Folic acid is the supplemental form of folate, also known as vitamin B9. All forms of B9 are vital to good health, which is why proper folate intake should be monitored, and why daily folic acid supplementation is a common recommendation.
The names "folic acid" and "folate" are not interchangeable. "Folate is a general term used to describe the many different forms of vitamin B9, [including] folic acid," explains the Centers for Disease Control and Prevention (CDC). "Folic acid is the synthetic ... form of folate that is used in supplements and in fortified foods." Once absorbed into the body, synthetic folic acid is converted into metabolically active folate.
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How Much Folate Do You Need?
Whatever form it's consumed in, vitamin B9 is crucial to several important metabolic processes, meaning that certain chemical reactions do not occur unless the vitamin is present. Additionally, most excess folate is excreted in the urine instead of being stored in the body's fat tissue.
"Your blood levels will get low after only a few weeks of eating a diet low in folate," notes the U.S. National Library of Medicine (NLM). That's why it's so important to make sure that you are getting a good amount of folate every single day.
The safe daily maximum amount of B9 is set at 1,000 micrograms. The CDC's current intake recommendation for vitamin B9, whether consumed as folate or folic acid, is 400 micrograms per day for most adults. But some people need more.
The U. S. Department of Health and Human Services' Office of Women's Health (OWH) states that alcoholics, people on certain medicines to treat seizures, anxiety or arthritis, and women who are pregnant or trying to get pregnant may need up to 400 micrograms of supplemental B9 each day in order to avoid folate deficiency.
"Getting enough folic acid before and during pregnancy can prevent major birth defects of [the] baby's brain or spine," notes the NLM.
Folic Acid Supplementation
If you eat a balanced diet that includes a lot of folate-rich foods, you should have a fairly high B9 intake. However, the CDC notes that "it is very difficult for most women to get the daily recommended amount of folate through food alone." Taking a multivitamin will bolster your body's stores of the crucial nutrient and ensure that you get the proper amount of B9.
It is generally safe to take folic acid every day. However, you should talk with your healthcare provider to determine whether supplementation is a good idea for you, based on your current dietary needs and habits. She or he can advise you as to how much folic acid you can take as your daily dose.
"Yes, you can get too much folic acid, but only from man-made products such as multivitamins and fortified foods," notes the OWH. "You can't get too much from foods that naturally contain folate."
Serious folate deficiency, on the other hand, is not common. But it can occur. Symptoms include fatigue, a tender tongue, irritability, diarrhea and certain types of anemia, according to the NLM.
Sources of Folate
Synthetic folic acid isn't just found in multivitamins and supplements. It's also in fortified foods such as breakfast cereals, breads and grain products. Meanwhile, the best plant source of natural folate is cooked-from-dry beans such as lentils and black-eyed peas.
B9 is also found in spinach and other green leafy vegetables, citrus fruits, asparagus and nuts. But it's meat eaters who really have the edge with folate: Because some excess B9 is stored in the liver, animal liver is by far the best natural source of the nutrient, according to the USDA.
One cup of cooked liver — whether it be chicken, turkey, duck, pork, lamb or beef — contains more B9 than plants do. A 100-gram serving of cooked beef liver, for example, has 253 micrograms of folate. By comparison, the same-size serving of cooked lentils has 181 micrograms, and cooked spinach, 146.
A study of cooked chicken liver published in the October 2020 issue of Foods found that processed chicken liver was a rich natural source of B9. "The consumption of the processed liver should be encouraged," concluded the researchers. "Additionally, in terms of food preparation, sous-vide (60 °C/75 min), steaming and grilling can be recommended for liver preparation in households or food services as an ideal way to maintain maximum folate retention."
Folate and Folic Acid Function
Vitamin B9 is vital to health. Here are two of the ways it keeps you alive and thriving.
Red Blood Cell Production
The body needs folate in order to make RNA and DNA , so it is literally essential for life. It's also a required ingredient in the creation of red blood cells, which transport oxygen to all parts of the body and carry carbon dioxide to the lungs to be exhaled.
Formed in the bone marrow, red blood cells are an important element of blood, which the NLM calls "the river of life." It takes about two days for a new red blood cell to form completely, and almost two million of them are produced every single second.
This incredible production rate requires a constant supply of folate and other nutrients. If you have a folate deficiency, the formation of genetic material to produce new red blood cells slows, leading to decreased bone marrow productivity. As old red blood cells die, there are not enough new red blood cells to take their place, which eventually can lead to anemia, per the OWH.
Nervous System Development
The reason folic acid is added to processed foods in the United States is to reduce the incidence of nervous system-related birth defects. "In many scientific studies done in countries around the world, folic acid has been shown to be effective in preventing neural tube defects," says the CDC.
The role of folate in the production of new cells is particularly important to fetal development during the early weeks of pregnancy, when the brain and spinal cord form. A folate deficiency in the mother during this period increases the risk of nervous system birth defects in the child, specifically, anencephaly and spina bifida, according to the OWH.
With anencephaly, the brain and skull fail to develop normally in the womb, often resulting in miscarriage or stillbirth. Babies born alive with anencephaly typically die shortly after birth.
Spina bifida describes abnormal development of the lower spinal cord, which varies in severity. The defect is minor in some babies, but severe spina bifida may cause lifelong disability.
- U.S. National Library of Medicine: "Folic Acid"
- U.S. National Library of Medicine: "B Vitamins"
- Centers for Disease Control and Prevention: "Folic Acid — General Information About NTDs, Folic Acid, and Folate"
- U.S. National Library of Medicine: "Folate Deficiency"
- U.S. Department of Agriculture: "Beef, Variety Meats and By-products, Liver, Cooked, Braised"
- U.S. Department of Agriculture: "Spinach, Cooked, Boiled, Drained, Without Salt"
- U.S. Department of Agriculture: "Lentils, Mature Seeds, Cooked, Boiled, Without Salt"
- Foods: "Effect of Different Cooking Methods on Folate Content in Chicken Liver"
- U.S. Department of Health and Human Services: "Office on Women's Health — Folic Acid"
- U.S. National Library of Medicine: "Red Blood Cell Production"