Hosit Tablet contains Mecobalamin (vitamin B12), Pyridoxine (vitamin B6) and folic acid (vitamin B9), which are usually safe and commonly used to treat nerve-related symptoms caused by deficiency. A vitamin B12 level above 800 is generally not harmful and does not usually cause tingling or burning sensations. In most cases, Hosit Tablet itself is not the cause of these symptoms when taken in the recommended doses. Burning or tingling in the fingers and toes is more commonly due to nerve irritation or neuropathy. This can happen even after correcting B12 levels, especially if nerves were affected earlier. Other possible causes include vitamin B6 imbalance, neck-related nerve compression, or early changes in the spine. The mild neck pain you are experiencing may also point towards a nerve or muscle-related issue. Since your blood sugar and blood pressure are well controlled, major metabolic causes are less likely. It is best to discuss this with your doctor for proper assessment and further evaluation if needed.