Folic Acid (Vitamin B9): Benefits, Who Should Take It, Deficiency Symptoms, and Foods
Folic acid, also known as vitamin B9, is a vital vitamin with essential biological functions in the human body, particularly in cell division and the synthesis of DNA and RNA.
What Is Folic Acid?
Folic acid is a member of the B-vitamin family, which plays a role in regulating various metabolic and biochemical processes in the body. Other B-vitamins include vitamin B1 (thiamine), B2 (riboflavin), B3 (niacin), B5 (pantothenic acid), B6 (pyridoxine), B7 (biotin), and B12 (cyanocobalamin).
What Are the Symptoms of Folic Acid Deficiency?
Folic acid deficiency typically doesn’t occur in isolation but often coincides with the deficiency of other nutrients such as vitamin B6 and vitamin B12. This deficiency can be associated with poor dietary habits, excessive alcohol consumption, malabsorption in the gastrointestinal tract, or certain intestinal disorders. Symptoms of folic acid deficiency include:
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Anemia
Folic acid plays a crucial role in the formation of red blood cells. Folic acid deficiency can lead to a reduced red blood cell count, resulting in anemia. Anemia symptoms include fatigue, weakness, dizziness, rapid heartbeat, and pale skin.
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Digestive Issues
Folic acid deficiency can lead to oral ulcers, tongue inflammation, and indigestion. These problems can cause symptoms such as mouth pain, loss of appetite, and digestive discomfort.
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Nervous System Problems
Folic acid is essential for the normal functioning of the nervous system. Folic acid deficiency can lead to nervous system issues, including memory decline, lack of concentration, mood swings, and anxiety.
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Immune System Issues
Folic acid deficiency may also affect the immune system’s function, making the body more susceptible to infections.
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Fetal Neural Tube Defects
For pregnant women, folic acid deficiency can have a significant impact on fetal neural tube development, increasing the risk of defects such as spina bifida.[1][3]
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Heart Health
Some studies suggest a link between folic acid deficiency and an increased risk of heart disease.
Folic Acid Benefits
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Prevention of Brain Degeneration: Dementia, Cognitive Function, Alzheimer’s Disease
Studies have indicated that elevated levels of homocysteine in the body are positively associated with the incidence of Alzheimer’s disease and dementia. High homocysteine levels are thought to negatively impact brain function by causing issues such as neuronal cell death due to brain ischemia, inhibition of methylation reactions, tau protein deposition, and more.
In addition, studies have observed a correlation between low folic acid levels in the body and poorer cognitive function, higher rates of dementia, and Alzheimer’s disease. While not all studies support the idea that supplementing folic acid can help improve cognitive impairment, when considering both folic acid and homocysteine levels in the body, supplementing folic acid does appear to aid in improving cognitive abilities.[4]
💡 One clinical study found that in individuals with elevated homocysteine levels but normal vitamin B12 levels, daily supplementation of 800 micrograms of folic acid significantly reduced homocysteine levels by 26% and notably improved cognitive function, memory, and information processing speed.[5]
💡 Another study administered 400 micrograms of folic acid and 100 micrograms of vitamin B12 daily to patients with depression, resulting in significant improvements in cognitive function, especially in immediate and delayed memory performance.[6]
💡 Furthermore, other studies have suggested that simultaneous supplementation of folic acid with vitamin B6 and vitamin B12 can reduce high homocysteine levels in the body, further preventing and delaying the decline in cognitive abilities, and may even have a preventive effect against Alzheimer’s disease.[7]
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Prevention of Neural Tube Defects
Folic acid is crucial during rapid cell growth phases due to its involvement in DNA synthesis and cell replication. While the exact mechanisms are not fully understood, many clinical studies have confirmed that supplementing folic acid during pregnancy can prevent a significant proportion of newborns from developing neural tube defects.[8]
In 1992, U.S. public health authorities recommended that every pregnant woman should consume 400 micrograms of folic acid daily to prevent neural tube defects in newborns. Starting in 1998, U.S. regulations required the addition of extra folic acid to grain products (such as bread, flour, and pasta). For every 100 grams of grain product, there should be an additional 140 micrograms of folic acid. Since the implementation of this policy, the incidence of neural tube defects in newborns in the United States has significantly decreased.[9]
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Improved Mood
Research has shown an association between low folic acid levels in the body and depression. While not all studies have consistent results, most have observed similar trends. A population-based study found that higher blood folic acid levels were associated with a lower incidence of depression.[10]
Another study found that unhealthy dietary patterns and excessive alcohol consumption could lead to reduced blood folic acid levels, which were subsequently associated with the occurrence of depression. Moreover, severe depression patients were found to have significantly lower folic acid levels in their bodies compared to those who had never experienced depression. From an epidemiological perspective, it is indeed observed that the concentration of folic acid in the body is inversely related to the onset of depression.
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Prevention of Cardiovascular Disease and Stroke
Elevated homocysteine levels are associated with an increased risk of cardiovascular disease, and folic acid, along with other B-vitamins, participates in homocysteine metabolism in the body. Related research suggests that reducing homocysteine levels in the body can help lower the risk of cardiovascular disease.
💡 In one clinical study, patients with cardiovascular disease or diabetes were given additional folic acid (capsules containing vitamin B6 and vitamin B12), resulting in a significant reduction in homocysteine levels and a 25% reduction in the risk of stroke. However, this study did not observe a significant difference in the risk of improving heart attacks with folic acid.[12]
Foods Rich in Folate
There is a wide variety of foods that contain folate, with green leafy vegetables being one of the richest sources.[1][3]
| Category | Food |
|---|---|
| Green Leafy Vegetables | Spinach, Romaine lettuce, kale, mustard greens, celery, scallions, cabbage, etc. |
| Legumes and Legume Products | Soybeans, chickpeas, fava beans, green beans, red beans, black beans, lentils, etc. |
| Orange and Dark Green Fruits | Oranges, bananas, strawberries, pineapples, mangoes, watermelons, etc. |
| Grains and Grain Products | Oats, bread, pasta, cereal grains, etc. |
| Nuts and Seeds | Peanuts, walnuts, sesame seeds, hazelnuts, etc. |
| Meat and Animal Products | Chicken liver, beef liver, etc. |
| Seafood | Salmon, mackerel, etc. |
How Much Folate Should You Consume?
The general recommended daily intake for adults is approximately 400 micrograms (0.4 milligrams) of folate. This recommended amount helps maintain normal physiological functions.[13]
Pregnant women typically require more folate, with a daily recommended intake of about 500 to 600 micrograms (0.5 to 0.6 milligrams).[14]
Breastfeeding mothers may also benefit from additional folate, with the same recommended intake as pregnant women, to ensure an adequate folate content in breast milk.
