Folic acid is a supplement used to address a very wide range of problems, but is particularly well known for preventing birth defects. Folic acid is also known as folate, or vitamin B9, though technically folic acid is a synthetic version.

Over 70 countries require folic acid supplementation to be included in some foods, usually wheat, and/or other grains and cereals. Nearly all countries recommend additional supplementation if trying to become pregnant, pregnant, or breastfeeding. Despite this, a significant number of individuals are folic acid deficient.

Folic acid produces no known side effects when used at recommended levels. It's unclear if it's unsafe to take very large amounts---over 1000 mcg per day---over a long period of time.

Use in Pregnancy & Breastfeeding

Folate is critical in pregnancy, particularly the first trimester. Many medical authorities recommend women take folic acid supplements for a year before becoming pregnant, continuing through the first trimester. The vitamin is responsible for a number of functions, most importantly in pregnancy:

• Protects and repairs RNA and DNA
• Aids rapid cell division and growth
• Prevents development of congenital deformities in the brain or spine

Folic acid and its effects on birth defects are very well studied; it's quite clear that it plays a significant role in preventing certain deformities. Specifically, in the 3rd week of pregnancy, the neural tube, which eventually turns into the spinal column and brain, starts to develop. If folic acid levels are too low, neural tube defects (NTD) may occur when the neural tube does not close correctly, causing spinal or brain deformities which can range from unsightly and uncomfortable to fatal. Most common are:

• Spina bifida
• Anencephaly
• Hydranencephaly
• Encephalocele
• Iniencephaly

Note that folate deficiency is not the only cause of NTDs, but it is among the more common of the causes. Patients taking folic acid see a reduction of around 30% to 70% of such NTDs, depending on diet and the amount of other folic acid supplementation in the patient's area. There's also around a 30% reduction in congenital heart defects.

Other effects are less clear. There are conflicting studies as to folic acid reducing rates of autism, severe language delays, and emotional problems in children exposed to adequate levels during pregnancy; some studies notice no difference, while other say cognitive issues are reduced.

Because of the variation in diet it's difficult to quantify how much needs to be supplemented:

• Patients with a good diet relatively high in folic acid are often advised to take 400 mcg (0.4 mg) per day.
• Those with a poor diet in relation to folic acid may be advised to take 4 mg per day.
• Individuals who have a history of pregnancy with NTD complications may be advised to take more than 4 mg per day, though this is relatively unusual.
• Women who are breastfeeding are usually advised to take 400 to 500 mcg (0.4 to 0.5 mg) per day, though it might be as high as 1000 mcg (1 mg) per day in some cases.

Vitamin b12 is also important in preventing birth defects and promoting a healthy baby.

Other Uses

Folic acid isn't just for pregnant women; the vitamin is important in all ages. It can be used to help prevent or treat:

• Heart disease
• Stroke
• Depression
• Certain cancers
• Age-related hearing loss
• Age-related macular degeneration
• Fertility in men and women

Note that while folic acid does provide benefit in some cancers, it can be detrimental in others.

General folate deficiency is more common, which produces fairly vague symptoms of:

• Fatigue
• Weakness
• Irritability
• Depression
• Impaired memory
• Cognitive difficulties
• Loss of appetite
• Sores in/around the mouth

The ideal dosage in treating any of these conditions can be quite variable, depending on their severity, folic acid deficiency, country standards, and other factors. Supplementation of up to 1000 mcg (1 mg) per day even over the very long term is considered harmless, and it's disputed as to the potential dangers of long-term use at higher amounts.

Natural Sources

Folate is found in a wide variety of foods. Those who wish to eat a more folate-friendly diet may want to consume more of the following:

• Dark leafy greens
• Asparagus
• Turnips
• Beets
• Most types of beans
• Salmon
• Beef liver
• Avocado
• Root vegetables
• Orange juice
• Brussels sprouts
• Spinach
• Brewer's yeast

Again in many countries it's also added to bread, grains and cereals. Supplementation will likely still be needed in women who are pregnant or nursing, or those individuals suffering folate deficiency.