Selenium Research
39 peer-reviewed studies · Evidence score: 9/10
Selenium supplementation for Hashimoto's thyroiditis: A Cochrane systematic review and meta-analysis
van Zuuren EJ et al. • Cochrane Database of Systematic Reviews (2019)
Moderate-certainty evidence supports selenium supplementation for reducing TPO antibody levels in Hashimoto's thyroiditis.
- Moderate-certainty evidence for TPO antibody reduction
- Inconsistent effects on thyroid hormone levels (TSH, T4, T3)
- Low-certainty evidence for quality of life improvements
Comparison of nutritional supplements in improving glycolipid metabolism and endocrine function in polycystic ovary syndrome: a systematic review and network meta-analysis
Hu X et al. • PeerJ (2023)
Carnitine was relatively effective in reducing body mass, while chromium, Omega-3, and selenium were beneficial for improving glucose metabolism.
- The network meta-analysis showed that carnitine, inositol, and probiotics reduced body weight and body mass index (BMI) compared to placebo, and carnitine outperformed the other supplements (SUCRAs: 96.04%, 97.73%, respectively).
- Omega-3 lowered fasting blood glucose (FBG) (SUCRAs: 93.53%), and chromium reduced fasting insulin (FINS) (SUCRAs: 72.90%); both were superior to placebo in improving insulin resistance index (HOMA-IR), and chromium was more effective than Omega-3 (SUCRAs: 79.99%).
- Selenium was potent in raising the quantitative insulin sensitivity index (QUICKI) (SUCRAs: 87.92%).
Healthy lifestyle choices: new insights into vitiligo management
Liang X et al. • Frontiers in immunology (2024)
Patients with vitiligo should reduce smoking and alcohol consumption and take appropriate vitamin E, B12, copper, and zinc supplements.
- Vitamin C [mean difference (MD), -0.342; 95% confidence interval (CI), -1.090-0.407; p >0.05), folic acid (MD, -1.463; 95% CI, -7.133-4.208; p >0.05), and selenium (MD, 0.350; 95% CI, -0.687-1.387; p >0.05) levels did not differ between the groups.
- The serum iron level of the vitiligo group was significantly higher than that of the control group (MD, 1.181; 95% CI, 0.390-1.972; p <0.005).
- Patients with vitiligo should reduce smoking and alcohol consumption and take appropriate vitamin E, B12, copper, and zinc supplements.
Selenium Supplementation in Patients with Hashimoto Thyroiditis: A Systematic Review and Meta-Analysis of Randomized Clinical Trials
Huwiler VV et al. • Thyroid : official journal of the American Thyroid Association (2024)
Indications for lowering TPOAb were found independent of THRT.
- We synthesized the results as standardized mean differences (SMD) or odds ratio (OR), assessed risk of bias using the Cochrane RoB 2 tool, and rated the evidence using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach.
- Our meta-analysis found that selenium supplementation decreased TSH in patients without THRT (SMD -0.21 [confidence interval, CI -0.43 to -0.02]; 7 cohorts, 869 participants; I2 = 0%).
- In addition, TPOAb (SMD -0.96 [CI -1.36 to -0.56]; 29 cohorts; 2358 participants; I2 = 90%) and malondialdehyde (MDA; SMD -1.16 [CI -2.29 to -0.02]; 3 cohorts; 248 participants; I2 = 85%) decreased in patients with and without THRT.
Selenium, antioxidants, cardiovascular disease, and all-cause mortality: a systematic review and meta-analysis of randomized controlled trials
Jenkins DJA et al. • The American journal of clinical nutrition (2020)
The addition of selenium should be considered for supplements containing antioxidant mixtures if they are to be associated with CVD and all-cause mortality risk reduction.
- However, a decreased risk with antioxidant mixtures was seen for CVD mortality when selenium was part of the mix (RR: 0.77; 95% CI: 0.62, 0.97; P = 0.02), with no association when selenium was absent.
- Similarly, when selenium was part of the antioxidant mixture, a decreased risk was seen for all-cause mortality (RR: 0.90; 95% CI: 0.82, 0.98; P = 0.02) as opposed to an increased risk when selenium was absent (RR: 1.09; 95% CI: 1.04, 1.13; P = 0.0002).
- The addition of selenium should be considered for supplements containing antioxidant mixtures if they are to be associated with CVD and all-cause mortality risk reduction.
Selenium for preventing cancer
Vinceti M et al. • The Cochrane database of systematic reviews (2018)
Well-designed and well-conducted RCTs have shown no beneficial effect of selenium supplements in reducing cancer risk (high certainty of evidence).
- For analyses of RCTs with low risk of bias, the summary risk ratio (RR) for any cancer incidence was 1.01 (95% confidence interval (CI) 0.93 to 1.10; 3 studies, 19,475 participants; high-certainty evidence).
- The RR for estimated cancer mortality was 1.02 (95% CI 0.80 to 1.30; 1 study, 17,444 participants).
- Selenium supplementation did not reduce overall cancer incidence (RR 0.99, 95% CI 0.86 to 1.14; 5 studies, 21,860 participants) nor mortality (RR 0.81, 95% CI 0.49 to 1.32; 2 studies, 18,698 participants).
Selenium and prostate cancer: systematic review and meta-analysis
Hurst R et al. • The American journal of clinical nutrition (2012)
The relation between selenium status and decreased prostate cancer risk was examined over a relatively narrow range of selenium status; further studies in low-selenium populations are required.
- Three high-quality studies included in the meta-analysis of toenail selenium and cancer risk indicated a reduction in prostate cancer risk (estimated RR: 0.29; 95% CI: 0.14, 0.61) with a toenail selenium concentration between 0.85 and 0.94 μg/g.
- The relation between selenium status and decreased prostate cancer risk was examined over a relatively narrow range of selenium status; further studies in low-selenium populations are required.
- Further research warranted to confirm findings
Selenium levels and skin diseases: systematic review and meta-analysis
Lv J et al. • Journal of trace elements in medicine and biology : organ of the Society for Minerals and Trace Elements (GMS) (2020)
Selenium levels were associated with several skin diseases and the disease severity, and high selenium levels tended to be a protective factor in certain skin diseases.
- Compared with controls, no significant difference in selenium was found in patients with vitiligo (SMD = 0.53, 95% CI: -0.40 to 1.45), alopecia areata (SMD = 0.47, 95% CI: -2.72 and 3.65), or eczema (SMD = 0.12, 95% CI: -0.24 to 0.48).
- A lower selenium level was found in patients with psoriasis (SMD = -0.62, 95% CI: -1.15 to -0.10), acne vulgaris (SMD = -1.02, 95% CI: -1.45 to -0.60), chloric acne (SMD = -2.35, 95% CI: -3.15 to -1.55), and atopic dermatitis (SMD = -2.62, 95% CI: -3.00 to -2.24).
- As for disease severity, severe patients had a higher selenium level than mild patients in psoriasis (SMD = 0.72, 95% CI: 0.07-1.38), but no difference was found in vitiligo (SMD = -0.26, 95% CI: -2.38 to 1.85) and alopecia areata (SMD = 0.46, 95% CI: -0.34 to 1.26).
Selenium and Preeclampsia: a Systematic Review and Meta-analysis
Xu M et al. • Biological trace element research (2016)
However, more prospective clinical trials are required to assess the association between selenium supplementation and preeclampsia and to determine the dose, beginning time, and duration of selenium supplementation.
- Using a random-effect model, a statistically significant difference in blood selenium concentration of -6.47 μg/l (95 % confidence interval (CI) -11.24 to -1.7, p = 0.008) was seen after comparing the mean difference of observational studies.
- Supplementation with selenium significantly reduces the incidence of preeclampsia.
- In randomized controlled trials, using a random-effect model, the relative risk for preeclampsia was 0.28 (0.09 to 0.84) for selenium supplementation (p = 0.02).
Selenium supplementation for management of gestational diabetes mellitus in pregnancy: a systematic review and meta-analysis of randomized controlled trials
Sun J et al. • BMC endocrine disorders (2025)
For pregnant women with gestational diabetes mellitus, daily supplementation with 200 µg of selenium may help lower fasting blood glucose levels and the risk of hyperbilirubinemia in the newborn, but it does not significantly affect total cholesterol, triglycerides, low density lipoprotein cholesterol, or high density lipoprotein cholesterol levels.
- Compared with placebo group, the selenium group did not significantly reduce the level of homeostasis model assessment of insulin resistance(P = 0.20, MD = -0.71, 95%CI: -1.80, 0.37).
- Selenium supplementation at 200 µg/d significantly reduced fasting plasma glucose(P = 0.0002, MD = -5.03, 95% CI: -7.70, -2.37) and the incidence of newborn's hyperbilirubinemia((P = 0.0003, MD = 0.09, 95% CI: 0.03, 0.33).
- Given the limitations of this study, these conclusions require further validation.
Selenium supplementation and thyroid disease: A systematic review and meta-analysis
Wichman J et al. • Thyroid (2016)
Selenium supplementation significantly reduced thyroid peroxidase antibody levels in Hashimoto's thyroiditis patients.
- Significant reduction in TPO antibody titers at 3 and 12 months
- Improved thyroid ultrasound echogenicity in some studies
- 200 mcg/day was the most commonly effective dose
Trace elements and Alzheimer dementia in population-based studies: A bibliometric and meta-analysis
Li K et al. • Environmental pollution (Barking, Essex : 1987) (2023)
All rights reserved.
- In a further meta-analysis, standardized mean differences (SMDs) of 13 elements were calculated to evaluate their altered in AD patients, including copper, iron, zinc, selenium, manganese, lead, aluminum, cadmium, chromium, arsenic, mercury, cobalt, and manganese.
- We identified four trace elements-copper (serum), iron (plasma), zinc (hair), and selenium (plasma)-altered in AD patients, with SMDs of 0.37 (95% confidence interval [CI]: 0.10, 0.65), -0.68 (95% CI: -1.34, -0.02), -0.35 (95% CI: -0.62, -0.08), and -0.61 (95% CI: -0.97, -0.25), respectively.
- Finally, we formed a database of various trace element levels in AD patients and healthy controls.
Zinc, copper, and selenium levels in vitiligo: a systematic review and meta-analysis
Anam K et al. • Scientific reports (2024)
This meta-analysis examined the effects of Copper.
- Publication bias was not found for the studies analysed.
- This study analyses the association of serum micronutrient levels and vitiligo among patients and controls from published research along with sub-group analysis specific to Asian populations using a meta-analysis.
- Low serum levels of Zinc and copper and high selenium levels are associated with Vitiligo.© 2024.
Selenium serum levels in patients with SARS-CoV-2 infection: a systematic review and meta-analysis
Roldán-Bretón NR et al. • Journal of nutritional science (2023)
More studies are needed to evaluate its impact on clinical severity through randomised clinical trials.© The Author(s) 2023.
- Meta-analysis was conducted to mean difference (MD) with a 95 % confidence interval (CI), and heterogeneity was tested by I2 with random factors with a MD between selenium levels, mortality, morbidity and healthy subjects with a P-value of 0⋅05.
- In conclusion, the patients with active SARS-CoV-2 infection had lower selenium levels than the healthy population.
- More studies are needed to evaluate its impact on clinical severity through randomised clinical trials.© The Author(s) 2023.
The effect of selenium therapy on mortality in patients with sepsis syndrome: a systematic review and meta-analysis of randomized controlled trials
Alhazzani W et al. • Critical care medicine (2013)
In patients with sepsis, selenium supplementation at doses higher than daily requirement may reduce mortality.
- Selenium supplementation in comparison to placebo was associated with lower mortality (odds ratio, 0.73; 95% CI, 0.54, 0.98; p = 0.03; I = 0%).
- Among patients receiving and not receiving selenium, there was no difference in ICU length of stay (mean difference, 2.03; 95% CI, -0.51, 4.56; p = 0.12; I = 0%) or nosocomial pneumonia (odds ratio, 0.83; 95% CI, 0.28, 2.49; p = 0.74; I = 56%).
- In patients with sepsis, selenium supplementation at doses higher than daily requirement may reduce mortality.
Effects of Probiotic and Selenium Co-supplementation on Lipid Profile and Glycemia Indices: A Systematic Review and Meta-analysis of Randomized Clinical Trials
Mohammadparast V et al. • Current nutrition reports (2023)
However, due to the small number of included studies, further trials are needed to confirm our findings.
- Meta-analysis examining Selenium efficacy
- Published in Current nutrition reports (2023)
- Further research warranted to confirm findings
The association between micronutrient levels and diabetic foot ulcer: A systematic review with meta-analysis
Kurian SJ et al. • Frontiers in endocrinology (2023)
This review provides evidence that micronutrient levels significantly differ in DFU patients, suggesting an association between micronutrient status and risk of DFU.
- DFU, compared to healthy controls (HC) had significantly lower vitamin D (MD: -10.82 14 ng/ml, 95% CI: -20.47, -1.16), magnesium (MD: -0.45 mg/dL, 95% CI: -0.78, -0.12) and selenium (MD: -0.33 µmol/L, 95% CI: -0.34, -0.32) levels.
- DFU, compared to DM patients without DFU, had significantly lower vitamin D (MD: -5.41 ng/ml, 95% CI: -8.06, -2.76), and magnesium (MD: -0.20 mg/dL, 95% CI: -0.25, -0.15) levels.
- The overall analysis showed lower levels of vitamin D [15.55ng/ml (95% CI:13.44, 17.65)], vitamin C [4.99µmol/L (95% CI:3.16, 6.83)], magnesium [1.53mg/dL (95% CI:1.28, 1.78)] and selenium [0.54µmol/L (95% CI:0.45, 0.64)].
Selenium and immune function: a systematic review and meta-analysis of experimental human studies
Filippini T et al. • The American journal of clinical nutrition (2023)
Although some of the data suggested beneficial effects of selenium supplementation on immune function, the overall picture appears to be inconsistent and heterogeneous due to differences in trial duration and interventions, plus evidence of null and even detrimental effects.
- Although some of the data suggested beneficial effects of selenium supplementation on immune function, the overall picture appears to be inconsistent and heterogeneous due to differences in trial duration and interventions, plus evidence of null and even detrimental effects.
- This trial was registered at PROSPERO (CRD42022312280).
- Further research warranted to confirm findings
Association of Selenium Levels with Neurodegenerative Disease: A Systemic Review and Meta-Analysis
Zhou J et al. • Nutrients (2023)
Generally, this meta-analysis indicated that AD patients are strongly associated with lower selenium concentrations compared with healthy people, which may provide a clinical reference in the future.
- A statistically significant relationship was only found for AD patients (SMD = -0.41, 95% CI (-0.64, -0.17), p < 0.001), especially for erythrocytes.
- Generally, this meta-analysis indicated that AD patients are strongly associated with lower selenium concentrations compared with healthy people, which may provide a clinical reference in the future.
- However, more studies are urgently needed for further study and treatment of neurodegenerative diseases.
The efficacy and safety of selenium supplementation versus placebo in the treatment of Graves' orbitopathy: A systematic review and meta-analysis of randomised controlled trials
Sharabati I et al. • Clinical endocrinology (2024)
Selenium is effective in reducing CAS and improving the palpebral aperture and GO-QOL in patients with GO.
- Similarly, it significantly improved these outcomes at 12 months.
- It also showed a significant decrease in the palpebral aperture at 6 months (MD = -1.49, 95% CI [-2.90, -0.08], p = .04).
- Selenium is effective in reducing CAS and improving the palpebral aperture and GO-QOL in patients with GO.