• How do we evaluate a marginally low B12 level? 

    Cravens, David D.; Nashelsky, Joan (Family Physicians Inquiries Network, 2007-01)
    The best way to evaluate a low-normal B12 level is to check serum methylmalonic acid and homocysteine levels1 (strength of recommendation [SOR]: B, based on consistent level 2 or 3 studies). Give 1 or 2 mg of oral vitamin ...