Folic acid, also known as vitamin B9, is an essential nutrient that plays many important roles in the body. A lack of folic acid can lead to a variety of health problems.
What is folic acid?
Folic acid is a B vitamin that is naturally found in many foods, including dark green leafy vegetables, citrus fruits, beans, and fortified breads and cereals. It is a water-soluble vitamin, which means the body does not store it. This means you need to consume folic acid from foods or supplements regularly to maintain adequate levels.
Folic acid works closely with vitamin B12 and vitamin C and helps the body produce and maintain new cells. It is crucial during periods of rapid cell division and growth, such as infancy, adolescence, and pregnancy.
Why do we need folic acid?
Folic acid has several important functions in the body:
- Cell growth and division – Folic acid is necessary for cell replication and division. It helps the body produce new cells and replace old ones.
- DNA and RNA synthesis – Folic acid is required to synthesize DNA and RNA. It provides one-carbon units needed to form the building blocks of DNA.
- Red blood cell production – Folic acid helps produce and maintain new red blood cells. Red blood cells carry oxygen throughout the body.
- Amino acid metabolism – Folic acid helps the body metabolize amino acids, the building blocks of proteins.
- Gene expression – Folic acid plays a role in regulating gene expression by controlling DNA methylation.
- Immune function – Adequate folic acid levels support the production and function of white blood cells involved in immune response.
- Mental health – Folic acid is linked to the production of neurotransmitters like serotonin that regulate mood.
- Heart health – Along with B12 and B6, folic acid helps regulate levels of homocysteine, an amino acid linked to heart disease risk.
Because of these critical bodily functions, adequate folic acid intake is vital to good health.
How much folic acid do you need?
The recommended daily intake for folic acid depends on age:
| Age | Recommended Amount |
|---|---|
| Infants up to 12 months | 65 mcg |
| Children 1-3 years | 150 mcg |
| Children 4-8 years | 200 mcg |
| Children 9-13 years | 300 mcg |
| Adolescents 14-18 years | 400 mcg |
| Adults | 400 mcg |
| Pregnant women | 600 mcg |
| Breastfeeding women | 500 mcg |
Because the body does not store folic acid, you need to consume some from food and supplements every day to meet your needs.
What causes folic acid deficiency?
There are several potential causes of folic acid deficiency:
- Inadequate dietary intake – Not eating enough folate-rich foods can lead to deficiency over time.
- Malabsorption – Conditions affecting the digestive system, like celiac disease, can impair nutrient absorption.
- Pregnancy and breastfeeding – Requirements are increased, raising needs.
- Certain medications – Some drugs like methotrexate and phenytoin increase folate requirements.
- Alcohol abuse – Heavy drinking can cause deficiency and hinder absorption.
- Genetic mutations – Some genetic disorders can impair folic acid metabolism.
Groups most at risk of folic acid deficiency include pregnant women, the elderly, alcoholics, and those with digestive disorders or chronic illnesses.
What are the symptoms of folic acid deficiency?
Folic acid deficiency can cause a wide range of symptoms. Some common signs include:
- Fatigue and weakness
- Heart palpitations
- Shortness of breath
- Irritability and mental confusion
- Depression
- Sore tongue
- Headaches
- Difficulty concentrating and remembering
- Pale skin
- Diarrhea or constipation
- Loss of appetite
- Weight loss
- Muscle aches and cramps
- Numbness and tingling in the extremities
In infants and children, folic acid deficiency can also cause poor growth, delayed motor skills, and behavioral disorders.
What health problems are linked to folic acid deficiency?
Prolonged folic acid deficiency can increase the risk of developing the following conditions:
Anemia
One of the most common consequences of folic acid deficiency is anemia. Folic acid helps produce and maintain new red blood cells. Without adequate folic acid, the body cannot make enough red blood cells, resulting in anemia.
Birth defects
Folic acid deficiency in early pregnancy significantly increases the risk of neural tube defects like spina bifida. It may also raise the risk of other birth defects like cleft lip and palate.
Cardiovascular disease
Low folic acid is linked to high homocysteine levels, an amino acid that damages blood vessels. Elevated homocysteine levels are associated with a higher risk of heart disease, stroke, and blood clots.
Cancer
Research shows that inadequate folic acid intake may increase cancer risk, especially colon cancer. Folic acid plays a key role in DNA synthesis and repair.
Neuropsychiatric disorders
Folate deficiency has been associated with a higher incidence of depression, schizophrenia, bipolar disorder, and cognitive decline. Impaired brain function related to folic acid deficiency may contribute.
Kidney disease
Individuals with kidney disease have an increased risk of folic acid deficiency. Kidney dysfunction can impair folic acid activation and excretion, resulting in deficiency.
Dementia
Observational studies link low blood folate levels with higher rates of cognitive decline and dementia. Folic acid deficiency could accelerate brain aging.
How is folic acid deficiency diagnosed?
Folic acid deficiency is diagnosed through blood tests measuring folate levels. Normal lab ranges are:
| Age | Normal Folate Level |
|---|---|
| Children | 5.7-24.4 ng/mL |
| Adults | 5.9-24.8 ng/mL |
| Pregnant women | 12.5-44.4 ng/mL |
Levels below 2 ng/mL indicate a folic acid deficiency. Your doctor may also check complete blood count (CBC), vitamin B12, iron, and homocysteine levels.
How is folic acid deficiency treated?
Treatment for folic acid deficiency involves supplementing with folic acid and consuming more folate-rich foods. Most people can correct a deficiency by taking 400-1000 mcg folic acid tablets daily for 3-4 months.
It’s also important to address any underlying causes. Treatment may involve:
- Taking supplements to improve nutrient absorption
- Modifying medications that interfere with folate
- Abstaining from alcohol
- Consuming a balanced diet with adequate calories and protein
- Treating conditions inhibiting folate metabolism
People with deficiency symptoms should meet with a doctor to develop a treatment plan catered to their needs.
What foods are high in folic acid?
The best dietary sources of folic acid include:
| Food | Folate per serving |
|---|---|
| Lentils, cooked | 179 mcg (45% DV) |
| Spinach, cooked | 131 mcg (33% DV) |
| Black-eyed peas, cooked | 105 mcg (26% DV) |
| Asparagus, cooked | 89 mcg (22% DV) |
| Brussels sprouts, cooked | 78 mcg (20% DV) |
| Broccoli, cooked | 57 mcg (14% DV) |
| Avocado | 59 mcg (15% DV) |
| Oranges | 40 mcg (10% DV) |
Folate is also added to many common foods like cereals, breads, pasta, and rice. Check the label for “% Daily Value” of folic acid.
Can you get too much folic acid?
High folic acid intake from supplements or fortified foods can cause adverse effects in some people. Too much folic acid may:
- Mask vitamin B12 deficiency, allowing neurological symptoms to progress
- Interfere with certain anticonvulsant medications used to treat epilepsy
- Reduce the response to treatment in malaria patients
- Potentially increase risk of prostate and lung cancer
Tolerable upper intake levels (UL) have been established to avoid toxicity:
| Age | Upper Tolerable Limit |
|---|---|
| 1-3 years | 300 mcg |
| 4-8 years | 400 mcg |
| 9-13 years | 600 mcg |
| 14-18 years | 800 mcg |
| Adults | 1000 mcg |
Consuming very high amounts through supplements long-term can potentially lead to intestinal distress, sleep disturbances, irritability, skin reactions, and seizures in those predisposed.
Conclusion
Folic acid is an essential B vitamin needed for many bodily processes like cell division, DNA synthesis, and red blood cell formation. Inadequate folic acid can result in anemia, birth defects, heart disease, stroke, cancer, and neurological disorders.
Groups at high risk for deficiency include pregnant women, the elderly, alcoholics, and those with digestive disorders or chronic disease. Symptoms include fatigue, weakness, headaches, and mental confusion.
Testing blood folate levels can confirm folic acid deficiency. Treatment involves folic acid supplementation and dietary changes to increase intake from folate-rich foods. Ensuring adequate intake can help maintain good health and prevent serious complications.