Introduction
Vitamin B9, or folate, is a water-soluble B vitamin found naturally in food, while folic acid is its synthetic form used in supplements and fortified foods. The crystalline form of folic acid is often better retained than folate from food sources.
What does vitamin B9 do?
Vitamin B9 supports DNA and RNA formation, protein digestion, and red blood cell production. It helps break down excess homocysteine and plays a key role in metabolism and cell replication. Adequate intake is crucial during fetal and childhood brain development.
Folate deficiency can lead to heart disease, neural tube defects, anemia, low white blood cell and platelet counts, and high homocysteine levels. It is also linked to increased risks of cancer, childhood depression, and cognitive impairment. (1)(2)(3)
How Does Vitamin B9 Function in Your Child's Body?
Folate is crucial for DNA replication, repair, methylation, and synthesizing nucleotides, amino acids, and some vitamins. Adequate intake helps prevent deficiencies and related health issues. While supplements can help, prioritizing folate-rich foods is recommended, with medical guidance for significant deficiencies.
Folate is absorbed in the duodenum and jejunum of the small intestine and transported via the brush border membrane. Research suggests gut bacteria, including those in the colon and proximal small intestine, can synthesize folate, supplementing dietary intake. (4)
Synthetic folic acid is absorbed directly into the bloodstream, allowing for more efficient uptake. It is then converted in the blood for easier metabolism and transport to where it is needed in the body. (1)
What is Vitamin B9 Good for?
Vitamin B9 is used to prevent and treat various conditions. Research shows folate supplementation improves vitiligo symptoms, helps manage high blood pressure from kidney issues in children, and reduces gum swelling, ulcers, and bleeding caused by the anti-seizure medication Phenytoin.
Below are several more benefits of vitamin B9 for your entire family, along with the science to back them: (2)(5)
- Cognitive development
- Cancer prevention
- Heart disease prevention
- Depression prevention
- Improved blood sugar levels
Cognitive development:
Vitamin B9 is vital for brain development, memory, learning, and mental health in children. Adequate intake supports academic performance and can help address challenges like learning disabilities, depression, and memory issues.
Research Support:
Observational studies have found an association between high homocysteine levels as well as increased incidence of Dementia and Alzheimer’s disease. Elevated homocysteine can negatively affect the brain by causing a lack of blood to the brain and nerve cells. Additional observational studies have found a link between low folate in blood levels and higher risk of Dementia. However, clinical trials have not found that folic acid supplementation directly prevents the development of Dementia or improves cognitive function, even if it reduces homocysteine levels. (2)
Cancer prevention: Vitamin B9 plays a significant role in cell replication; therefore, an adequate amount can prevent mutations in the cell. Early cases of childhood cancers are also connected to low folate intake, so folate can be a key nutrient in cancer prevention for children.
Research Support:
Observational studies show that people who get above average amounts of folate from their diets or folic acid supplements over the course of 15 years or more have lower risks of colon cancer and breast cancer. When looking at the relationship between any vitamin supplement and cancer, like folic acid with methotrexate, it is important to remember that cancer cells are essentially our own cells on overdrive, growing and rapidly dividing; therefore, they have a greater need for nutrients than most of our normal cells do. In fact, one successful chemotherapy agent works to prevent cells from using folic acid, which can hinder rapid cell division and therefore treat the spread of cancer. (2)
Heart disease prevention:
Cardiovascular events are a leading cause of death in the US, including among children and adolescents. Nutritional influences are studied for heart disease prevention and treatment, especially in congenital heart disease. Consult a physician for proper care of children with heart conditions.
Research Support:
Several randomized trials have tested for the effects of B vitamins on homocysteine levels and prevention of heart disease and stroke. The studies found that taking high doses of vitamins B6, B12 and B9 (folic acid) lowered homocysteine levels in individuals who have had a history of or were at high risk of heart disease or stroke. Additional randomized control trials reported a 10% lower risk of stroke and 4% lower risk of overall cardiovascular diseases with folic acid supplementation. (2)
Prevents depression:
Children with depression treated with antidepressants show improved mental health with adequate folate (vitamin B9) levels, from food or supplements. Consulting both a pediatrician and mental health professional can support a holistic approach to treating child depression.
Research Support:
The use of folic acid for depression, or folate for depression, has been studied in research over the years. One study showed that taking supplements with folate (including folic acid and methylfolate) alongside prescribed antidepressant medications aided in the improvement of depression and child depression symptoms at a higher rate than those who took antidepressants alone. Therefore, ensuring healthy nutrition can be beneficial in child depression treatment. (6)
Improve blood sugar levels:
Kids with a genetic predisposition to diabetes should ensure sufficient vitamin B9 intake to help prevent childhood diabetes. Folate is important for managing diabetes, and a nutritionist or dietitian can assist in creating a balanced diet to meet these needs.
Research Support:
Research on folic acid and diabetes has suggested that folate-based supplements may help improve blood sugar control, reduce insulin resistance, and enhance cardiovascular function in those with diabetes. These supplements may also help reduce diabetic complications, including neuropathy. (7)
What are the Symptoms of Vitamin B9 Deficiency?
Vitamin B9 is crucial for health at all ages, supporting the biosynthesis of nucleotides, amino acids, neurotransmitters, and vitamins, as well as tissue growth. Ongoing research links folic acid deficiency and impaired folate pathways to various diseases across the lifespan.
Folate is vital for DNA formation, cell replication, and numerous functions. A deficiency in vitamin B9 can lead to DNA alterations and anemia.
Below are some common causes of folate deficiency:
- Intestinal surgeries or digestive disorders that cause malabsorption: Celiac disease and inflammatory bowel disease can impede the absorption of folate. Surgeries involving the digestive organs or that reduce the normal level of stomach acid may also interfere with absorption.
- Genetic variants: People carrying a variant of the gene MTHFR cannot convert folate to its active form to be used by the body.
- Lack of vitamins in your diet: Vitamin deficiency can happen if a child follows a fad diet or has a generally poor diet for a long time. This cause is more common in developing, impoverished and under-nourished societies. (2)(8)
Symptoms of vitamin B9 deficiency:
A deficiency of this vitamin can cause a wide range of problems, and you might be able to spot folate deficiency in your child early on if you notice these signs and symptoms:
- Disturbed vision
- Problems with memory, understanding and judgment
- Extreme tiredness/fatigue
- Muscle weakness
- Lack of energy
- Pins and needles sensation
- Soreness and redness of the tongue
- Mouth ulcers
- Psychological problems, which may include depression and confusion
- Headache
- Dizziness
- Paleness
- Shortness of breath
Disturbed vision:
While a direct link between vitamin B9 and improved vision is not proven, research suggests that vitamin B9, along with vitamins A, B6, and B12, supports vision clarity and may reduce long-term risks like age-related macular degeneration. (9)
Research Support:
Folic acid deficiency also leads to an abnormal accumulation of homocysteine. Increased retinal homocysteine induces retinal neuron death, altering the inner and outer retinal layers and affecting the cells of the ganglion cell layer. Some clinical studies have implicated homocysteine in maculopathy, open-angle glaucoma, and diabetic retinopathy. Lack of folate is also involved in nutritional optic neuropathy, which is characterized by damage to the retinal nerve fiber layer. In a patient diagnosed with folate deficient optic neuropathy, folate deficiency is presented as a visual abnormality with a 4-week history of progressive visual loss. Bilateral retrobulbar optic neuropathy was also found to be present. Investigations revealed severe folate deficiency. Subsequent correction of the folate levels with oral supplementation improved the patient’s visual acuity. (10)
Memory problems and issues with brain development:
Folate deficiency during pregnancy can lead to memory problems and developmental issues in children. Adequate folic acid is crucial for brain development and memory function from utero onward. Deficiency also impacts cognitive health in aging populations, contributing to conditions like dementia and Alzheimer’s.
Research Support:
Studies involving both animals and humans have suggested that there is a link between intake of folate in mothers and brain development in fetal and child growth. One study revealed low maternal folate levels affecting short-term memory in 3-week-old mice, suggesting that child memory problems can be impacted by folate deficiency. Additionally, folate has been studied in its impact on the aging population, and research has suggested that folate deficiency sometimes leads to reversible dementia and also increases the risk of Alzheimer's disease and vascular dementia. This is possibly due to methylation related processes or homocysteine mediated vascular or neurotoxic mechanisms. (11)(12)
Additional symptoms:
Headache, dizziness, paleness, and shortness of breath are symptoms of anemia linked to folate deficiency. Doctors typically test for folate and B12 deficiencies when treating anemia, so it's important to seek medical attention for these symptoms to rule out a deficiency. (8)
How Much Vitamin B9 Should Your Child Have per day?
Research shows adolescent females, especially those menstruating or sexually active, are at greater risk for insufficient folate intake. Adequate folic acid before conception prevents birth defects like spina bifida and is crucial during pregnancy to prevent neural tube defects. Pregnant individuals should take 600-800 mcg of folic acid daily. (13)
Daily folic acid intake is recommended based on individual needs. Consult a physician to determine the appropriate routine for your child's specific requirements. (14)
| Age |
RDAs* (males and females) in micrograms (mcg) |
| Birth to 6 months |
65 mcg DFE** |
| 7-12 months |
80 mcg DFE |
| 1-3 years |
150 mcg DFE |
| 4-8 years |
200 mcg DFE |
| 9-13 years |
300 mcg DFE |
| 14-18 years |
400 mcg DFE |
| 19+ years |
400 mcg DFE |
*RDAs = Recommended Dietary Allowances
**DFE= Daily Folate Equivalent
- 1 mcg DFE = 1 mcg food folate
- 1 mcg DFE = 0.6 mcg folic acid from fortified foods or dietary supplements consumed with foods
- 1 mcg DFE = 0.5 mcg folic acid from dietary supplements taken on an empty stomach
Should you Give Your Child Vitamin B9 Supplements?
Children typically get enough vitamin B9 from a varied diet, but deficiency may occur due to poor diet, illness, or excessive urination. Increase folate-rich foods like leafy greens (spinach, lettuce) or consider supplements for picky eaters or suspected deficiencies.
Foods That are Rich in Vitamin B9
A balanced diet diverse in foods can provide children with adequate amounts of vitamin B9. One can achieve the recommended folic acid intake in the form of fruits and vegetables, meat and meat products, dairy, seafood and nuts and seeds. Examples of folic acid and folate in food are listed below.
Selected food sources of folate and folic acid are listed below. (14)
| Food Name |
Serving size |
DFE per serving in micrograms (mcg) |
% Daily value (DV) |
| Beef liver, braised |
3 oz |
215 |
54 |
| Spinach, boiled |
1/2 cup |
131 |
33 |
| Black-eyed peas, boiled |
1/2 cup |
105 |
26 |
| Fortified breakfast cereals |
1/2-1 cup |
100 |
25 |
| White rice, cooked |
1/2 cup |
90 |
22 |
| Asparagus, boiled |
4 spears |
89 |
22 |
| Brussels sprout, boiled |
1/2 cup |
78 |
20 |
| Spaghetti, cooked, enriched |
1/2 cup |
74 |
19 |
| Lettuce, romaine |
1 cup |
64 |
16 |
| Avocado, raw |
1/2 cup |
59 |
15 |
|
Spinach, raw
|
1 cup |
58 |
15 |
Can too Much Folate be Harmful?
The upper limit for folic acid is 1,000 mcg daily. Exceeding this can cause side effects, including a vitamin B12 deficiency, especially in adults with vegetarian diets.
Folic acid and vitamin B12 are both vital for red blood cell production, and a deficiency in either can cause iron deficiency. High folic acid intake can mask B12 deficiency, leading to irreversible brain and nerve damage. To avoid this, it's recommended to keep folic acid intake under 400 mcg daily, accounting for folate from food sources and fortified products. (5)
What happens if you have too much vitamin B9? Folic acid is unsafe when taken by mouth in enormous portions. Although amounts of up to 5 mg per day have been safely administered in past research, taking folic acid in excess of 1 mg per day may cause uncomfortable side effects including: (5)(2)
- Stomach cramps
- Diarrhea
- Skin irritation
- Restlessness and sleep issues
- Irritability
- Disarray
- Stomach upset
- Vomiting
- Behavior changes
- Seizures
- Gas
- Sensitivity
- Excitability
Summary
Folate is a vital water-soluble vitamin that supports health at all ages. It is crucial for preventing neural tube defects in infants and treating folate deficiency and high homocysteine levels. Research shows folate also aids in depression, cognitive development, cancer prevention, heart disease prevention, and lowering blood sugar levels.
Recent evidence challenges current food fortification strategies, prompting a review of approaches. Alternative methods, such as bio-fortified foods and stabilized folate forms, are emerging. Vitamin B9 is available from both natural food sources and supplements.
Food sources of folate include naturally occurring folate in dark leafy greens and citrus fruits, and folic acid in fortified grains. Those with conditions affecting folate absorption or excessive urination may benefit from supplementation. Folic acid can also aid conditions like vitiligo and kidney issues. Consultation with a physician is advised, especially for picky eaters with limited diets.
References
- https://pubmed.ncbi.nlm.nih.gov/29477222
- https://www.hsph.harvard.edu
- https://pubmed.ncbi.nlm.nih.gov/24298825
- https://www.ncbi.nlm.nih.gov/PMC3982215
- https://www.webmd.com/vitamins
- https://journals.sagepub.com
- https://pubmed.ncbi.nlm.nih.gov/29501221
- https://www.nhs.uk/conditions
- https://www.sciencedaily.com/releases
- https://pubmed.ncbi.nlm.nih.gov/30919078
- https://www.ncbi.nlm.nih.gov/PMC6520042
- https://www.ncbi.nlm.nih.gov/PMC1123448
- https://www.ars.usda.gov/80400530
- https://ods.od.nih.gov/factsheets/Folate
Disclaimer: The content of this blog post is intended for informational purposes only. It is not intended as a substitute for professional medical advice, diagnosis, or treatment. You should not use this information for diagnosing or treating a health problem or disease, or prescribing any medication or other treatment. Always seek the advice of your physician or other qualified health provider before taking any medication or nutritional, herbal or homeopathic supplement and with any questions you may have regarding a medical condition.
