Vitamin B9 is a water-soluble vitamin also known as folic acid or folate. It plays an important role in cell division, DNA synthesis and amino acid metabolism. Vitamin B9 is essential for the healthy functioning of the brain, nervous system and blood formation.
Folic acid is the synthetic form of vitamin B9 found in supplements and fortified foods such as flour, bread, and breakfast cereals. Folic acid is more easily absorbed by the body than naturally occurring folate compounds.
Folate – natural vitamin B9
Folate is the naturally occurring form of vitamin B9 found in various foods such as green leafy vegetables, legumes, oranges, and liver. It is converted in the digestive tract to its active form, 5-methyltetrahydrofolate (5-MTHF).
So, the biologically active form of vitamin B9, which circulates in the body and is involved in metabolic processes, is called 5-MTHF. It is also found in some supplements and can be an alternative for people who have difficulty converting folic acid into its active form.
Vitamin B9 deficiency
Vitamin B9 deficiency can lead to various health problems, such as anemia, fatigue, weakness, memory problems, and birth defects in newborns. Pregnant women have an increased need for vitamin B9 to reduce the risk of neural tube defects in the baby.
Vitamin B9 daily requirement
The recommended daily allowance (RDA) for vitamin B9 varies depending on age, gender, and life stage. For adult men and women, the average RDA is 300 micrograms. For pregnant women and for breastfeeding women, the RDA will be set higher.
Sources of vitamin B9
Good food sources of vitamin B9 include green leafy vegetables (e.g., spinach, kale), legumes (e.g., lentils, chickpeas), nuts and seeds, fortified grains, oranges, and liver. A varied diet can meet the daily requirement of vitamin B9.
Folic acid overdose
An overdose of vitamin B9 (folic acid or folate) is rare because it is water-soluble. Excess amounts are usually excreted in the urine. Nevertheless, excessive intake of folic acid, especially through supplements, can lead to undesirable side effects. Typical for a folic acid overdose are, for example:
- Gastrointestinal complaints
Long-term excessive intake of folic acid can also cause vitamin B12 deficiency to go undetected, as folic acid can mask the anemia symptoms usually associated with vitamin B12 deficiency. This can be particularly problematic in the elderly, as an undetected vitamin B12 deficiency can lead to permanent nerve damage.
To minimize the risk of overdose, you should stick to the recommended daily doses and pay attention to the dosage, especially when taking vitamin B9 supplements. Also, talk to your doctor or dietitian before taking any supplements.