Vitamin B12 deficiency: symptoms, causes, and risks

Vitamin B12, also known as cobalamin, is essential for the production of red blood cells, proper nervous system function, and DNA formation. A deficiency can lead to serious health complications, including anemia and permanent nerve damage if left untreated.

Common symptoms of deficiency include chronic fatigue, weakness, dizziness, shortness of breath, and pale or yellowish skin. Neurological and cognitive signs often include tingling sensations in the hands and feet, memory problems, difficulty concentrating, and mood changes such as irritability or depression.

Risk factors for deficiency include aging—as the body's ability to absorb the vitamin decreases after age 50—dietary choices like avoiding animal products, digestive issues such as gastritis, and the long-term use of certain acid-reducing medications. Pregnant and breastfeeding women are also at higher risk. Because symptoms often develop gradually, they are frequently mistaken for stress or general aging.