Serum vitamin E levels and chronic inflammatory skin diseases: A systematic review and meta-analysis.

PloS one. 2021;16(12):e0261259

Plain language summary

Vitiligo, Psoriasis, Acne and Atopic Dermatitis are chronic immune-mediated inflammatory skin conditions characterised by itchy skin. In previous studies, decreased serum vitamin E levels have been associated with an increased risk of skin diseases. Nuts, oils from plants, and vegetables contain vitamin E, which is a dietary bioactive compound that has anti-inflammatory and antioxidant properties. In this systematic review and meta-analysis, twenty case-controlled studies were included, of which thirteen specifically examined alpha-tocopherol levels. Psoriasis, Vitiligo, atopic dermatitis, and acne patient groups had significantly lower levels of serum Vitamin E than the control groups. There is no clear understanding of the pathogenesis of chronic inflammatory skin conditions. One of the underlying mechanisms is the interaction between oxidative stress and the immune system, as well as the accumulation of free radicals in the epidermal layers of the skin. As there is limited evidence regarding the benefits of Vitamin E in improving chronic inflammatory skin conditions, further robust studies are necessary. Healthcare professionals can use this research to gain a better understanding of the potential clinical applications of vitamin E in the treatment of skin disorders.

Expert Review


Conflicts of interest: None

Take Home Message:
  • Low serum vitamin E levels are reported to be associated with several chronic inflammatory skin diseases, such as vitiligo, psoriasis, atopic dermatitis, and acne.
  • Practitioners could consider vitamin E therapy in those with low serum concentrations

Evidence Category:
  • X A: Meta-analyses, position-stands, randomized-controlled trials (RCTs)
  • B: Systematic reviews including RCTs of limited number
  • C: Non-randomized trials, observational studies, narrative reviews
  • D: Case-reports, evidence-based clinical findings
  • E: Opinion piece, other

Summary Review:
This systematic review and meta-analysis report on the association between serum vitamin E levels and chronic inflammatory skin diseases.

The review which followed PRISMA reporting guidelines, screened 892 studies. After the selection and exclusions, 20 case-control studies were included involving a total of 1172 patients.

The studies that were included focused mainly on chronic inflammatory diseases, including vitiligo, psoriasis, atopic dermatitis, and acne. Eight studies included only adults, five included only children or teenagers and six studies included adults and children. One study had no age description.

Thirteen studies stated that alpha-tocopherol was used in their investigations. However, seven studies did not describe the subunit of vitamin E.

Primary clinical outcomes were:

  • Seven studies, with 351 cases and 350 controls reported that compared with the control group, vitiligo patients had lower serum vitamin E concentrations (Standard Mean Difference (SMD):0.70, 95% Cl:121-0.19.
  • Six studies investigated the change of serum vitamin E levels in patients with psoriasis, with 278 cases and 257 controls. Compared with the control group, psoriasis patients had lower serum vitamin E concentrations (SMD: -2.37, 95% CI: -3.57 to -1.18).
  • The serum vitamin E Levels in patients with atopic dermatitis were observed in 4 studies, with 259 cases and 307 controls. Compared with the control group atopic dermatitis patients had lower serum vitamin E concentrations (SMD: -1.08, 95% CI: -1.80 to -0.36).

Levels of serum vitamin E in acne patients were reported in 3 studies, with 284 cases and 186 controls. Compared with the control group, acne patients had lower serum concentration levels of vitamin E (SMD: -0.67, 95% CI: -1.05 to -0.30).

No publication bias was found in any association (Egger’s test >0.05), though heterogeneity was considerable in every case (I2 > 80%), though this interaction was not significant for acne (p=0.879). Associations were not split by age, or any other cofactor, however sensitivity analyses did not indicate modification of the results.

The authors also assessed the association between skin disease severity and serum vitamin E concentrations. Overall, more severe disease was associated with a lower serum vitamin E concentration (SMD -1.56, 95% CI:-2.53 to -059).

Clinical practice applications:
  • Vitamin E has gained the attention of researchers as a potential adjuvant therapy for various skin disorders due to its excellent antioxidant and anti-inflammatory properties.
  • This review reports on the low levels of serum vitamin E found in patients with vitiligo, psoriasis, atopic dermatitis, and acne, and also suggests that serum concentrations of vitamin E are lower in those with more severe disease. Based on these findings, practitioners could therefore consider investigating the serum vitamin E levels of patients with inflammatory skin diseases and consider including vitamin E in their treatment protocols if their serum vitamin E levels are low.

Considerations for future research:
  • The small number of studies in this review indicates the need for further research to be done on vitamin E and inflammatory skin diseases.
  • Although there are reports on the antioxidant and anti-inflammatory properties of vitamin E, further investigations are needed to determine the exact mechanism of action in inflammatory skin diseases.
  • Additionally, further investigation is needed to evaluate which chemical forms of vitamin E and their dosage amounts have beneficial effects on inflammatory skin diseases.

Abstract

BACKGROUND Vitamin E has long been linked to skin health, including all of its possible functions in cosmetic products, to its roles in membrane integrity and even the aging process. However, reports on the relationship between serum vitamin E levels and the risk of chronic inflammatory skin diseases have been inconsistent. We performed a systematic review and meta-analysis to evaluate the association between serum vitamin E levels and chronic inflammatory skin diseases. METHODS We searched the PubMed, Web of Science and Scopus databases, with no time limit up to 30.06.2021. Studies examining serum vitamin E levels in patients with chronic inflammatory skin diseases were selected. RESULTS Twenty articles met the inclusion criteria. Compared with controls, a lower vitamin E level was found in patients with vitiligo (SMD: -0.70, 95% CI: -1.21 to -0.19), psoriasis (SMD: -2.73, 95% CI: -3.57 to -1.18), atopic dermatitis (SMD: -1.08, 95% CI: -1.80 to -0.36) and acne (SMD: -0.67, 95% CI: -1.05 to -0.30). CONCLUSIONS Our meta-analysis showed that serum vitamin E levels were lower in patients suffering from vitiligo, psoriasis, atopic dermatitis and acne. This study highlights the need to evaluate vitamin E status to improve its level in patients with skin diseases.

Lifestyle medicine

Fundamental Clinical Imbalances : Immune and inflammation ; Structural
Patient Centred Factors : Mediators/Vitamin E
Environmental Inputs : Diet ; Nutrients
Personal Lifestyle Factors : Nutrition ; Environment
Functional Laboratory Testing : Blood
Bioactive Substances : Alpha-tocopherol ; Vitamin E

Methodological quality

Jadad score : Not applicable
Allocation concealment : Not applicable

Metadata