B12 381

Since I gave birth six months ago by c-section I've had strange symptoms. I have bad back pain that won't go away, tingling in my legs as if they are alseep, and electric shocks that go up my back to my neck everytime I walk. I also noticed my hair turning grey. Everyone keeps telling me I'm still recovering from birth. My mom then just found out she has a b12 deficiency at level 150, so she suggested I get tested for that. I did and it came back at 381 and my doctor listed that as normal. My moms doctor said levels 200-400 can still cause symptoms. Do you think a 381 could cause these symptoms? I'm not sure what to do. I was just thinking about it, my mom is 20 years older than me. So if my levels are this low now, what if they keep dropping, where will I be 20 years from now. If someone could give me an answer that would be helpful. Thanks.