V i t a m i n B 9
Vitamin B9' s (Folic Acid or Folate) most important role is in cellular replication, it functions as a coenzyme during the synthesis of genetic material (DNA). Also crucial for proper brain function and playing an important role in mental and emotional health.
The human body needs folic acid to synthesize DNA and repair DNA, the genetic material, especially important for rapid and precise cell division and growth.
The role of Vitamin B9 during cellular reproduction is also important during the formation of both red and white blood cells. Vitamin B9 plays a pivotal role in ensuring that adequate amounts of functioning red blood cells are found in the blood stream.
Folic acid works closely with vitamin B12 to help make red blood cells, and helps iron to work properly in the body.
There is a complex interaction between folic acid, vitamin B12 and iron. A deficiency of one may be masked by excess of another so the three must be in balance.
Vitamin B9 also has a few other functions inside the body including an use in fat metabolism as well as bile production in the liver. It also plays a part in metabolizing proteins. It works in conjunction with vitamin B12 and vitamin C to help in the digestion and use of proteins, and to help produce new protein when required.
Folate helps to increase the appetite, if necessary, and also stimulates the creation of stomach acids for proper digestion. It also helps to maintain liver health.
Leafy vegetables are principal sources of folic acid. A complete lack of dietary folate takes months before deficiency develops as normal individuals have about 500 – 20,000 µg of folate in body stores.
Folic acid may also reduce chromosomal defects in sperm. A good benefit is indicated even for more than 700 µg folate per day eventhough 1.8 times the recommended dietary allowance. Folate is necessary for fertility in both men and women.
Important to mention its absolute vital role in fetal development. Vitamin B9 is used in large amounts by a fetus because of how fast the fetal cells are dividing. A pregnant women, for the benefit of the unborn, should consider to take Folic Acid supplements.
400 µg RDA - 1000 µg UL
RDA (recommanded dietary allowances) per day 
UL (upper intake level) per day 
 Dietary Reference Intakes: Vitamins.
The National Academies, 2001