They fix nitrogen from dinitrogen (N2) in the air using the enzyme nitrogenase, in order to provide the cells in the filament with nitrogen for biosynthesis. Nitrogenase is inactivated by oxygen, so the heterocyst must create a microanaerobic environment.
Vitamin B12 is an especially important vitamin for maintaining healthy nerve cells, and it helps in the production of DNA and RNA, the body's genetic material. Vitamin B12 works closely with vitamin B9, also called folate or folic acid, to help make red blood cells and to help iron work better in the body.
General Intake Recommendations. Most women need 2.4 micrograms of vitamin B-12 each day to prevent a deficiency. However, pregnancy and breastfeeding increase your intake requirements -- pregnant women should consume 2.6 mcg of vitamin B-12 per day, while lactating women need 2.8 micrograms daily.enerally, you don't need to take vitamin B-12 supplements to maintain healthy B-12 levels, and a well-rounded diet provides all the vitamin B-12 you need. However, if you consult a doctor to take vitamin B-12 supplements, they can recommend a dose that will prevent B-12 deficiency.