Published studies suggest strongly that the incidence of some birth defects such as spina bifida may be related to low folic acid intake. The defects are due to malformation of the neural tube, which develops the baby''s spinal cord in the earliest weeks of pregnancy, often before you even know that you''re pregnant. The government has therefore recommended that for the three months before conceiving and the first 12 weeks of pregnancy women have supplements equivalent to 0.4mg of folic acid per day. If you do not wish to take supplements you can ensure you get adequate amounts in your diet by eating certain foods high in folic acid such as fresh green vegetables. If you have had a pregnancy affected with a neural tube defects, a higher dose equivalent to 5mg folic acid per day is advised.