Introduction
The B-complex vitamin group encompasses eight vitamins: thiamin, riboflavin, niacin, vitamin B6, pantothenic acid, biotin, vitamin B12, and folic acid. All are considered water soluble vitamins. They function as coenzymes which are essential for the activation of most enzymes. Without enzymes, most chemical reactions in the cells would come to a halt. General information about B vitamins was discussed in Peyk #174. In this issue, we will discuss the importance of folate in the diet and in general health.
Is folate the same as folic acid?
Both folate and folic acid are considered different forms of B vitamin. Folate occurs naturally in foods and it is also known as vitamin B9. The name folate is derived from the Latin word “folium,” which means foliage or leaf. So leafy vegetables are a good source of folate. Folic acid, on the other hand, is the synthetic form of folate and it is rarely found in a food source. The terms “folic acid” and “folate” are often used interchangeably. Folic acid is mostly used in supplements and in fortified foods such as rice, flour, pasta, and most breakfast cereals (1). Manufacturers fortify foods with folic acid rather than folate because folic acid is more stable during cooking or baking. Like other B vitamins, folate and folic acid are water soluble and generally are not stored in the body. Therefore, they need to be incorporated into the daily diet.
Absorption rate
Folic acid is a simpler molecule than folate and is absorbed faster. Both folate and folic acid need to be converted to their active form to be effectively used by the cells. Regardless of slight differences in their chemical composition and the rate of absorption, once inside the cells, both folate and folic acid will function equally well.
Effects of heat and cooking
Cooking destroys most water-soluble vitamins, including folates. Folate-rich foods can lose most of their folate when exposed to heat and light. Therefore, raw foods contain more folate than cooked foods. On the other hand, cooking or steaming vegetables makes folates more bioavailable. Folic acid found in fortified foods is more bioavailable and almost all will be absorbed.
Functions and benefits
Like other B vitamins, folic acid acts as a coenzyme in many metabolic processes in the body. As a coenzyme, it binds to enzymes to activate them. Enzymes are special protein molecules that are responsible for running chemical reactions, such as forming new products, cell growth, and—most importantly—formation of energy (ATP, or adenosine triphosphate, a chemical energy or energy of life). Without energy, no life can exist, and enzymes and coenzymes are essential parts of the life cycle.
Formation of DNA– DNA (deoxyribonucleic acid) is the blueprint for what each organism should be. It controls functions of the cells and production of proteins and enzymes that are essential for life.
When a cell divides and multiplies, the DNA needs to be duplicated as well, so that each new cell has a copy of the DNA. Formation of DNA requires the presence of amino acids and special enzymes. The role of folate in this process is to synthesize some of the nonessential amino acids necessary for synthesis of DNA. If the synthesis of DNA is disrupted, the body’s ability to create and maintain new cells is impaired.
Formation of red blood cells – Folate plays a crucial role in cell growth and formation of red blood cells.
During red blood cell formation, many enzymes are involved, and the enzymes require coenzymes for activation of the enzymes. Folate works as a coenzyme necessary for the formation of heme, the pigmented, iron-containing portion of the hemoglobin in red blood cells.
Preventing birth defects – Because of its participation in DNA synthesis, folate plays an extremely important role during pregnancy, particularly in the first few weeks after conception. Embryonic cells divide very rapidly and a folate deficiency during early pregnancy can result in deformity of the brain and spinal cord, such as anencephaly and spina bifida. Studies show that increased folic acid consumption by the mother reduces the risk of these birth defects by 50 to 70 percent (4).
Heart disease – According to the Center for Disease Control (CDC), the results of experiments involving more than 80,000 people suggest a 10% lower risk of stroke and a 4% lower risk of overall cardiovascular (heart and blood vessel) disease among those taking folic acid supplements. However, it should be noted that folic acid doesn’t seem to prevent strokes.
Blood pressure – Studies show that taking folic acid daily for at least 6 weeks reduces blood pressure in people with high blood pressure.
Kidney disease – One analysis for identifying kidney disease is looking at the level of the amino acid homocysteine in the blood. An increased level of this product has been linked to some form of kidney disease. Studies have shown that taking folic acid lowers homocysteine levels by 20% to 30% in people with elevated homocysteine levels (8).
Cancer- Inadequate amounts of folate in the body can disrupt a cell’s DNA and prevent growth and repair of the immune system, potentially triggering the development of cancer cells that grow without control. In particular, folate has been shown to help reduce the risk of colon cancer. Studies show that men and women who are deficient in dietary folate have a higher risk of developing colon cancer. Other studies have found an association between diets low in folate and an increased risk of breast and pancreatic cancers. Patients who are being treated for cancer should discuss with their physician before taking supplements that contain folic acid because folic acid supplements can interfere with some drugs used to treat cancer.
Folate and vitamin B12
Both vitamin B12 and folate are essential coenzymes in the synthesis of DNA, RNA, and myelin in the nervous system and are necessary for normal red blood cell formation. Without either of the two, formation of normal red blood cells will be adversely affected.
Deficiency of folate
A diet lacking foods rich in folate or folic acid can lead to a folate deficiency. Although deficiency of the vitamin is not common, folate deficiency can occur in people who have certain conditions, such as celiac disease, that prevent the small intestine from absorbing nutrients from foods (6).
Neural defect – A low level of folate is associated with an increased risk of several health conditions. Studies have shown that low folate levels in pregnant women have been linked to birth abnormalities, such as neural tube defects and abnormal spinal cord.
Red blood cell formation – Research indicates that a folate deficiency interferes with normal red blood cell division and results in abnormally large and immature red blood cells that are not efficient in caring oxygen. A folate deficiency has been shown to cause anemia, especially if you have digestive problems, kidney or liver disease, or drink too much alcohol (1).
Daily need for folate
For most people, it’s best to get folate from food. A balanced diet usually provides all you need. The recommended and required daily allowance (RDA) of folic acid is 400 micrograms (μg) per day for adult males and females, which can be provided through vegetables or as a supplement (6). Women who want to be pregnant should consume additional folic acid from fortified foods or supplements. Women who have already had a pregnancy affected by a neural tube defect should consult with their healthcare provider before taking any supplement. The upper limit for a folic acid supplement is set to be 1,000 μg/day.
Possible side effects and interactions
Before taking any supplements, it is highly recommended to consult with your physician because there might be some side effects with different medications. Reports from the Mayo Clinic show that taking folic acid supplement can decrease the effectiveness of some drugs such as some anticonvulsants, Barbiturates, Methotrexate, and Pyrimethamine (Daraprim).
Overdose and toxicity
Toxicity of folate is rare, and research does not show any side effects in consuming excessive amounts of naturally occurring folate in foods. Normally, excess folic acid is excreted in urine. However, consuming too much folic acid, either through supplements of fortified foods or pills, can be harmful for individuals who are deficient in vitamin B12 (7).
Food sources of folate
Foods that are naturally high in folate include leafy vegetables (such as spinach, broccoli, and lettuce), okra, asparagus, fruits (such as bananas, melons, and lemons), beans, yeast, mushrooms, meat (such as beef liver and kidney), orange juice, and tomato juice. Since 1998, folic acid has been added to cereals, flour, breads, rice, pasta, bakery items, cookies, and crackers, as required by federal law.
The figure below compares the content of folate in some food sources (adopted from reference 4).
Summary
Folate is a natural form of vitamin B9. Folic acid is a synthetic form of folate, and manufacturers add it to all enriched grains and cereal products. Both forms are used interchangeably, and function equally well when absorbed to the body. The most important functions of folic acid are production of DNA and development of new cells especially red blood cells. Good sources of folate are dark green leafy vegetables such as spinach, broccoli, asparagus, dried peas, and beans.
Selected sources
1- https://www.webmd.com/vitamins/ai/ingredientmono-1017/folic-acid
2- https://www.healthline.com/nutrition/folic-acid-vs-folate#folate
3- https://www.cdc.gov/ncbddd/folicacid/about.html
4- Nutrition: From Science to You, Joan Salge Blake, Kathy D Munoz, and Stella Volpe-3rd ed. 2016, Pearson Education, Inc.
5- Nutrition and Diet Therapy: Evidence-Based Applications, 4th Ed. Lutz, Carroll and Przytulski K., F. A Davis Company, Philadelphia, 2006.
6- https://www.mayoclinic.org/drugs-supplements-folate/art-20364625
7- https://www.medicalnewstoday.com/articles/327290.php#differences
8-https://www.hopkinsmedicine.org/health/conditions-and-diseases/folate-deficiency-anemia
