Folic acid is sometimes classed as vitamin B9 or vitamin M. It is essential for the basic functioning of the nucleus in cells, and extra amounts may be needed during pregnancy, breast feeding, and in the treatment of anaemia and alcoholism. It assists in the uptake and utilisation of iron. During pregnancy, supplements may prevent spinal cord defects in the baby. It is found naturally in liver, dark green leafy vegetables, peanuts, beans, whole grain wheat and yeast.
The level in blood can be measured and the normal range is 9.1 to 57 nmol/L (4 to 25 ng/mL). The amount in red blood cells can also be measured (normal range is a level greater than 318 nmol/L or 140 ng/mL), which gives a longer term picture than the normal folic acid level in blood which may be affected by recent changes in diet.
Low levels can be due to long-term alcoholism, oral contraceptive use, anticonvulsant medications, malnutrition, sprue (poor food absorption), sickle cell anaemia, cytotoxic drugs (used to treat cancer), pregnancy and food malabsorption syndromes.
On the other hand, a low intake in the diet can cause pernicious anaemia.