Function

Folic acid is essential for the creation of new body proteins, which is what we are all made up of, through the synthesis of DNA. If the body is deficient in folic acid anaemia can develop. This is an easily recognized type of anaemia in which there is a shortage of red blood cells and those which are produced are larger than average (megaloblastic anaemia).

Requirements

The RNI (reference nutrient intake) for folate for adult women was set at 200 mcg per day.

Sources

Rich food sources of folate include yeast extract (Marmite), meat extract (Bovril), black-eyed beans, leafy green vegetables and orange juice. Unfortunately, inappropriate food preparation and cooking can reduce the folate content of foods. Some breads and breakfast cereals are fortified with folic acid, so check the labelling. See our recipe section for some folate rich recipes.

Examples

• Bran Flakes 45g 113 mcg
• Granary Bread 75g (2 large slices) 68 mcg
• Sprouts 115g 127 mcg
• Broccoli 95g 61 mcg
• Orange 245g (1 large) 54 mcg
• Black-eye Beans 105g 220 mcg
• Cottage Cheese 150g 40 mcg
• Marmite 5g 50 mcg

Interactions

Megaloblastic anaemia can also be caused by a lack of vitamin B12. However vitamin B12 is found in nearly all animal tissues therefore only people consuming a vegetarian or vegan diet are at risk of deficiency. Although vitamin B12 is only found in animal tissue many products are fortified with B12, including breakfast cereals.

Pregnancy Functions and Requirements

The RNI for folate for adult women was set at 200 mcg per day, with an increase during pregnancy of 100 mcg per day set by the Department of Health in 1991. However, recent research has found that the incidence of neural tube defects such as spina bifida can be reduced if women increase their folate intake above these levels before conception and during the first three months of pregnancy. It is now recommended that in this period folic acid supplements are taken (400 mcg per day) and dietary intake is increased to 300 mcg per day. The RNI for folate whilst breastfeeding is 260 mcg per day.

Should I be taking a high or low dose of folic acid supplements?

You only need to take a high dose, i.e. 5mg, of folic acid if:

• If you or your partner has an neural tube defect (NTD)
• You have had a previous pregnancy affected by an NTD
• You have coeliac disease or are a diagnosed diabetic
• You have sickle cell anaemia
• You are taking anti epileptic drugs

If you do not fall into any of these categories you have a low risk for an NTD and so should take 400mcg of folic acid daily. This is advised pre-conceptually and you should continue until the 12th week of pregnancy.