Dietary Supplements

Impact of organic selenium supplementation on glycaemic control and quality of life in patients with diabetic neuropathy: a randomized placebo-controlled trial.

Bahari P, Mobasseri M, et al. • European journal of nutrition • 2026

PubMed 42631762 DOI 10.1007/s00394-026-04091-8

TL;DR

Eight weeks of organic selenium supplementation (200 μg/day) significantly improved glycemic indices and insulin sensitivity in patients with T2DM and diabetic peripheral neuropathy, without notable adverse effects.

Key Findings

Results

Selenium supplementation significantly reduced fasting blood sugar (FBS) compared to placebo.

Adjusted mean difference (aMD) of -33.95 mg/dL (95% CI: -64.2 to -5.5); p=0.021
Dose: 200 μg/day of organic selenium as selenium-enriched yeast for 8 weeks
50 patients with T2DM and confirmed diabetic peripheral neuropathy were randomized
Analysis conducted using ANCOVA, adjusting for baseline FBS, age, sex, BMI, and MNSI score

Results

Selenium supplementation significantly reduced HbA1c compared to placebo.

aMD of -1.20% (95% CI: -1.79 to -0.61); p<0.001
The authors note this approximately 1.2% reduction in HbA1c 'may be clinically meaningful'
The intervention lasted 8 weeks in a triple-blind, randomized, placebo-controlled design
Authors caution findings should be interpreted cautiously given the modest sample size, short follow-up, and single-centre design

Results

Selenium supplementation significantly reduced HOMA-IR (a measure of insulin resistance) compared to placebo.

aMD of -1.57 (95% CI: -3.06 to -0.08); p=0.039
HOMA-IR is a calculated index reflecting insulin resistance
50 participants were enrolled (25 per group) with confirmed DPN

Results

Selenium supplementation significantly increased QUICKI (a measure of insulin sensitivity) compared to placebo.

aMD of 0.02 (95% CI: 0.003 to 0.034); p=0.018
QUICKI (Quantitative Insulin Sensitivity Check Index) increases indicate improved insulin sensitivity
This finding is consistent with the HOMA-IR reduction observed in the same study

Results

Improvements in quality of life (WHOQOL-BREF) and overall sleep quality within the selenium group did not reach statistical significance in between-group analyses.

WHOQOL-BREF and PSQI (Pittsburgh Sleep Quality Index) improvements were observed within the selenium group but not statistically significant between groups
The exception was daytime dysfunction of sleep quality, which did reach significance: aMD of -0.54 (95% CI: -1.05 to -0.03); p=0.039
These were prespecified secondary outcomes of the trial

Results

Adverse events were minimal and comparable across selenium and placebo groups.

No notable adverse effects were reported with 200 μg/day organic selenium over 8 weeks
The trial received ethics approval (IR.TBZMED.REC.1401.374) and was registered (IRCT20131009014957N10)
The trial was triple-blind in design

Methods

The study population consisted of patients with both T2DM and confirmed diabetic peripheral neuropathy (DPN), a population not well-represented in prior selenium research.

50 patients were randomized in a single-centre, triple-blind, placebo-controlled trial
Intervention: 200 μg/day selenium-enriched yeast vs. placebo for 8 weeks
Primary outcomes were FBS, HbA1c, HOMA-IR, and QUICKI; secondary outcomes included WHOQOL-BREF and PSQI
The authors note that prior evidence on selenium in T2DM management 'remains inconsistent, particularly in patients with DPN'

What This Means

This research suggests that taking a daily supplement of organic selenium (200 micrograms, derived from selenium-enriched yeast) for 8 weeks can meaningfully improve blood sugar control and insulin sensitivity in people who have type 2 diabetes complicated by nerve damage (diabetic peripheral neuropathy). Specifically, the study found significant reductions in fasting blood sugar, HbA1c (a marker of average blood sugar over roughly 3 months), and a measure of insulin resistance, alongside improvements in insulin sensitivity — all compared to a placebo group. The roughly 1.2% drop in HbA1c observed is a magnitude that has been considered clinically relevant in diabetes management. The study also looked at quality of life and sleep quality, and while participants taking selenium showed improvements in these areas, most of those differences were not statistically significant compared to the placebo group. One exception was daytime dysfunction related to sleep, which did improve significantly with selenium. Adverse effects were minimal and similar between the two groups, suggesting the supplement was well-tolerated over this short period. This research matters because many people with type 2 diabetes struggle to maintain adequate blood sugar control even with standard medications, and complications like nerve damage can worsen their quality of life. However, the study was small (50 participants), short (8 weeks), and conducted at a single center, so the results should be viewed as preliminary. Larger, longer studies are needed before drawing firm conclusions about selenium as a routine add-on treatment for this population.

Check Your Own Numbers

Upload your bloodwork. We'll cross-reference your results against this study and 4,700 others.

Upload Your Labs

Have a question about this study?

Citation

Bahari P, Mobasseri M, Ranjbari S, Asadi E, Shojaie-Dizaji L, Khakpaki A, et al.. (2026). Impact of organic selenium supplementation on glycaemic control and quality of life in patients with diabetic neuropathy: a randomized placebo-controlled trial.. European journal of nutrition. https://doi.org/10.1007/s00394-026-04091-8

Key Findings

What This Means

Check Your Own Numbers

Have a question about this study?

Related Research

Citation