Vitamin B9 is a water soluble vitamin, also known as folic acid, folate and folacin. It is found in the food sources cantaloupe melon, apricots, rye, green leafy vegetables, beans, liver and eggs. The Recommended Daily Amount (RDA) for both males and females in the UK is 400mcg.
Folic acid is well known for its importance in pregnancy, for the prevention of birth defects however it has many other roles including those relating to cardiovascular health, cognitive function, immunity, energy production and the health of the skin. Folate contributes to normal homocysteine metabolism, the normal function of the immune system and contributes to the reduction of tiredness and fatigue.
A deficiency is usually associated with poor diet, alcoholism, and malabsorptive disorders. Symptoms include weakness, fatigue, difficulty concentrating, irritability, headache, heart palpitations, and shortness of breath. Other symptoms include sores in the mouth and on the tongue, changes in skin, hair or fingernail pigmentation and digestive complaints. Women with inadequate intakes of folate are at increased risk of giving birth to infants with neural tube defects. Inadequate maternal folate status has also been associated with low infant birth weight, preterm delivery, and foetal growth retardation.
Prevention of neural tube defects-Neural tube defects are birth defects affecting the brain, spine or spinal cord in pregnancy. These defects are the most common congenital malformations of the central nervous system resulting from the failure of the neural tube to close (1). Low intake of folate in the mother is a risk factor in the development of neural tube defects in the developing foetus (2). Folic acid has been shown to have a protective effect against neural tube defects in the foetus by way of increasing the amount of folate available in the red blood cells (2). Folate which is detectable in serum or blood plasma can be an indication of early changes to the foetus (3).
Cardiovascular Health-Folate alongside other B vitamins are known to be involved in the processing of homocysteine, a type of protein found in the blood. High levels of homocysteine is associated with an increased risk of cardiovascular disease (4) (5). The Heart Outcomes Prevention Evaluation (HOPE) 2 study involving 5,522 patients aged 55 years or older with vascular disease received either supplementation with folic acid plus vitamin B6 or placebo for approximately 5 years. The results of the study showed a significant reduction in homocysteine levels in those taking the supplements compared to placebo. The same study showed those taking the supplements had a significant reduction in risk of stroke (6). The Women’s Antioxidant and Folic Acid Cardiovascular Study in the U.S evaluating those with a high risk of cardiovascular disease revealed those who took folic acid combined with vitamin B6 and B12 had lowered homocysteine levels (7).
Cognitive Function- Research has shown a link between low folate levels and decline in cognitive function, specifically an increased risk of dementia and Alzheimer’s disease (8), (9), (10) and depression (11). An Australian study involving 900 adults aged between 60 to 74 with depressive symptoms showed that supplementing with 400mcg plus 100mcg vitamin B12 over a period of two years improved cognitive function, particularly in relation to memory (12). A study of 2,948 people in the U.S aged 1 to 39 years showed folate concentrations were lower in those with major depression compared to those who had never experienced depression (13).
Depression- Folic acid supplementation has been suggested to be a potential treatment alongside, but not necessarily instead of, antidepressant medications as supported by the authors of the Cochrane Review group, 2003 (14) and Coppen et al, 2005 (15). A trial in the UK involving 127 patients with major depression received either supplementation with folic acid alongside antidepressant medication or placebo with antidepressants. The results revealed those who received the folic acid plus antidepressant medication experienced a significantly greater improvement in depressive symptoms compared to the placebo plus medication group (11).
Foetal Development-Folic acid supplementation has been shown to lower the risk of preterm birth (16). Research also suggests that the risk of congenital heart defects is reduced when folic acid is combined with a multivitamin supplement (17), (18). In separate studies in both Atlanta and California it was found that congenital heart defects are substantially lower in infants of women who took multivitamins containing folic acid in the period prior to conception compared to the infants of women who did not take supplements containing Folic acid (19). Furthermore, studies have also found a link between the use of folic acid when taken in combination with a multivitamin supplement and reduction in the occurrence of urinary tract abnormalities, facial cleft conditions and limb defects in new-borns (18), (20).
Protecting against birth defects- Supplemental folic acid intake increases maternal folate status. Low maternal folate status is a risk factor in the development of neural tube defects in the developing foetus. Folic acid contributes to maternal tissue growth during pregnancy and has a role in the process of cell division. It is therefore a popular supplement to be taken during pregnancy to help ensure health growth of the baby. Many doctors recommend supplementation however it is advised to discuss this with your GP or midwife.
Recovery from illness- Folic acid contributes to normal function of the immune system. A deficiency may therefore be linked with slow recovery from infection based illnesses. It also contributes to the reduction of tiredness and fatigue which may also help someone recovering to feel better sooner.
Anaemia- Folic acid contributes to normal blood formation. This means that a folic acid deficiency could aggravate anaemia- the result of an iron deficiency. A supplement may therefore help to guard against this.
Muscle growth and function- Folic acid contributes to normal amino acid synthesis. A deficiency could therefore lead to an impairment in the development of healthy muscle tissue. This would make this a popular supplement for those interested in lean muscle gain or those participating in sports.
High intakes of folate have been shown to mask the symptoms of B12 deficiency which can exacerbate symptoms of B12 deficiency if left untreated and therefore it is always recommended to be taken with B12 supplementation. Folic acid is well tolerated. In high doses such as 5-10mg, it has been known to cause increased flatulence, nausea and loss of appetite. Those with epilepsy should take folic acid with precaution as it has been shown to increase seizure activity. The Tolerable Upper Intake Level in the UK has been set at 1,000mcg for both male and females.