What is Folic Acid (葉酸) ?

What is Folic acid?
Folic acid is know as Vitamin B9 or Bc, and named from the Latin word for "leaf".

Beneficial Folic acid or non-beneficial Folic acid?
Some scientists say that Folic acid is essential to numerous bodily functions such as synthesizing DNA, repairing DNA, and methylating DNA. Also it is very important in aiding rapid cell division and growth. In that point, Folic acid contributes to retaining the youth. But other scientists warn that high folic acid intake from supplement may actually promote some cancers as well as precancerous tumors and lesions.

Preventing Anemia
Children and Adults both require Folic acid to produce healthy red blood cells and prevent Anemia!

Which food contain Folic acid?
Leafy vegetables, such as spinach, asparagus, turnip greens
Legumes, such as dried or fresh beans, peas, and lentils
Egg yolks
Baker's yeast
Sunflower seeds
Liver
Kidney
Certain Fruits, orange juice, cantaloupe, honeydew melon, grapefruit, banana, raspberry, strawberry
Certain vegetables, beets, corn, tomato, broccoli, brussels sprouts, romaine lettuce, beer

The Character of the Folic acid.
Folic acid is susceptible to high heat and ultraviolet light, and is soluble in water ( so don't wash it away! ). It is heat-labile in acidic conditions and may also be subject to oxidation.

The compatibility of Folic acid
A number of drug interfere with the biosynthesis of Folic acid. Valproic acid, one of the most commonly prescribed anticonvulsants that is also used to treat certain psychological conditions, is a known inhibitor of folic acid.

The other benefits of Folic acid
1. possibly contributing heart disease and stroke
2. cancer
    Folate deficiency decreases intracellular S-adenosylmethionine (SAM), which inhibits cytosine methylation in  
    DNA, activates proto-oncogenes, induces malignant transformations, causes DNA precursor imbalances, 
    misincorporates uracil into DNA, and promotes chromosome breakage; all of these mechanisms increase the 
    risk of prostate cancer development.
    The association between folate and cancer appears to be complex and mixed.
3. Obesity
4. Depression
5. Memory and mental agility
6. Schizophrenia
   .....