I had trouble sleeping for some days and 10 days back got extreme anxiety and panic attack and difficulty breathing all of a sudden. I did a full body checkup and found b12 level at 148(recomended is 200-900) and Vit D at 28. Haemoglobin was 14.8. Since the day i got this panic attack, having extreme fatigue, weekness, yawning, tingling, difficulty concentrating and heavy breathing at times and poor walking coordination at times. I feel sleeping throughout the day but at night it gets difficult to sleep. I have taken 4 shots of Eldervit injection IM and have only got slight relief. Doctor recommended to take nurokind lc tablet once after 5 injection for 45 days. Since i have not got much relief, would like to know how much time it usually takes before i feel better. Even after injection does the body take time to respond and recover.