From the Research
Vitamin B12 testing is often ordered for patients with depression because a deficiency in this essential nutrient can cause or worsen depressive symptoms, and supplementation has been shown to improve treatment outcomes, as evidenced by a 2020 study published in Cureus 1. When a patient presents with depression, checking vitamin B12 levels helps rule out a potentially treatable contributing factor. B12 deficiency affects neurological function by impairing the production of neurotransmitters like serotonin and dopamine, which regulate mood. It also plays a crucial role in myelin formation and maintenance, which affects nerve signal transmission. Patients with B12 deficiency may experience depression, irritability, fatigue, and cognitive changes alongside the deficiency's other symptoms like numbness, tingling, and anemia. Some key points to consider include:
- Risk factors that make testing particularly important include older age, vegetarian or vegan diets, gastric bypass surgery, medications like metformin or proton pump inhibitors, and conditions affecting nutrient absorption such as Crohn's disease or celiac disease.
- A 2013 study published in The open neurology journal found that vitamin B12 supplementation significantly improved depressive symptoms in patients with low normal B12 levels 2.
- If deficiency is detected, supplementation (typically 1000 mcg daily initially) can improve both neurological symptoms and mood, potentially enhancing the effectiveness of antidepressant treatments, as suggested by a 2015 systematic review and meta-analysis published in International psychogeriatrics 3.
- The most recent and highest quality study, a 2020 review published in Cureus, highlights the importance of vitamin B12 supplementation in preventing the onset and improving the prognosis of depression 1.