Doctors do recommend a B12 test to evaluate B 12 deficiency
Both are equally bad. The symptoms of folic acid deficiency are lethargy, breathelessness, fatigue and headaches. Get a test done to know if you have anemia.
It depends whether you are having specifically B12 deficiency or any other disease. If you are having B12 deficiency then you are recommended to take B12.
You are recommended to check with a doctor. You can either take cynocobalmin tablets or hydroxocobalamin injections to boost your vitamin B12 levels. In addition take a protein rich diet comprising of dairy, poultry and meat to increase your B12 and iron naturally.
Deficiency of vitamin B12 is associated with anemia. One treats it by consuming dairy products and supplements which are rich in Vitamin B12.