Older adults As you age, your ability to absorb vitamin B12 decreases and your appetite declines, making it difficult for some people to get enough B12 through diet alone
[19] Cyanocobalamin vials should be stored at controlled room temperature (15 - 25 C), protected from excessive light and humidity, and kept in their original packaging to preserve potency
Amounts of vitamin B 12 that are recommended by the Food and Nutrition Board, National Academy of Science-National Research Council for pregnant women (4 mcg daily) should be consumed during pregnancy
The 28-day use window applies only to refrigerated storage
In this case, the B12 shots have started to heal the damaged neurons myelin sheath, but the neural network in which the healed neuron is in, is in a super sensitive state (with extra receptors), so the patient may feel pain or other unpleasant sensations
This can contribute to fatigue, weakness, light-headedness, and difficulty concentrating