Primary Causes & Action Plans

Vitamin D

Critical for serotonin and dopamine synthesis; deficiency is common in mood disorders
Vitamin D is a neurohormone that regulates serotonin and dopamine production. Deficiency is present in up to 80% of people with depression, anxiety, and seasonal affective disorder.
Target > 50 ng/mL
Suggested Action Plan

If deficient, supplement vitamin D3 4000-5000 IU daily plus sun exposure. Target 60-80 ng/mL. Retest in 8-12 weeks. Most people notice mood improvement within 4-8 weeks.

Vitamin B12

Essential for monoamine neurotransmitter synthesis and methylation; deficiency causes mood disorder
B12 deficiency impairs monoamine synthesis and elevates homocysteine (which damages neurons). B12 deficiency causes depression, anxiety, and cognitive dysfunction and is easily corrected.
Target > 500 pg/mL
Suggested Action Plan

If low, supplement with methylcobalamin 1000-2000 mcg daily or 1000 mcg weekly injections. Most people notice mood improvement within 1-4 weeks.

Folate (B9)

Critical for methylation and monoamine synthesis; deficiency common in depression
Folate is required for serotonin and dopamine synthesis and for methylation reactions. Deficiency is associated with treatment-resistant depression. Supplementing folate improves antidepressant response.
Target > 8 ng/mL
Suggested Action Plan

If low, supplement with methylfolate (active form) 800-1000 mcg daily. Pair with B12 and B6 for optimal effect. Retest in 4-8 weeks.

Omega-3 Index

Ratio of omega-3 to omega-6 fatty acids; low ratio associated with depression and mood disorders
High omega-6 relative to omega-3 promotes systemic inflammation and neuroinflammation. Low omega-3 index is associated with depression. Increasing omega-3 intake improves mood.
Target > 8% of total fatty acids
Suggested Action Plan

Supplement with fish oil or algae oil providing 2000-3000 mg EPA/DHA daily. Eat fatty fish 2-3 times per week. Retest in 8-12 weeks. Mood often improves within 4-8 weeks.

Magnesium

Essential for nervous system relaxation and GABA synthesis; deficiency drives anxiety and depression
Magnesium deficiency prevents nervous system relaxation and GABA synthesis, driving anxiety and depression. Supplementation is one of the fastest-acting mood interventions.
Target > 2.0 mEq/L
Suggested Action Plan

Supplement with magnesium glycinate 300-500 mg daily. Most people notice mood improvement (reduced anxiety, improved sleep) within days to weeks.

Also in Brain & Mental Health

Adrenal Fatigue & HPA Axis Dysfunction Anxiety and Biomarkers Brain Fog Cognitive Decline Prevention

Explore by Biomarker

Vitamin D Guide
Depression Biomarkers
Magnesium Guide
Anxiety and Biomarkers
Vitamin B12 Guide
Homocysteine & Methylation

Getting Started

1
Test Nutrient Status Before Medication

Order vitamin D, B12, folate, B6, omega-3 index, and magnesium. Many people with diagnosed mood disorders have multiple nutrient deficiencies that fully explain their symptoms.

2
Start with Magnesium

Magnesium is often the most deficient and produces the fastest mood improvement. Magnesium glycinate 300-500 mg at bedtime often produces noticeable mood improvement within days.

3
Replete All Deficient Nutrients Simultaneously

Do not fix one nutrient and ignore others. If vitamin D, B12, and magnesium are all low, supplement all three. Nutritional synergy produces better results than piecemeal supplementation.

4
Improve Your Diet Simultaneously

Increase omega-3 rich foods: fatty fish, walnuts, flaxseeds, chia seeds. Reduce omega-6 rich seed oils. Increase B-vitamin rich foods: leafy greens, legumes, eggs. Food + supplements work synergistically.

5
Retest and Reassess at 8-12 Weeks

Mood should improve measurably within 8-12 weeks of nutrient repletion. Retest biomarkers to confirm improvement. If mood is not improving, consider whether psychiatric medication is needed as adjunctive therapy.

Why I built this guide.

"Many mood disorders are symptoms of nutrient deficiency. Test and correct the deficiency. Mood often improves rapidly."

Explore More

Get a Discount

Save $25 with our verified Function Health promo codes

Read Our Review

Our data-driven review of Function Health covering 14 insurers

Is It Worth It?

We analyzed costs across 42 states to answer this question

Compare All Insurers

See how every major insurer compares to Function Health