Folate is found in a wide range of foods including vegetables, legumes, eggs, and fruit. It is also known as vitamin B-9.
Apart from beef liver, meat is generally low in folate. Many foods are also fortified with synthetic folate, or folic acid.
Adequate folate intake is extremely important during periods of rapid growth such as pregnancy, infancy, and adolescence.
This article provides an in-depth look at recommended intake of folate, its possible health benefits, foods high in folate and any potential health risks of consuming folate.
The recommended daily allowance (RDA) of folate is different for people of different ages, as follows:
- 0 to 6 months: 65 mcg
- 7 to 12 months: 80 mcg
- 1 to 3 years: 150 mcg
- 4 to 8 years: 200 mcg
- 9 to 13 years: 300 mcg
- ver 14 years: 400 mcg
- during pregnancy: 600 mcg
- during lactation: 500 mcg
Recommended folate intake increases during pregnancy and breastfeeding to fuel rapid growth and help prevent neural tube defects in the fetus.
The most common causes of folate deficiency include an inadequate diet, alcoholism, and difficulties in absorbing foods that contain folate or folate itself.
In addition, the body requires the conversion of folic acid to its active form, methylfolate. Genetics can occasionally get in the way of this conversion, which can lead to a folate deficiency.
Taking a supplement in the active, or reduced, form of L-methylfolate (5-MTHF) may help to make sure that the body is receiving folate in the most useful way. Speak to your doctor about individual needs and if a certain supplement is needed.
Folic acid supplements play an important role in ensuring that vulnerable individuals and those in greater need of folate receive enough. Increasing intake of folate-rich foods is also important as these foods typically also provide plenty of other nutrients that all act together to support good health.
Anyone who may become pregnant is recommended to obtain 400 micrograms (mcg) per day of folic acid from dietary supplements in addition to the folate present in a varied diet.
Decreased risk of congenital deformities
It is essential to consume enough folic acid during pregnancy to help protect against miscarriage and neural tube defects in the fetus.
Recent research has also shown that a father's folate status before conception may be just as important.
In a study from McGill University, paternal folate deficiency in mice was associated with a 30 percent increase in various congenital deformities than in offspring with no paternal folate deficiencies.
Lower risk of depression
Folic acid supplementation has not been suggested as a treatment in itself for depression, but it may be helpful in improving response to antidepressants such as fluoxetine, especially in women.
Maintaining a healthy heart
Folic acid supplements have been found to lower levels of homocysteine.
As elevated levels of homocysteine are associated with an increased risk of cardiovascular disease, some researchers have suggested that folic acid and B12 may reduce the risk of cardiovascular disease.
Folate and cancer
Low levels of folate intake are associated with an increased risk of breast cancer in women and several epidemiological studies have suggested an inverse association between folate status and the risk of colorectal, lung, pancreatic, esophageal, stomach, cervical, ovarian and other cancers.7,8
One study, for example, suggested that folate can have protective effects against esophageal cancer.
However, other studies have found no association between folate and cancer.
Some studies even suggest that high folate status might promote progression of cancer that is already present, such as a study in rats that showed how supplementation can cause tumor growth.
When taken long before colorectal cancer is diagnosed, high folate intake is associated with a lower risk of colorectal cancer.
However, it should be noted that taking folic acid supplements once precancerous lesions develop did not appear to lower the risk of colorectal cancer in this study.
The ability of the body to absorb, use, and retain folate varies between among foods and is difficult to measure.
There are 150 different forms of folate, and losses of between 50 and 90 percent can occur during cooking, storing, or processing. The best sources of folate are green vegetables, legumes, and liver.
One cup of some of the best natural food sources of folate contains the following amounts:
- Asparagus: 268 mcg
- Beef liver: 290 mcg
- Lentils: 920 mcg
- Beans: 784 mcg
- Spinach: 58 mcg
- Lettuce: 14 mcg
- Avocado: 118 mcg
- Egg yolk: 355 mcg
- Banana: 45 mcg
- Mushrooms: 16 mcg
- Broccoli: 28 mcg
In 1998, the United States Food and Drug Administration (FDA) and the Canadian government began requiring that manufacturers add folic acid to certain foods, including enriched bread, cereals, flours, cornmeal, pasta, rice, and other grain products.
The typical diet in the U.S. contains a large amount of these foods, making fortified products an important contributor to the overall folic acid intake. Other countries that require fortification of certain foods with folic acid include Costa Rica, Chile, and South Africa.
High levels of intravenous folic acid intake may cause seizures, and high doses of supplemental folic acid have been associated with an increased risk of the progression of certain cancers.
Dietary levels of folate have not, however, been associated with any adverse effects.
An intake of folate above 1000 mcg for adults or 800 mcg for those aged 18 years or under can hide a deficiency of vitamin B12. Vitamin B12 deficiency can cause permanent nerve damage and paralysis.
Folate is only beneficial as part of a wide-ranging, varied, and nutritious diet.