Symptoms and Tests
Insufficient sources from a diet and “pernicious anemia” (the inability of the gut to absorb B12) can cause vitamin B12 deficiency. Excessive alcohol intake and medications (both OTC or prescriptions) can also cause a lack of B12, leading to symptoms such as:
Vitamin B12... With Benefits
Sources and Servings
Walsh, Steven, and IVU-SCI. “What Every Vegan Should Know about Vitamin B12.” The Vegan Society Oct. 2001, www.vegansociety.com/resources/nutrition-and-health/nutrients/vitamin-b12/what-every-vegan-should-know-about-vitamin-b12
Berkheiser, Kaitlyn.9 Health Benefits of Vitamin B12, Based on Science. Healthline, Healthline Media, 14 June 2018, www.healthline.com/nutrition/vitamin-b12-benefits.