Hello and thank you for the question.
Answers given are for informational purposes only and are not meant to replace an exam by an in-person.
I am Dr. Sohaib, a practicing Internal Medicine Specialist and i will do my best to help you today.
Normal values of B-12 are between 200 - 900 pg/mL (picograms per milliliter).
However the levels may vary from one laboratory to another (the reference ranges can be different).
Therefore the levels you have mentioned (350) are not considered to be low; however in various studies it has been observed that certain people may get the symptoms of B-12 deficiency when the levels are below 500. Therefore your doctor is the best person to decide whether you need this (low dose therapy for short duration) or not.
Moreover, B-12 is not the only cause for symptoms you have.
Folate deficiency, alcohol, hiv, thyroid disorders, diabetes and certain other metabloic disorders can also result in the same.
Your can ask your doctor for prescription drugs like pregabalin or gabapentin which are very helpful to control these kind of abnormal sensations you get.
There are certain over the counter preparations (like topical capsaicin) which when applied to the legs can also help control the sensations you get; while your doctor may continue to search for the exact underlying cause.
I would have been worried too if I were at your place, but let me reassure you that this is a treatable condition and carries a good prognosis with appropriate management.
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