Vitamin B9 (Folic Acid/Folate): Essential for Cellular Health, Cardiovascular System, and Fetal Development

This member of the B-complex is a key player in cell growth, blood formation, and nervous system health—making it indispensable at every stage of life, but especially for women planning a pregnancy or already expecting.

In this article, you will learn why vitamin B9 is so vital for your health, what consequences a deficiency may have, and how to ensure optimal supply through diet or supplementation.

What Is Vitamin B9 and Why Is It So Important?¹ ²

Vitamin B9, also known as folate (natural form) or folic acid (synthetic form), belongs to the water-soluble B vitamins and is essential for numerous processes in the body. Unlike many other vitamins, it is not stored for long periods—regular intake is therefore crucial.

Key Functions at a glance:

·       Cell Division and DNA Synthesis: Healthy cell regeneration is impossible without folate.

·       Blood Formation: Folate supports the production of red blood cells and helps prevent anemia.

·       Nervous System: Together with B6 and B12, B9 regulates homocysteine levels—an important factor for brain and vascular health.

·       Cardiovascular Protection: Adequate folate levels help prevent vascular damage and cardiovascular disease.

·       Pregnancy: Sufficient folate is essential to reduce the risk of neural tube defects in the unborn child.

Signs and Causes of Vitamin B9 Deficiency³

A deficiency can develop gradually and often presents with nonspecific symptoms. Those particularly at risk include pregnant women, people with unbalanced diets, seniors, and individuals with high alcohol or medication use.

Typical signs:

• Persistent fatigue, concentration problems 
• Depressive moods
• Digestive disorders
• Burning tongue
• Shortness of breath

Possible causes:

•  Diet low in folate (e.g., diets high in processed foods)

• Increased demand during pregnancy, breastfeeding, and growth phases

• Alcohol abuse

• Medications such as antiepileptics or certain contraceptives

• Chronic diseases (e.g., intestinal disorders with malabsorption)

Medical Applications of Vitamin B9

Hence, folate plays an important therapeutic role in several areas:

·       Pregnancy and conception: The best-known use is supplementation before and during pregnancy. Starting as early as conception planning, a daily intake of 400 µg folic acid is recommended to significantly reduce the risk of neural tube defects (Blencowe et al., 2010).

 
·       Neurological health: Folate deficiency is linked to cognitive impairment and depression. Especially in older adults, adequate intake may help slow cognitive decline (Walker et al., 2012).

 ·       Cardiovascular prevention: Studies show that sufficient folate intake can lower homocysteine levels—a risk factor for atherosclerosis and stroke (Bazzano et al., 2006).

 ·       Cancer therapy: There is extensive evidence in oncology describing the role of folic acid (folate) in connection with antifolates such as methotrexate.

Methotrexate, a cytostatic agent (anticancer drug) and immunosuppressant, has been used for decades. It inhibits dihydrofolate reductase and thereby blocks folate-dependent DNA synthesis—a classical mechanism in cancer therapy (Chabner et al., 2005).

To protect healthy cells, folinate (5-formyltetrahydrofolate, also known as leucovorin) is administered after high-dose methotrexate therapy. This "rescue therapy" is standard in oncology (Hanood; Mittal, 2025).

Targeted supplementation may also be useful in cases of elevated homocysteine levels or certain chronic diseases, such as:

·       Chronic kidney disease (Refsum et al., 2004)

·       Chronic intestinal diseases such as Crohn’s disease, celiac disease (Khan, Jialal, 2023)

 ·       Liver diseases such as hepatitis, cirrhosis (Medici, Halsted, 2013)

 ·       Cardiovascular diseases such as arteriosclerosis, coronary artery disease (Bazzano et al., 2006)

Requirements and Good Sources of Vitamin B9⁴

The German Nutrition Society (DGE) recommends a daily intake of approx. 300 µg folate for adults.

Pregnant women have a significantly increased requirement of 550 µg/day.

Breastfeeding women need about 450 µg/day.

For children up to the age of 3 years, the recommended intake is 120 µg/day, for children between 10 and 13 years about 240 µg/day.

The DGE refers to folate equivalents, since natural folate from food and synthetic folic acid from supplements are absorbed differently. To allow better comparison, both are expressed in a common unit.

Foods Rich in Folate⁵

Some exemples (often green in color):

·       Lima beans: 360 µg/100 g

·      Chickpeas: 340 µg/100 g

·       Soybeans: 210 µg/100 g

·      White beans: 187 µg/100 g

·       Lentils: 168 µg/100 g

·      Peas: 151 µg/100 g

·      Lamb’s lettuce: 145 µg/100 g

·      Spinach: 145 µg/100 g

·      Broccoli: 111 µg/100 g

·      Asparagus: 108 µg/100 g

·      Leek: 103 µg/100 g

·      Savoy cabbage: 90 µg/100 g

·      Beetroot: 83 µg/100 g

·      Lettuce: 75 µg/100 g

·      Kohlrabi: 70 µg/100 g

·      Bell pepper: 60 µg/100 g

·      Carrots: 55 µg/100 g

·      Tomatoes: 44.5 µg/100 g

·      Honeydew melon: 30 µg/100 g

·      Wholegrain bread: 14 µg/100 g Feldsalat: 145 µg/100 g

Notes on Taking Vitamin B9 Supplements⁶ ⁷

Folic acid supplements are often available as single preparations or as part of B-complex formulas.

For women wishing to conceive, supplementation is standard—ideally starting at least four weeks before conception.

FAQ – Frequently Asked Questions About Vitamin B9

1. Is folate the same as folic acid?

No, as mentioned before, folate refers to the natural form found in food, while folic acid is the synthetic form in supplements or fortified foods. Both act similarly in the body, but folic acid is often absorbed more efficiently.

2. Can diet alone provide enough vitamin B9?

A balanced diet rich in vegetables, legumes, and whole grains can often meet requirements. However, during pregnancy and breastfeeding, diet alone is usually insufficient—supplementation is essential.

3. Can vitamin B9 cause side effects?

No, not at typical doses. Very high amounts, however, can mask a vitamin B12 deficiency. For this reason, monitoring both vitamins is important.

4. Why is vitamin B9 particularly important for women?

Because it not only supports fertility but also ensures healthy fetal development and can positively influence PMS symptoms via homocysteine regulation.

Vitamin B9: A Vitamin for Life

Whether for cell division, nervous system health, or healthy development during pregnancy – vitamin B9 is indispensable. Women in particular benefit from adequate supply, but it is also a key nutrient for the heart and brain. Targeted supplementation can make a decisive difference.

For more information, feel free to read our other blog articles—also on B vitamins—and visit our online shop. There you will also find the volumes of our Codex Humanus and the Medizinskandale series, where B vitamins are also discussed.

Sources:

·       ¹ ² ⁶       https://ods.od.nih.gov/factsheets/Folate-HealthProfessional/

·       ³       https://www.ncbi.nlm.nih.gov/books/NBK535377/

·       ⁴ ⁷       https://www.dge.de/wissenschaft/referenzwerte/folat/

·       ⁵       https://www.vitalstoff-lexikon.de/Vitamin-B-Komplex/Folsaeure-Folat/Lebensmittel

·       Blencowe, H. et al. (2010): “Folic acid to reduce neonatal mortality from neural tube disorders.” International Journal of Epidemiology.

·       Bazzano, L. A. et al. (2006): “Effect of folic acid supplementation on risk of cardiovascular diseases: a meta-analysis of randomized controlled trials,” JAMA.

·       Walker, J. G. et al. (2012): “Oral folic acid and vitamin B-12 supplementation to prevent cognitive decline in community-dwelling older adults with depressive symptoms—A randomized controlled trial,” Am J Clin Nutr.

·       Chabner, B. A. et al. (2005): “Timeline: Chemotherapy and the War on Cancer,” Nat Rev Cancer.

·       Hanoodi, M.; Mittal, M. (2025, laufend aktualisiert): “Methotrexate,” StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing.

·       Refsum, H. et al. (2004): “Facts and recommendations about total homocysteine: an expert opinion,” Clin Chemistry.

·       Khan, K. M.; Jialal, I. (2023, laufend aktualisiert): “Folic Acid (Folate) Deficiency,” StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing.

·       Medici, V.; Halsted, C. H. (2013): “Folate, alcohol, and liver disease,” Mol Nutr Food Res.

·       Bazzano et al. (2006): “Effect of folic acid supplementation on risk of cardiovascular diseases: a meta-analysis of randomized controlled trials,” JAMA.