Structural Biochemistry/Folic acid
Folic acid is one of the B-complex vitamins required in order to produce red blood cells. Folic acid is a manufactured form of folate; folate can be found naturally in certain foods, such as leafy green vegetables, nuts, beans, and grains. Some cereals contain 100% of the daily value of folic acid a woman should take per day. If there is an insufficient amount of this vitamin, it can cause anemia. Because the body does not make much folic acid, it is useful to take a vitamin pill form to ensure that you get the recommended daily value.
Many scientists around the 1920s thought that folate deficiency and anemia were the same condition. In the year 1931, a researcher named Lucy Wills led to determining folate as the nutrient needed to prevent anemia during pregnancy. In other words, folate was an important source needed during the state when a person is pregnant. Through this identification, Dr. Wills illustrated that anemia could be reversed with brewer's yeast. Thus, folate was seen as the corrective substance in brewer's yeast. In the year 1941, Mitchell and other people first separated and extracted folate from spinach leaves.
Furthermore, in 1943, Bob Stokstad who worked at the Lederle Laboratories of the American Cyanamid Company, isolated the pure crystalline form and was then able to determine folate chemical structure. Under the supervision and help of Director of Research Dr. Yellapragada Subbarao, a group called "folic acid boys" in the year 1945 was able to obtain folic acid in a pure crystalline form. This historical research project led to the synthesis of the antifolate aminopterin. Antifolate aminopterin is the first anticancer drug.
Then in the 1950s to the 1960s, many scientists started to study biochemical mechanisms and discovered the different actions for folate. This led to linking folate deficiency to neural tube defects. Overall, many US scientists noticed that food sold in markets contain really little folate; therefore, more food should contains folate to help people especailly those who are pregnant.
Foods Containing Folate
There are many healthy foods that are very high in folate. Some are listed below:
- Egg yolks
- Sunflower seeds
- Liver and Kidney Products
- Leafy vegetables such as turnip greens, lettuce, spinach
- Legumes such as beans, peas, and lentils
- Grain Products such pasta, cereal, bread
Food that contains few amount in folate:
- Fruits such as banana, raspberry, strawberry
- Juice such as orange or pineapple juice
Note that folate is naturally found in foods that are susceptible in high heat and UV light. Folate is also water soluble.
Folic Acid and Pregnancy
Folic acid has been proven to protect against birth defects during the first weeks of pregnancy. Such birth defects include spina bifida, which is the case involving the backbone and spinal canal not being able to fully close. It can also protect against anencephaly, a condition in which the brain does not develop. Babies born with anencephaly usually die before or shortly after they are born.  Women who are pregnant or are trying to get pregnant are recommended to take 400 to 800 micrograms of folic acid per day.
It is possible for folic acid to reduce chances of spinal or brain defects by nearly 70%. These diseases are known as neural tube defects which always occur when the spinal cord fails to close properly during development which is what spina bifida is. 
Folic acid ultimately reduces the level of a potentially harmful compound called homocysteine. This is done by speeding up the conversion of homocysteine to methionine, a nontoxic amino acid that the human body prefers and needs. Scientists and researchers discovered that locking the enzyme MTHFR to its cofactor FAD allows folic acid to perform its unique function in the human body. Therefore, the Food and Drug Administration recommends all women of child-bearing age to supplement her diet with folic acid to prevent potential birth defects from occurring.
Side effects of taking folic acid include a skin rash, itchiness, redness, or difficulty breathing.
Folic acid can also be ingested through a balanced diet. This includes, fortified cereals, whole grains, fruits, veggies, beans, and other natural protein. Those looking to increase folic acid intake due to pregnancy can do it naturally through diet or both with supplements and food. It is important for males also to not neglect folic acid. Although they do not benefit from the birth defect preventions, folic acid is still a healthy supplement that is necessary in small doses. 
It is commonly seen that folic acid can minimize the chromosomal defeats in sperm. Thus, folate is an important source for fertility in both men and women because it contributes to spermatogenesis. Basically, for both gender, it is crucial to receive a good amount of folate through the diet to avoid subfertility.
Using folic acid will reduce homocysteine levels, but it will not minimize cardiovascular disease. However, this applies differently for women who are pregnant. Consuming folic acid during pregnancy may reduce the risk of heart defects in infants, which is a good thing. It may also reduce the risk for children to develop a syndrome called the metabolic syndrome.
Even though taking folic acid does not reduce heart disease, it appears to reduce the risk of stroke. However, there are many reviews that indicate how only some individuals who take folic acid may in return minimize the risk of stroke. In other words, folic acid may only work on some people. It is being said that stroke reduction is consistent with the reduction in pulse pressure produced by folate supplementation of 5 mg per day. So for those who are likely to get heart disease, it is important to consume folate in every day diet. This is the reason why hyperhomocysteinemia or stroke patients are greatly encouraged by their doctors to take daily vitamin B which includes folic acid. Folic supplements are in expensive and are quite safe to use, but do not overdo it.
Since many cancer cells tolerate folic acid and overexpress the folic acid receptor, this had led to the creation of anti-cancer drugs that target the folic acid receptor. There are investigations that proved that good levels of folic acid may be related to lower risk of stomach, esophageal, and ovarian cancers. However, the benefits of folic acid against cancer may only depend on when an individual is taking it and on the conditions of that particular person. This is because everyone tends to have a different immune system that reacts to certain things differently.
Moreover, for individuals who are already suffering from cancer or from precancerous condition may find that taking folic acid may not be helpful and can be damaging. Therefore, consuming a certain amount of folic acid is crucial for everyday diet, but it is important to note that excess of folate may promote tumor initiation. High folate intake promotes advanced carcinogenesis and low folate intake protects against early carcinogenesis. Hence, many doctors and public health recommend being super careful when taking folate and encourage not to intake too much folate.
Diets that are high in folate are related with the decreased risk of colorectal cancer. There are some researches that show how the association is stronger for folate that are taken from foods than folate from supplements. In relation to folate and one carbon metabolism, colorectal cancer is the most studied type of cancer. Furthermore, there are epidemiologic studies that suggest diets high in folate are associated with decreased risk of breast cancer. Studies also show that high dietary folate intake will minimize the risk of prostate cancer. Overall, there had been many studies dealing with folate acid to prevent many kinds of disease.