The Vitamin B12 test measures the amount of Vitamin B12 in your blood, which is essential for nerve function, red blood cell production, and DNA synthesis. A deficiency can lead to symptoms like fatigue, weakness, memory issues, numbness, or mood disturbances, while high levels might indicate liver disorders or certain health conditions. The normal range of Vitamin B12 varies based on age and health status. This test helps diagnose deficiencies, anemia, and neurological issues. Learn about the Vitamin B12 test procedure, normal range, causes of low or high levels, deficiency symptoms, and the cost of the test in India. Get insights to interpret your results and know when to consult a doctor.