Can low selenium levels cause anxiety?

Low Selenium and Anxiety: The Connection

Low selenium levels can contribute to anxiety, particularly in individuals with significant deficiency, as evidenced by multiple studies showing associations between selenium status and mood disorders. 1

Selenium Deficiency and Mental Health

Selenium is an essential trace element with important functions in the brain that differ from other organs. During times of deficiency, the brain preferentially retains selenium, suggesting its critical role in neurological function 2. The relationship between selenium and mental health has been established through several key findings:

• A 2022 study found that children with lower serum selenium concentrations were more likely to meet clinical cutoffs for total anxiety, panic/somatic disorder, generalized anxiety disorder, social anxiety disorder, and school phobia 1
• Multiple studies have reported that low selenium intake is associated with poorer mood, including increased anxiety and depression 2, 3
• Selenium supplementation has been shown to improve mood, particularly decreasing anxiety, in individuals with low baseline selenium levels 3

Diagnosis of Selenium Deficiency

To determine if anxiety might be related to selenium deficiency, consider:

• Laboratory assessment: Plasma selenium levels <0.4 μmol/L (<32 μg/L) indicate definite deficiency requiring immediate supplementation 4
• Inflammatory markers: Measure CRP simultaneously with selenium, as inflammation significantly affects selenium levels (CRP 10-40 mg/L can reduce plasma selenium by 15-25%) 4
• Functional markers: Reduced glutathione peroxidase activity in plasma and red blood cells is a marker of selenium deficiency 4

Risk Factors for Selenium Deficiency

Be alert for selenium deficiency in patients with:

• Long-term parenteral nutrition without selenium supplementation 4
• History of bariatric surgery, especially malabsorptive procedures 4
• Prolonged enteral nutrition with products low in selenium 4
• Severe burns or continuous renal replacement therapy (increased losses) 4
• Residence in selenium-deficient geographical regions 4

Clinical Manifestations

Beyond anxiety, selenium deficiency may present with:

• Muscle weakness and pain 4
• Cardiac arrhythmias 4
• Increased susceptibility to viral infections 4
• Poor wound healing 4
• Erythrocyte macrocytosis and anemia 4
• Glossitis and taste changes 4
• Skin/hair changes including depigmentation 4

Treatment Approach

For patients with anxiety potentially related to selenium deficiency:

1. Confirm deficiency: Measure plasma selenium and CRP simultaneously
2. Supplementation:
   • For mild deficiency: 100 μg/day of selenium orally is appropriate 3
   • For severe deficiency (plasma selenium <0.4 μmol/L): Consider IV route for rapid correction with up to 400 μg/day for 7-10 days 5
3. Monitor response: Recheck selenium levels after supplementation

Important Considerations

• The response to selenium supplementation for mood improvement has been observed with doses greater than those needed to produce maximal activity of selenoprotein glutathione peroxidase 2
• The form of selenium supplement matters - sodium selenite may not be the optimal form for treating anxiety/depression symptoms 6
• Individuals with lower baseline selenium status tend to show greater mood improvements with supplementation 7

Pitfalls to Avoid

• Failing to measure CRP alongside selenium can lead to misinterpretation of selenium status 4
• Not considering geographical variations in selenium reference ranges can lead to misdiagnosis 4
• Overlooking selenium supplementation in patients on long-term parenteral or enteral nutrition 4
• Assuming all forms of selenium supplementation are equally effective for mental health symptoms 6

While selenium deficiency can contribute to anxiety, it's important to recognize that anxiety is multifactorial, and addressing selenium status is just one potential intervention for improving symptoms in deficient individuals.