Vitamin E supplementation in people with cystic fibrosis
Information
- DOI:
- https://doi.org/10.1002/14651858.CD009422.pub4Copy DOI
- Database:
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- Cochrane Database of Systematic Reviews
- Version published:
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- 06 September 2020see what's new
- Type:
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- Intervention
- Stage:
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- Review
- Cochrane Editorial Group:
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Cochrane Cystic Fibrosis and Genetic Disorders Group
- Copyright:
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- Copyright © 2020 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.
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Authors
Contributions of authors
Peter Okebukola conceived of and wrote the text of the protocol and review alongside Sonal Kansra with comments from Joanne Barratt.
Sources of support
Internal sources
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No sources of support supplied
External sources
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National Institute for Health Research, UK
This systematic review was supported by the National Institute for Health Research, via Cochrane Infrastructure funding to the Cochrane Cystic Fibrosis and Genetic Disorders Group.
Declarations of interest
All authors: none known.
Acknowledgements
We would like to thank Larissa Shamseer for her input into an early draft of the protocol and also Helen McCabe who was an author on the published protocol. Thanks also to Nikki Jahnke for all her help with editing the review and other administrative matters. Finally we would like to thank the authors of the included Keljo study for providing additional data.
This project was supported by the National Institute for Health Research, via Cochrane Infrastructure funding to the Cochrane Cystic Fibrosis and Genetic Disorders Group. The views and opinions expressed therein are those of the authors and do not necessarily reflect those of the Systematic Reviews Programme, NIHR, NHS or the Department of Health.
Version history
| Published | Title | Stage | Authors | Version |
| 2020 Sep 06 | Vitamin E supplementation in people with cystic fibrosis | Review | Peter O Okebukola, Sonal Kansra, Joanne Barrett | |
| 2017 Mar 06 | Vitamin E supplementation in people with cystic fibrosis | Review | Peter O Okebukola, Sonal Kansra, Joanne Barrett | |
| 2014 Dec 09 | Vitamin E supplementation in people with cystic fibrosis | Review | Peter O Okebukola, Sonal Kansra, Joanne Barrett | |
| 2011 Nov 09 | Vitamin E supplementation in people with cystic fibrosis | Protocol | Peter O Okebukola, Sonal Kansra, Helen McCabe | |
Differences between protocol and review
We originally planned to present all formulations of vitamin E supplements as a single intervention, but in the full review we have presented the comparisons of water‐soluble vitamin E supplements versus control and fat‐soluble vitamin E supplements versus control separately.
Following peer review comments, we updated our planned methods and for multi‐arm studies, we now plan to include data from both arms of any such studies.
Keywords
MeSH
Medical Subject Headings (MeSH) Keywords
- alpha-Tocopherol [administration & dosage];
- Bias;
- Cystic Fibrosis [*blood];
- *Dietary Supplements;
- Exocrine Pancreatic Insufficiency [complications];
- Placebos [administration & dosage];
- Randomized Controlled Trials as Topic;
- Vitamin E [*administration & dosage, blood, chemistry];
- Vitamin E Deficiency [prevention & control];
- Vitamins [*administration & dosage, chemistry];
Medical Subject Headings Check Words
Adolescent; Adult; Child; Child, Preschool; Female; Humans; Infant; Male;
PICOs
Comparison 1: Water‐miscible vitamin E supplementation versus control, Outcome 1: Serum vitamin E levels
Comparison 1: Water‐miscible vitamin E supplementation versus control, Outcome 2: Weight
Comparison 2: Fat‐soluble vitamin E supplementation versus control, Outcome 1: Serum vitamin E levels
| Water‐soluble vitamin E compared with control for cystic fibrosis | ||||||
| Patient or population: children and adults with cystic fibrosis Settings: outpatients Intervention: 10 mg/kg/day of oral vitamin E tocopherol (d‐l alpha‐tocopheryl acetate) in water‐miscible solution Comparison: no supplementation (Harries 1969; Wong 1988) or placebo (Levin 1961) | ||||||
| Outcomes | Illustrative comparative risks* (95% CI) | Relative effect | No of participants | Quality of the evidence | Comments | |
|---|---|---|---|---|---|---|
| Assumed risk | Corresponding risk | |||||
| No supplementation or placebo | Water‐soluble oral vitamin E | |||||
| Vitamin E total lipid ratio | This outcome was not measured. | |||||
| Vitamin E levels in serum: umol/L Follow‐up: 6 months | The mean serum level of vitamin E in the control group was 4.6 umol/L. | The mean serum level of vitamin E in the intervention group was 19.74 umol/L higher (13.48 umol/L higher to 26.00 umol/L higher). | MD 19.74 (13.48 to 26.00). | 45 | ⊕⊕⊝⊝ | Only 1 study reported this outcome at the 6‐month time point ( Levin 1961 ). 2 further studies reported serum levels of vitamin E at 1 month and found a statistically significant result in favour of the supplemental group, MD 17.66 (95% CI 10.59 to 24.74) (Harries 1969; Wong 1988). |
| Neuropathy due to vitamin E deficiency | This outcome was not measured. | |||||
| Retinopathy due to vitamin E deficiency | This outcome was not measured. | |||||
| BMI | This outcome was not measured. | |||||
| Height | This outcome was not measured. | |||||
| FEV1 % predicted: change from baseline | This outcome was not measured. | |||||
| *The basis for the assumed risk (e.g. the median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% CI) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). | ||||||
| GRADE Working Group grades of evidence | ||||||
| a. Downgraded once becasue of indirectness in the data. The single study reporting at 6 months included only children and therefore the effect on adults is unknown. b. Downgaded once due to imprecision resulting from small numbers of participants (n = 45). | ||||||
| Fat‐soluble vitamin E compared with control for cystic fibrosis | ||||||
| Patient or population: children and adults with cystic fibrosis Settings: outpatients Intervention: fat‐soluble vitamin E 10 mg/kg/day in 2 trials (Harries 1969; Wong 1988); participants < 20 kg = 600 IU/Day < 20 kg; participants > 20 kg = 1200 IU/day in 1 trial (Keljo 2000) Comparison: no supplementation (Harries 1969; Wong 1988) or placebo (Keljo 2000) | ||||||
| Outcomes | Illustrative comparative risks* (95% CI) | Relative effect | No of participants | Quality of the evidence | Comments | |
|---|---|---|---|---|---|---|
| Assumed risk | Corresponding risk | |||||
| No supplementation or placebo | Fat‐soluble oral vitamin E | |||||
| Vitamin E total lipid ratio | This outcome was not measured post‐intervention. | |||||
| Vitamin E levels in serum: umol/l Follow‐up: six months | None of the trials measured this outcome at the 6‐month time point. | 2 studies reported serum levels of vitamin E at 1 month and found a statistically significant result in favour of the supplemental group, MD 13.59 (95% CI 9.52 to 17.66) (Harries 1969; Wong 1988). 1 study reported serum levels of vitamin E at 3 months and found no statistically significant difference between intervention and control, MD 6.40 (95% CI ‐1.45 to 14.25) (Keljo 2000). | ||||
| Neuropathy due to vitamin E deficiency | This outcome was not measured. | |||||
| Retinopathy due to vitamin E deficiency | This outcome was not measured. | |||||
| BMI | This outcome was not measured. | |||||
| Height | This outcome was not measured. | |||||
| FEV1 % predicted: change from baseline | This outcome was not measured. | |||||
| *The basis for the assumed risk (e.g. the median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% CI) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). | ||||||
| GRADE Working Group grades of evidence | ||||||
| Outcome or subgroup title | No. of studies | No. of participants | Statistical method | Effect size |
| 1.1 Serum vitamin E levels Show forest plot | 3 | Mean Difference (IV, Fixed, 95% CI) | Subtotals only | |
| 1.1.1 Up to 1 month | 2 | 32 | Mean Difference (IV, Fixed, 95% CI) | 17.66 [10.59, 24.74] |
| 1.1.2 Up to 3 months | 1 | 45 | Mean Difference (IV, Fixed, 95% CI) | 11.61 [4.77, 18.45] |
| 1.1.3 Up to 6 months | 1 | 45 | Mean Difference (IV, Fixed, 95% CI) | 19.74 [13.48, 26.00] |
| 1.2 Weight Show forest plot | 1 | Mean Difference (IV, Random, 95% CI) | Totals not selected | |
| 1.2.1 Up to 3 months | 1 | Mean Difference (IV, Random, 95% CI) | Totals not selected | |
| 1.2.2 Up to 6 months | 1 | Mean Difference (IV, Random, 95% CI) | Totals not selected | |
| Outcome or subgroup title | No. of studies | No. of participants | Statistical method | Effect size |
| 2.1 Serum vitamin E levels Show forest plot | 3 | Mean Difference (IV, Fixed, 95% CI) | Subtotals only | |
| 2.1.1 Up to 1 month | 2 | 36 | Mean Difference (IV, Fixed, 95% CI) | 13.59 [9.52, 17.66] |
| 2.1.2 Up to 3 months | 1 | 36 | Mean Difference (IV, Fixed, 95% CI) | 6.40 [‐1.45, 14.25] |
