vitamin D total assay |
Mirzaei [30], Iran | Randomized, double-blind, placebo-controlled trial | 74 fibromyalgia syndrome patients (according to the American College of Rheumatology criteria) with 25(OH)D < 30 ng/mL, recruited from a rheumatology center | Age: Range: 20–70 Mean ± SD: Total: 41.6 ± 10.5 I: 42.1 ± 10.8 C: 41 ± 10.3 %Male: 0% | Placebo | Trazodone 25 mg at bedtime | Vitamin D (unclear) 8 weeks 7142.85 IU | NR | 25(OH)D: commercial radioimmunoassay kit |
Other outcomes | ||||||||
McCarthy [29], Pacific Northwest | Randomized, double-blind, controlled trial | 152 active-duty warfighters, divided into no-treatment group (C) (≥ 30 ng/mL) or treatment group (I) (<30 ng/mL) (131 completed the trial) | Age: Mean ± SD: I: 31.6 ± 8.2 C: 32.8 ± 10.5 %Male: 61.8% | No supplementation | None | Vitamin D3, gel capsules 12 weeks I1: 1000 IU I2: 5000 IU | I1: 84.8% I2: 87.9% C: not required to take pills | 25(OH)D: electrochemiluminescence |
Okereke [32], USA | Randomized, double-blind, placebo-controlled trial | Participants aged ≥50 years in the VITAL-DEP (Vitamin D and Omega-3 Trial-Depression Endpoint Prevention) ancillary study to VITAL, a randomized clinical trial of cardiovascular disease and cancer prevention, without clinically relevant depressive symptoms at baseline I: n = 9181; C: n = 9172 | Age: Mean ± SD: Total: 67.5 ± 7.1 I: 67.5 ± 7.0 C: 67.4 ± 7.1 %Male: Total: 51% I: 50.6%; C: 51.1% | Placebo | None | Vitamin D3, pills Median follow-up: 5.3 years 2000 IU | Adherence rates (taking at least two-thirds of pills as assigned) I: Year 1: 94.8% Year 2: 92.2% Year 3: 91.5% Year 4: 91.4% Year 5: 90.6% C: Year 1: 94.6% Year 2: 92.1% Year 3: 91.0% Year 4: 90.5% Year 5: 89.8% | 25(OH)D: radioimmunoassay |
Rorie [33], USA | Randomized, double-blind, controlled trial | 42 adult patients with physician-diagnosed chronic urticaria, recruited from tertiary care clinics I: n = 21; C: n = 21 | Age: I: Mean: 43.9; Range: 20–72 C: Mean: 43.1; Range: 19–79 %Male: I: 14.2%; C: 28.5% | Low-dose vitamin D3 (600 IU/d) | 10 mg of cetirizine twice daily and increase to 4 times daily as needed, 150 mg of ranitidine twice daily, and 10 mg of montelukast daily. In addition to rescue prednisone use for intolerable or uncontrolled symptoms | Vitamin D3, pills (high dose) 12 weeks 4000 IU | Excellent compliance (1 subject in the low vitamin D3 group showed <80% compliance) | 25(OH)D: Tandem mass spectroscopy |
Zhu [36], China | Randomized, placebo-controlled trial | 158 patients with with 25(OH)D ≤ 75 nmol/L and depression with tied anxiety symptoms recruited through advertisements, assessed by the Mini-International Neuropsychiatric Interview to confirm the diagnosis of major depressive disorders (106 completed the trial: I: n = 62; C: n = 44) | Age: Mean ± SD I: 46.3 ± 9.7 C: 43.3 ± 13.7 %Male: I: 29%; C: 22.7% | Placebo | Fish oil (current intake) | Vitamin D (unclear), per os 6 months 1600 IU | NR | 25(OH)D: commercial radioimmunoassay kit |
Kerley [26], Ireland | Randomized, double-blind, placebo-controlled trial | 26 Caucasian adults with OSA recruited from a sleep clinic (19 completed the trial: 15 on CPAP therapy and 4 CPAP naïve: I: n = 10; C: n = 9) | Age: I: Range: 42–71 Mean ± SD: 56 ± 10 C: Range: 32–68 Mean ± SD: 52 ± 13 %Male: I: 89%; C: 60% | Placebo, capsule | None | Vitamin D3: Capsule 15 weeks 4000 IU | 93% in both groups | Total 25(OH)D: Architect 25(OH)D CMIA |
Sharifan [34], Iran | Randomized, triple-blind, placebo-controlled trial | 29 staff and students of a university, aged 30–50 years, with vitamin D deficiency (<30 ng/mL), abdominal obesity (waist circumference (≥94 cm for men and ≥80 cm for women), and symptoms of insomnia (according to validated Insomnia Severity Index) Milk: I: n = 8; C: n = 8 Yogurt: I: n = 7; C: n = 6 | Age: Mean ± SD: 43.2 ± 6.59 Milk group: I: 39.5 ± 6.23; C: 44.5 ± 5.63 Yogurt group: I: 47.42 ± 6.8; C: 41.5 ± 5.99 %Male: Milk group: I: 20%; C: 80% Yogurt group: I: 57.1%; C: 42.8% | Simple low-fat milk (200 mL/day) Simple low-fat yogurt (150 g/day) | None | I1: Vitamin D3-fortified low-fat milk containing 1500 IU Nan I2: Vitamin D3-fortified low-fat yogurt 10 weeks 1500 IU | NR | 25(OH)D: commercial ELISA kits |
Wali [35], KSA | Randomized, double-blind, placebo-controlled trial | 35 patients with primary RLS identified based on the RLS diagnostic criteria of the IRLSSG and recruited from the Sleep Medicine and Research Center I: n = 17; C: n = 18 | Age: Mean ± SD I: 42.7 ± 4.7 C: 42.4 ± 5.5 %Male: I: 64.7%; C: 72.2% | Placebo | None | Vitamin D3, per os 12 weeks 7142.85 IU | 100% | NR |
Sleep problems as adverse events of VDS | ||||||||
de Koning [24], the Netherlands | Randomized, double-blind, placebo-controlled trial | 155 community-dwelling older people, aged 60–80 years, recruited from the general population or through general practitioners, with depressive symptoms, and serum 25(OH)D between 15 and 50 nmol/L during October–March or between 15 and 70 nmol/L during April–September I: n = 77; C: n = 78 | Age: Median [IQR] I: 67.8 [65.4–71.7] C: 67.3 [63.4–72.0] %Male: I: 41.6%; C: 43.6% | Placebo | Calcium tablet of 500 mg/day in case of <2 dairy consumptions/day Participants were allowed to take a (multi)VDS with a maximum of 400 IU/day in addition to the study tablets | Vitamin D3, tablet 12 months 1200 IU | 87.10% | 25(OH)D: liquid chromatography followed by tandem mass spectrometry |
Mohammadpour [31], Iran | Randomized, double-blind, placebo-controlled trial | 62 children with ADHD (based on DSM-IV criteria), aged 5–12 years, referred from psychiatric centers, without psychiatric nor neurologic comorbidities (54 completed the trial: I: n = 25; C: n = 29) | Age: Mean ± SD: Total: 7.87 ± 1.61 I: 7.70 ± 1.77 C: 8.03 ± 1.44 %Male: I: 71%; C: 77.4% | Placebo | Methylphenidate | Vitamin D (unclear), tablet 8 weeks 2000 IU | 100% | 25(OH)D3: chemiluminescence |
Opportunistic addition to a randomized, controlled trial | ||||||||
Other outcomes | ||||||||
Slow [37], New Zealand | Opportunistic addition to an established randomized, double-blind, placebo-controlled trial | 322 healthy adults already participating in the vitamin D and acute respiratory infections study (VIDARIS) staff or students recruited from a University. (308 completed the trial: I: n = 147; C: n = 146) | Age: Range: 18–67 Mean ± SD: I: 47 ± 10 C: 48 ± 10 %Male: I: 25%; C: 25% | Placebo | None | Vitamin D3, per os 18 months 6557.37 for 2 months, then 3278.68 IU | NR | NR |
Pre–post study | ||||||||
Sleep quality | ||||||||
Eshaghi [39], Iran | Pre–post study | 42 elderly women referred to a sports counseling center, with a PSQI > 11, without sleep apnea, not smoking, and not taking hypnotic drugs (36 completed the trial) | Age: Range: 60–70 %Male: 0% | No supplementation (habitual daily activities) | Vitamin D (unclear) 8 weeks 1000 IU | NR | NR | |
Other outcomes | ||||||||
Guler [40], Turkey | Pre–post study | Cases: 60 patients with ASD according to DSM V criteria, aged between 4 and 10 years Controls: 60 age- and sex-matched apparently healthy children | Age: Mean ± SD: Cases: 7.10 ± 1.50 Controls: 6.93 ± 1.59 %Male: Cases: 73.3%; Controls: 65% | Vitamin D2 3 months Vitamin D according to deficiency level: I1: Participants with 25(OH)D: 20–29 ng/mL: 5000 IU I2: Participants with 25(OH)D < 20 ng/mL: 7142.86 IU | NR | 25(OH)D: radioimmunoassay using commercial kits | ||
Arico [38], Italy | Pre–post study | 5 patients with RLS recruited from a sleep center | Age: NR %Male: 0% | Self | None | Vitamin D3 (unclear) 6 months NR | NR | NR |
Pre–post study, analyzed retrospectively as a case series | ||||||||
Sleep quality | ||||||||
Huang [42], USA | Pre–post study, analyzed retrospectively as a case series by medical record review | 46 veterans with multiple areas of chronic pain and low serum 25(OH)D (<30 ng/mL) at baseline recruited from a major Veterans Affairs Medical Center, divided into vitamin D (1) INS: 25(OH)D: 20–29 ng/mL; and (2) DEF: 25(OH)D: <20 ng/mL (28 completed the trial: INS: n = 15; DEF: n = 13) | Age: Mean ± SD: 46.2 ± 10.8 %Male: 64.3% | Self | None | INS: Vitamin D3: per os DEF: Vitamin D2: per os 12 weeks INS: 1200 IU DEF: 7142.85 IU | NR | 25(OH)D: liquid chromatography–mass spectrometry assay |
First Author, Country | Outcomes Evaluated and Assessment | Baseline 25OHD Level | Endline 25OHD Level | Baseline Outcomes | Endline Outcomes | Conclusion |
---|---|---|---|---|---|---|
Randomized, controlled trial | ||||||
Sleep quality | ||||||
Ghaderi [25], Iran | Sleep quality: PSQI | I: 13.9 ± 4.5 C: 13.5 ± 4.5 (NS difference between I and C) | I: 22.0 ± 7.5 (sig. increase) C: 13.1 ± 5.9 | I: 6.0 ± 2.3 C: 6.6 ± 2.2 | I: 4.5 ± 2.2 (sig. decrease) C: 6.4 ± 3.0 | PSQI sig. decreased in VDS I group compared with C group (−1.5 ± 2.2 vs. −0.2 ± 2.3) |
Maheshwari [41], NR | Sleep quality: PSQI | NR | NR | NR | t-test: 2.965; CI: 1.8312–6.8341; p = 0.004 (sig. differences before and after VDS) | VDS improves sleep in patients with chronic low back pain |
Majid [27], Iran | Sleep quality: PSQI Sleep duration Sleep latency Sleep efficiency: real sleep duration from the whole time passed in bed Sleep disturbances Use of sleep medications Daytime dysfunction: experiencing problems resulted by sleeplessness Subjective sleep quality | I: 25.00 ± 8.95 C: 27.60 ± 8.30 (NS difference between I and C) | I: 37.69 ± 12.25 C: 27.97 ± 7.46 (sig. increase in I, and sig. difference between I and C) | PSQI (score) (NS difference between I and C) I: 9.45 ± 2.44 C: 10.51 ± 3.14 Sleep duration (hour) (sig. higher in I compared with C) I: 5.83 ± 1.15 C: 5.22 ± 1.54 Sleep latency (minute) (NS difference between I and C) I: 49.88 ± 38.99 C: 65.00 ± 47.54 Sleep efficiency (%) (NS difference between I and C) I: 82.58 ± 9.93 C: 78.20 ± 12.90 Sleep disturbances (score) (NS difference between I and C) I: 1.23 ± 0.47 C: 1.40 ± 0.78 Use of sleep medications (time per week) (NS difference between I and C) I: 2.07 ± 1.92 C: 0.77 ± 1.02 Day time dysfunction (score) (NS difference between I and C) I: 1.57 ± 0.99 C: 1.17 ± 0.93 Subjective sleep quality (score) (NS difference between I and C) I: 1.68 ± 0.77 C: 1.57 ± 0.62 | PSQI (score) (sig. lower in I compared with C) I: 6.75 ± 2.97 (sig. decrease) C: 9.73 ± 3.04 Sleep duration (hour) (sig. higher in I compared with C) I: 6.50 ± 1.49 C: 5.21 ± 1.44 Sleep latency (minute) (sig. lower in I compared with C) I: 33.18 ± 27.91 C: 58.57 ± 36.81 Sleep efficiency (%) (NS difference between I and C) I: 86.97 ± 11.39 (sig. decrease) C: 80.89 ± 11.46 Sleep disturbances (score) (NS difference between I and C) I: 1.14 ± 0.46 (NS) C: 1.41 ± 0.65 (NS) Use of sleep medications (time per week) (NS difference between I and C) I: 1.07 ± 0.94 (sig. decrease) C: 1.20 ± 0.99 Day time dysfunction (score) (NS difference between I and C) I: 0.70 ± 0.96 (sig. decrease) C: 0.75 ± 0.98 Subjective sleep quality (score) (sig. lower in I compared with C) I: 1.18 ± 0.62 (sig. decrease) C: 1.46 ± 0.58 | Reduced PSQI (improved sleep score), reduced sleep latency, increased sleep duration, and subjective sleep quality with VDS. NS difference in sleep efficiency, sleep disturbances, and use of sleep medications |
Mason [28], USA | Sleep quality: PSQI | NR | NR | NR | NR | NS change in overall sleep quality between VDS I and C groups A greater magnitude of change in serum 25(OH)D was associated with an increased need to take medications to sleep and overall worse sleep quality Deterioration in total PSQI among women who became vitamin D replete (≥32 ng/mL) compared with those who remained <32 ng/mL (despite VDS) VDS of 2000 IU/d may result in overall worse sleep quality for postmenopausal women with low circulating vitamin D undergoing weight loss |
Mirzaei [30], Iran | Sleep quality: PSQI | I: 11.4 ± 6.7 C: 13.4 ± 7.3 | I: 33.5 ± 12.2 (sig. higher in I compared with C) C: 13.3 ± 7.2 | I: 10 ± 3.3 C: 10.75 ± 4.4 | I: 6.2 ± 2.2 C: 8.2 ± 3.7 (sig. lower in I compared with C) | Considerable improvements were observed in the PSQI score of the both study groups; yet there was a sig. greater decrease in mean PSQI score in the I compared with C group |
Other outcomes | ||||||
McCarthy [29], Pacific Northwest | Sleep-related impairment: Questions from the National Institutes of Health Patient-Reported Outcomes Measurement Information System | I1: 22.2 ± 5.0 I2: 22.9 ± 4.7 C: 37.8 ± 5.6 | I1: 30.80 ± 10.0 I2: 40.15 ± 7.5 (sig. higher in I2 compared with I1 and C) C: 34.46 ± 9.9 | I1: 53.0 ± 7.0 I2: 48.3 ± 9.5 C: 51.5 ± 7.0 | I1: 49.5 ± 9.5 I2: 45.2 ± 8.4 C: 49.3 ± 8.2 | Statistically significant improvements seen across groups and over time |
Okereke [32], USA | Sleep difficulty (sleep problems) as specific depressive feature (item-level symptom) from the 8 item Patient Health Questionnaire depression scale: Trouble falling or staying asleep, or sleeping too much | 25(OH)D < 20 ng/mL I: 11.0% C: 12.3% Mean ± SD I: 31.2 ± 9.8 C: 31.1 ± 10.0 | NR | NR | NR | NS differences in likelihood of sleep problems in the I compared with C group Adjusted differences in change in likelihood of PHQ-8 item-level symptoms, comparing vitamin D3 to Placebo: Sleep problems: Likelihood ratio: 95% CI: 1.00 (0.89–1.12) Analyses were from repeated measures logistic regression models, with follow-up time modeled as an indicator; models were controlled for age, sex, and n-3 fatty acid randomization group. Results show likelihood ratios and 95% confidence intervals (95% CIs), which reflect differences in the change in likelihood of burden from each PHQ-8 item-level symptom, comparing vitamin D3 to placebo treatment group. Differences reflect the average effect over all follow-up times since baseline |
Rorie [33], USA | Nights of hives and sleep interference: from the Urticaria Symptom Severity scores | Mean(SE) C: 37.1(3.4) I: 28.8(2.2) | Mean(SE) C: 35.8(2.3) I: 56.0(3.9) (sig. higher in I compared with C) | NR | NR | Beneficial trends for sleep quality and towards decreased interference with sleep were observed with high vitamin D3 |
Zhu [36], China | Sleep disorder: NR | I: 15.66 ± 4.20 C: 16.86 ± 5.04 (NS difference between I and C group) | NR | NR | NR | Between-group linear mixed-model analysis showed sig. decrease in Sleep disorder (β: −0.588; 95% CI: −1.061,−0.115), that was rendered NS after controlling for confounding variables (β: −0.355; 95% CI: −0.963,0.227) |
Kerley [26], Ireland | Sleepiness: ESS | I: 13.38 ± 4.64 C: 16.58 ± 8.81 (NS difference between I and C) | I: 40.38 ± 15.98 (sig. increase) C: 17.22 ± 8.57 | I: 11.00 ± 5.00 C: 10.00 ± 6.00 (NS difference between I and C) | I: 6.00 ± 2.00 C: 7.00 ± 5.00 (NS difference between I and C) | No difference in ESS between the VDS I group and C group |
Sharifan [34], Iran | Changes in sleepiness symptoms: Insomnia Severity Index | Milk I: 15.03 ± 3.91 C: 14.9 ± 7.34 (NS difference between I and C group) Yogurt I: 15.82 ± 4.09 C: 16.72 ± 2.96 (NS difference between I and C group) | Milk: I: 18.57 (sig. increase compared with baseline) C: 14.66 Yogurt: I: 19.93 (sig. increase compared with baseline) C: 16.26 (SD not reported) | Milk: I: 18.5 ± 3.33 C: 17.25 ± 2.34 Yogurt: I: 13.28 ± 5.12 C: 13 ± 3.54 | Milk I: 13.62 ± 3.29 (sig. increase compared with baseline) C: 16.5 ± 4.02 (NS difference compared with baseline) Yogurt I: 17.57 ± 13.28 (NS difference compared with baseline) C: 16.66 ± 1.36 (NS difference compared with baseline) | Fortified low-fat milk containing 1500 IU vitamin D3 can improve insomnia symptoms |
Wali [35], KSA | RLS severity: IRLSSG rating scale | I: 17.06 ± 12.6 C: 22.95 ± 16.98 (NS difference between I and C group) | I: 6.09 ± 15.38 (sig. higher in I compared with C group) C: 21.23 ± 13.74 | Total I: 14.60 ± 4.5 C: 16.11 ± 6.2 In DEF patients I: 14.82 ± 5.2 C: 16.81 ± 6.3 | Total: I: 14.5 ± 08.2 (NS difference compared with baseline) C: 10.3 ± 11.1 (sig. decrease compared with baseline) In DEF patients I: 13.8 ± 8.9 (NS difference compared with baseline) C: 7.8 ± 13.9 (sig. decrease compared with baseline) | NS difference in RLS severity score with VDS suggesting that VDS does not improve RLS symptoms |
Sleep problems as adverse events of VDS | ||||||
de Koning [24], the Netherlands | Sleep problems as adverse event: registered by telephone or face-to-face contact | median [IQR] I: 18.42 [13.02–22.83] C: 17.68 [14.42–22.13] (significance NR) | mean ± SD I: 34.05 ± 6.41 C: 17.22 ± 7.21 (sig. difference between I and C) | NA (sleep problems as adverse event of VDS) | I: n = 1 C: n = 5 (NS difference between I and C) | NS difference in sleep problems as adverse effect of VDS in community-dwelling people with depressive symptoms |
Mohammadpour [31], Iran | Sleep problems as adverse events: questionnaire | mean ± SD I: 15.792 ± 5.259 C: 12.979 ± 5.804 (NS difference between I and C) | mean ± SD: I: 34.63 ± 9.54 (sig. increase between baseline and endline) C: 11.22 ± 5.11 (NS difference between baseline and endline) Sig. difference between I and C | NA (sleep problems as adverse event of VDS) | Rate I: 4 C: 1 (NS difference between I and C) | NS difference in sleep problems as adverse effect of VDS as adjunctive therapy in children with ADHD |
Opportunistic addition to a randomized, controlled trial | ||||||
Other outcomes | ||||||
Slow [37], New Zealand | Specific questionnaire about disruptions in sleeping patterns as a consequence of the earthquake on the 22nd February 2011 | I: 29.24 ± 8.81 C: 28.44 ± 8.81 | NR | NR | I: 79% C: 70% (NS difference between I and C) | VDS did not reduce the adverse impact of earthquakes in healthy adults |
Pre–post study | ||||||
Sleep quality | ||||||
Eshaghi [39], Iran | Sleep quality: PSQI | NR | NR | Mean ± SD I: 12.55 ± 1.01 C: 12.55 ± 1.01 | Mean ± SD I: 10.11 ± 1.26 (significant difference compared with baseline) C: 12.44 ± 0.88 (contradictory evidence regarding C group between written (NS difference) and tabulated (sig. difference) results) | Sleep quality sig. improved by 19.1% with VDS |
Other outcomes | ||||||
Guler [40], Turkey | Sleep habits and disorders: short version of the CSHQ with a higher score reflecting more disturbed sleep behavior | Cases: 25(OH)D < 10 ng/mL: 23.3% 25(OH)D: 10–30 ng/mL: 45% 25(OH)D > 30 ng/mL: 31.7% mean ± SD: 25.58 ± 10.31 Controls: 25(OH)D < 10 ng/mL: 23.3% 25(OH)D: 10–30 ng/mL: 38.3% 25(OH)D > 30 ng/mL: 38.3% mean ± SD: 25.35 ± 9.92 (NS difference between Cases and Controls) In DEF participants: 25(OH)D: Cases: 19.68 ± 6.22 Controls: 19.21 ± 7.35 | Cases: 25(OH)D < 10 ng/mL: 0% 25(OH)D: 10–30 ng/mL: 11.7% 25(OH)D > 30 ng/mL): 88.3% mean ± SD: 37.27 ± 6.51 Controls: 25(OH)D < 10 ng/mL: 0% 25(OH)D: 10–30 ng/mL: 6.7% 25(OH)D > 30 ng/mL: 93.3% mean ± SD: 37.15 ± 6.78 (NS difference between Cases and Controls) In DEF participants: 25(OH)D: Cases: 37.26 ± 7.34; sig Controls: 39.13 ± 7.74; sig | CSHQ total score Cases: <41: 21.7%; ≥41: 78.3% Controls: <41: 66.7%; ≥41: 33.3% mean ± SD total sleep time (hours) Cases: 8.10 ± 0.97 Controls: 9.24 ± 0.89 In DEF participants Total score Cases: 52.05 ± 8.24 Controls: 42.00 ± 4.78 Bedtime resistance Cases: 11.24 ± 2.49 Controls: 7.38 ± 1.01 Sleep-onset delay Cases: 2.32 ± 0.79 Controls: 1.86 ± 0.89 Sleep duration Cases: 5.41 ± 0.92 Controls: 4.41 ± 0.98 Sleep anxiety Cases: 7.73 ± 2.59 Controls: 4.41 ± 0.80 Night wakings Cases: 5.59 ± 1.61 Controls: 4.11 ± 1.39 Parasomnias Cases: 9.80 ± 2.52 Controls: 8.51 ± 1.76 Sleep-disordered breathing Cases: 3.63 ± 0.73 Controls: 3.59 ± 0.90 Daytime sleepiness Cases: 10.44 ± 1.84 Controls: 9.89 ± 1.85 Total sleep time Cases: 8.16 ± 0.89 Controls: 9.11 ± 0.89 | CSHQ total score Cases: <41: 28.3%; ≥41: 71.7% Controls: <41: 86.7%; ≥41: 13.3% mean ± SD total sleep time (hours) Cases: 8.58 ± 0.96 Controls: 9.38 ± 0.88 (sleep time sig. different between Cases and Controls) In DEF participants Total score Cases: 46.43 ± 8.04; sig Controls: 37.56 ± 2.80; sig Bedtime resistance Cases: 10.17 ± 2.66; sig Controls: 7.21 ± 0.75; NS Sleep-onset delay Cases: 1.82 ± 0.80; sig Controls: 1.08 ± 0.36; sig Sleep duration Cases: 4.70 ± 0.95; sig Controls: 4.18 ± 0.90; sig Sleep anxiety Cases: 6.78 ± 2.35; sig Controls: 4.05 ± 0.4; sig Night wakings Cases: 4.24 ± 1.59; sig Controls: 3.32 ± 0.62; sig Parasomnias Cases: 8.75 ± 1.84; sig Controls: 7.16 ± 0.44; sig Sleep-disordered breathing Cases: 3.41 ± 059; sig Controls: 3.40 ± 0.76; sig Daytime sleepiness Cases: 10.17 ± 1.93; NS Controls: 9.21 ± 1.08; sig Total sleep time Cases: 8.63 ± 0.85; sig Controls: 9.29 ± 0.89; sig | VDS may be beneficial in ASD patients and healthy individuals with sleep disturbances |
Arico [38], Italy | RLS severity: IRLS-RS | 10.3 | 30.4 (no information on statistical significance) | 19.8 | 8.6 (no information on statistical significance) | VDS has a therapeutic effect in decreasing RLS severity |
Pre–post study, analyzed retrospectively as a case series | ||||||
Sleep quality | ||||||
Huang [42], USA | Sleep quality: PSQI Sleep latency: #2 “how long has it usually taken you to fall asleep each night” of the PSQI Sleep duration: #4 “how many hours of actual sleep did you get at night” of the PSQI Sleep efficiency: #4 + #1 “what time have you usually gone to bed at night” + #3 “what time have you usually gotten up in the morning” of the PSQI | Total: 18.57 ± 5.42 INS: 22.73 ± 1.83 DEF: 13.77 ± 3.94 | Total: 26.00 ± 8.38 (sig. increase) INS: 29.60 ± 11.67 DEF: 24.00 ± 5.79 | Global PSQI score Total: 13.46 ± 4.92 INS: 12.27 ± 5.55 DEF: 14.85 ± 3.83 Sleep latency (min) Total: 67.22 ± 56.13 INS: 41.61 ± 48.21 DEF: 94.81 ± 52.15 Sleep duration (h) Total: 4.59 ± 1.84 INS: 5.33 ± 1.88 DEF: 3.73 ± 1.41 Sleep efficiency (%) Total: 59.79 ± 25.31 INS: 66.97 ± 23.7 DEF: 52.61 ± 25.70 | Global PSQI score Total: 12.22 ± 4.61 (sig. decrease) INS: 11.29 ± 4.66 DEF: 13.23 ± 4.51 (sig. decrease) Sleep latency (min) Total: 57.86 ± 44.03 (sig. decrease) INS: 39.83 ± 39.05 DEF: 78.65 ± 41.33 (sig. decrease) Sleep duration (h) Total: 5.30 ± 1.57 (sig. decrease) INS: 5.90 ± 1.55 (sig. decrease) DEF: 4.62 ± 1.33 (sig. decrease) Sleep efficiency (%) Total: 66.62 ± 18.61 (sig. increase) INS: 70.34 ± 17.76 DEF: 62.33 ± 19.34 (sig. increase) | Sig. improvement in overall sleep quality, sleep latency, sleep duration, and sleep efficiency in veterans with multiple areas of chronic pain with VDS (after controlling for potential confounders improvement in sleep efficiency became borderline significant) The magnitudes of sleep improvement in latency, duration, and efficiency were all larger in the DEF subgroup; however, the difference in improvements between the subgroups was NS except for sleep latency |
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Abboud, M. Vitamin D Supplementation and Sleep: A Systematic Review and Meta-Analysis of Intervention Studies. Nutrients 2022, 14, 1076. https://doi.org/10.3390/nu14051076
Abboud M. Vitamin D Supplementation and Sleep: A Systematic Review and Meta-Analysis of Intervention Studies. Nutrients. 2022; 14(5):1076. https://doi.org/10.3390/nu14051076
Chicago/Turabian StyleAbboud, Myriam. 2022. "Vitamin D Supplementation and Sleep: A Systematic Review and Meta-Analysis of Intervention Studies" Nutrients 14, no. 5: 1076. https://doi.org/10.3390/nu14051076
APA StyleAbboud, M. (2022). Vitamin D Supplementation and Sleep: A Systematic Review and Meta-Analysis of Intervention Studies. Nutrients, 14(5), 1076. https://doi.org/10.3390/nu14051076