Vitamin B9 – which is called folate when it comes from food, and folic acid when it is provided by a food supplement – is an essential vitamin for the immune system. It is essential for the production of red blood cells and for the proper functioning of the central nervous system.
It is found in good amounts in organ meats (liver), leafy green vegetables, legumes and some fruits and nuts. But it is a fragile vitamin, which disappears during cooking and freezing. And B9 requirements may be increased, requiring supplementation.
Some special cases
In case of pregnancyall pregnant women must be supplemented with folic acid throughout their pregnancy to prevent their fetus from developing a serious neural tube defect (Spina Bifida).
In case of consumption of alcohol or certain drugssome substances interfere with folate metabolism.
In case of proven deficiency, the main signs of a deficiency are: fatigue, memory and concentration disorders, digestive disorders and headaches. Folate deficiency can be diagnosed with a simple blood test. Studies have linked low blood levels of folate to an increased risk of dementia. But folic acid supplementation has not been proven to prevent dementia or improve cognitive function.
For the prevention of other diseases: Folate supplementation would reduce the risk of stroke, as well as the risk of developing breast cancer or colon cancer.
Beware of excess
An excess of folic acid can lead to neurological (sleep disturbances, irritability) or digestive (abdominal cramps, diarrhoea) disorders. A maximum daily dose is fixed, it is 1000 µg (micrograms). Elderly people and vegans should limit themselves to 400 mcg per day, because vitamin B9 can mask a vitamin B12 deficiency, which can irreversibly damage their brain and nervous system. It is better to ask your doctor for advice.
Source: Harvard University School of Public Health.
