Yes 396 is too low.
Under 500 should be considered deficient. You want to be closer to 1,000.
Are you taking B12 supplements?
You can try B12 Methylcobalamin sublinguals or spray to raise levels. Stay away from Cyanocobalamin, it's a cheaper version in most vitamins and not good.
Methylcobalamin and Adenosylcobalamin taken together are supposed to be helpful.
I was told this:
oral B12 using a mix of both methylcobalamin (MeCbl) and adenosylcobalamin (AdCbl) resolves the problem for most people.
It's important however to address the underlying reason why the gut bacteria are not creating new B12 and that requires rebuilding the gut microbiome while totally avoiding all sources of antibiotics.
Go for 1,000-2,000mcg daily to raise levels. Don't take with Vitamin C, it blocks B12 absorption.
Even with sufficient intrinsic factor and good intestinal health, B-12 is very poorly absorbed. For example, about 10 micrograms of a 500-microgram oral supplement -- only 2 percent -- is typically absorbed in healthy people, according to the National Institutes of Health.
Approx. Absorbability of B12 sublinguals:
500mcg = 10mcg absorbed
1,000mcg = 20mcg absorbed
2,000mcg = 40mcg absorbed
Do you have symptoms?
How are your Vitamin D levels?
I forgot to add that B12 deficiency causes anxiety, depression, balance issues, tingling in extremities, fatigue...
If you raise your vitamin levels you can get rid of the anxiety. I wanted to jump out of my skin in September. While I'm still recovering, things are manageable now. People had suggested I take anti depressants because I was upset, but I kept telling them it's because my body is sick.
I have tinnitus, milder anxiety and internal tremors and continue with B12 to get rid of these symptoms.
I was diagnosed with anemia and Vitamin D deficiency. My B12 wasn't tested. It took awhile to find out it's pretty common to also be D deficient along with B12. I raised my D levels and got iron up but still had symptoms. That's when I added more B12.
You need to make sure to add more potassium and sodium when taking more B12. They need to be balanced. I drink coconut water for potassium and eat potassium rich foods. I use Celtic grey salt for sodium. It has trace minerals and 3 types of magnesium.
If you add some magnesium to your routine it can help with your anxiety also. I find Magnesium Malate helpful. Avoid Magnesium Oxide it has poor absorption and really only good for laxative affect. You can also buy topical magnesium (Magnesium Oil/Magnesium Spray). Very helpful on your feet at night. If it stings, you can dilute with more water. It's never stung on my feet, but has on the back of my knees and neck.