You may see do-it-yourself (DIY) B12 test kits for sale online, but there are many reasons to skip these, says Ren
Doctors want to keep blood levels of B12 within range because of an imaginary fear of overdose
The AAFPs evidence-based clinical review states directly: Oral administration of high-dose vitamin B12 (1 to 2 mg daily) is as effective as intramuscular administration for correcting anemia and neurologic symptoms in patients with B12 deficiency (Langan RC, Goodbred AJ, American Family Physician, 2017)
Even if stress is your primary trigger, your skin may still react to other things like heat, spicy foods, alcohol, or vigorous exercise
Various types of treatments will include measured dosages every week or a few may include higher doses of Vitamin B12 per month
Evidence boundary The published trial record describes safety more clearly than efficacy