A Vitamin B12 level of 140 pg/mL is considered low and may cause symptoms such as tiredness, weakness, numbness or tingling in the hands and feet, poor concentration, memory problems, dizziness, or low mood. Treatment usually involves Vitamin B12 Injection, commonly in the form of methylcobalamin or cyanocobalamin injections. In many cases, doctors advise 1000 mcg injections daily or on alternate days for about 1-2 weeks to quickly restore Vitamin B12 levels, followed by weekly injections for 4-6 weeks, and then monthly injections for maintenance if needed. The exact schedule can vary depending on the severity of the deficiency, symptoms, anaemia, nerve involvement, and the underlying cause of the deficiency. Some people may also improve with high-dose oral Vitamin B12 tablets after the initial injections. Along with treatment, it is important to identify the reason for the deficiency, which may include poor diet, stomach absorption problems, long-term acidity medicines, a vegetarian diet, or intestinal disorders. Eating foods rich in Vitamin B12, such as milk, curd, eggs, fish, chicken, and fortified cereals, may also help improve levels naturally. It is advisable to repeat the Vitamin B12 test and complete blood count after treatment to monitor improvement. Since dosage schedules may differ from person to person, you should take the injections under the guidance of a doctor to ensure safe and effective treatment.