Take medications that block B12 absorption
The amount of time it takes for either treatment to take effect depends upon the severity of your B12 deficiency, and on the resulting health impacts of being deficient [4]
Additionally, if you have early Lebers disease or exhibit symptoms of low folate or iron levels like extreme fatigue, sore or red tongue, muscle weakness, and burning or prickling sensations in arms or legs, it's important to inform your doctor before using the nasal spray
But it could be helpful to screen people for B12 deficiency in advance and give them B12 supplements to delay or prevent the onset of depression
How do I adjust the vitamin B12 injection dosage for special conditions, such as renal impairment or malabsorption disorders
B12 injections are relatively pain free, you may experience a slight pinch of the skin