However, if youre already getting enough of the vitamin from your diet, its unlikely that youll notice any changes to your energy levels by taking a vitamin B12 supplement
This guarantees 100% bioavailability
The Bigger Concern: Leaving a Deficiency Untreated When weighing the minimal risks of B12 injections, it helps to consider the well-documented risks of an untreated B12 deficiency
Heavy training can increase nutritional demands
For severe deficiencies, it can take even longer, since your vitamin stores are extremely depleted
Folic Acid, vitamin B9 is not a substitute for cyanocobalamin, vitamin B12 deficiency, although it may improve vitamin B12 megaloblastic anemia