There are many reasons why women planning to have a baby are advised to take folic acid supplements, rather than just increase their dietary intake of food containing folic acid.
While it is possible for a woman to have adequate intakes of folic acid through her diet, not everyone eats enough foods rich in folic acid on a consistent, daily basis (particularly green, leafy vegetables, which are the richest source). However, women who are vegetarian or vegan usually eat an adequate amount of folic acid in their diet. If a woman drinks alcohol, this interferes with her body's absorption of folic acid. You can read more in alcohol.
Cooking and processing
Heat used in cooking and processing can destroy some of the folic acid naturally available in foods. This will vary depending on the food, and the way it is cooked. In some cases, the loss of folic acid can be as high as up to 50%. For example, folate is present in flour, but may be depleted after being cooked as bread, or after pasta is boiled.
The body does not readily absorb all the folic acid available in natural food sources, when compared to vitamin supplement tablets. It is thought that folic acid taken as supplements is absorbed at 100% of what is eaten, while foods containing natural amounts of folic acid are only absorbed at about 50 to 60%.
Because up to 50% of pregnancies are unplanned, many women will not benefit from taking folic acid supplements. This has brought about a dilemma for health care professionals and governments, aiming to address this issue. One possible suggestion is that ALL women who are sexually active, and of childbearing age (15 to 45 years), should routinely supplement with folic acid 'just in case'. However, this is obviously not a realistic solution.
An alternative solution is to 'fortify' foods. Folic acid 'fortification' essentially means adding folic acid to commercially prepared foods. This is similar to the way iodine is added to salt, or fluoride to water supplies. Countries such as the USA and UK have fortified foods with folic acid for several years. Australia approved voluntary fortification of folic acid by manufacturers for certain foods in 1995. Some foods that are now fortified with folic acid include some brands of flour, bread, savoury cracker biscuits, breakfast cereals, pasta, rice, yeast extracts, fruit and vegetable juices, some soy drinks and tofu.
The nutritional message that may appear on the wrapping of these products in Australia will read:
"A diet rich in the vitamin folate is important for women in their childbearing years. This food is a good source of folate."
Folic acid added to foods is thought to be absorbed by the body at 100%, similar to folic acid supplements.
Related planning for pregnancy articles:
Last revised: Thursday, 13 February 2014
This article contains general information only and is not intended to replace advice from a qualified health professional.