Hi Dara, can you please provide a little more history so I can better guide you as fatigue can have many possible root causes. 

When did your symptom start? 
Do you eat a vegetarian or vegan diet? 
Are you taking an acid suppressing medication or diabetes medication like Metformin? 
What are your stress levels like (rate them 0-10)? 
When did you start the injections? What’s the dosage being given? 
Did you develop anxiety since taking them? 
Do you have any amalgam fillings in your mouth? 
If you have any labs, what is your MCV and MCH level on a CBC (complete blood count).
Did anyone measure MMA (methylmalonic acid) level for you along with B12? What was your serum B12 level, along with iron and ferritin?

Let’s start with these…

Hi Dara,

First of all: Welcome to the forum! 

Because it is difficult to get a complete picture of your unique situation, it is difficult to give personal advice via the forum.

That said, anemia can certainly be a cause of fatigue. The size or shape of the red blood cells makes it impossible to deliver oxygen efficiently. There are different types of anemia:
1. In macrocytic anemia, the red blood cells are too large, so they no longer fit into the thinnest capillaries. A B12 deficiency can be the cause, but vitamin B9 and/or B6 deficiency can cause the same dis-ease.
2. In microcytic anemia, the red blood cells are too small. The protein that transports oxygen is missing, called hemoglobin, which is highly dependent on the micronutrient iron.

Especially if people do not feel any relief after 1 or 2 months with B12 injections and the anemia persists, I recommend that the next step is to determine vitamins B9 and B6, iron, ferritin (the storage form of iron in the body) and haemoglobin at the doctor’s office.

Finally, fatigue can arise in many different ways. Throughout the course you will find different reasons. But here are some other common reasons for fatigue.
• Good sleep hygiene is critical (this is discussed in detail in the course material). 
• The vitamins have to be in the food to be absorbed. In a vegetarian diet nutrient deficiencies like B12 and iron can happen.
• You need good quality stomach acid to absorb minerals and vitamins like iron & vitamin B12. Stomach acid production can be influenced by several reasons like stress and bad eating hygiene. This is also discussed in detail in the course material.

Hopefully I gave you some tools to move forward!