Vitamin Deficiencies and Depression: Medical Evidence Linking Nutritional Gaps to Mental Health
- The Simple Routine
- Nov 7, 2025
- 2 min read
Recent research has increasingly highlighted the connection between vitamin deficiencies—especially vitamin D—and the risk of depression. While causality remains complex, multiple studies provide compelling evidence that low levels of key nutrients may contribute to depressive symptoms.
The Link Between Vitamin D and Depression
A 2025 review published in Biomolecules and Biomedicine synthesized 66 observational studies across 31 countries. It found that low blood levels of 25-hydroxy-vitamin D [25(OH)D]—particularly below 30 nmol/L—were consistently associated with higher rates of depression in adults.
Although the review emphasized that correlation does not prove causation, the consistency across diverse populations suggests a strong biological relationship.
Biological Mechanisms Behind the Link
Vitamin D plays a role in regulating serotonin, a neurotransmitter critical for mood stabilization.
It also influences inflammatory pathways and neuroplasticity, both of which are implicated in depression.
Deficiencies may impair brain function and increase vulnerability to mood disorders.
Late-Life Depression and Nutrient Deficiency
A 2025 review in Frontiers in Nutrition focused on older adults and found that deficiencies in vitamins B12, B6, and folate were also linked to increased depression risk.
These vitamins are essential for homocysteine metabolism and neurotransmitter synthesis, and their absence may exacerbate cognitive decline and mood disorders.
Vitamin Deficiencies and Depression: Medical Evidence Linking Nutritional Gaps to Mental Health
Recent studies have revealed a strong connection between vitamin deficiencies—especially vitamin D, B12, B6, and folate—and increased risk of depression. These nutrients play critical roles in brain function, neurotransmitter regulation, and inflammation control.
Medical Evidence
A 2025 review in Biomolecules and Biomedicine analyzed 66 studies across 31 countries.
Found consistent association between low vitamin D levels (below 30 nmol/L) and higher depression rates.
A 2025 review in Frontiers in Nutrition linked deficiencies in B12, B6, and folate to late-life depression.
Biological Mechanisms
Vitamin D regulates serotonin and reduces inflammation.
B vitamins support neurotransmitter synthesis and homocysteine metabolism.
Deficiencies impair neuroplasticity and cognitive function.
Low vitamin D is consistently associated with depression.
B12, B6, and folate deficiencies increase risk of mood disorders, especially in older adults.
These vitamins are essential for brain health and emotional regulation.
Supplementation may help improve symptoms, but should be guided by medical professionals.
