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Mayo Clinic Q and A: Get the Facts Before Taking Folic Acid
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DEAR MAYO CLINIC: Is a folic acid supplement ever recommended for the average person, or just for pregnant women?
ANSWER: Folic acid is the synthetic version (made in a laboratory) of a vitamin B called folate. It’s well-known for its role in helping to prevent birth defects of the brain and spine, which is why it’s often included in fortified foods, such as cereals and pastas. But, folic acid has other influences, as well, such as on your heart and brain health. As you should with any vitamin or mineral supplement, get the facts before you start taking folic acid. In some cases, a supplement may be appropriate, but taking too much folic acid may carry risks.
Folate is found naturally in certain foods. Dark green vegetables, beans, peas and nuts tend to be rich in folate. Folate is important. because it helps ensure a healthy process of creating new cells and plays a part in a variety of normal biochemical activities.
Folic acid is an essential component of prenatal vitamins and typically is included in multivitamin and vitamin B complex supplements. You also can get a supplement of just folic acid. While it’s clear that folic acid supplements are an important means of preventing birth defects, the impact of folic acid is less straightforward on other aspects of health, including:
Vitamin B-12 deficiency — About 10 to 15 percent of older adults don’t get enough vitamin B-12. There may be a number of reasons for this, most commonly due to gastrointestinal absorption issues. Vitamin B-12 deficiency can cause anemia, and brain and nerve problems, such as mental confusion, forgetfulness, and persistent tingling in your hands and feet. Folic acid deficiency can cause the same type of anemia, called macrocytic anemia, but not the neurologic problems. A high intake of folic acid can fix the anemia — even in vitamin B-12 deficiency — but not the neurological issues. Thus, it’s important to make sure vitamin B-12 deficiency is not present before treating a macrocytic anemia with folic acid. If vitamin B-12 deficiency is present, the anemia will improve by taking folic acid, but the neurologic damage will progress and become permanent.
Cardiovascular disease and stroke — One of folate’s main jobs is to break down homocysteine. High levels of homocysteine are associated with an increased risk of cardiovascular disease. Consequently, researchers theorized that reducing homocysteine with folic acid therapy also would reduce cardiovascular risk. But, study results haven’t proved this. Although taking folic acid reduces the level of homocysteine and provides protection against stroke, it doesn’t appear to decrease deaths from heart attack or other cardiovascular causes.
Dementia — High levels of homocysteine have been linked to cognitive decline, an increased risk of Alzheimer’s disease and dementia. Some studies also have linked a low level of folate to dementia. But, other studies haven’t found that taking folic acid improves mental function.
Cancer — A number of epidemiological studies have suggested that getting enough folate, particularly from food sources, reduces the risk of various cancers, including pancreatic, colorectal, cervical, esophageal and other cancers. But, clinical trials studying folic acid supplementation have had mixed results. Some suggest no association. Others suggest an increased incidence of cancer. Researchers say folic acid supplementation may play different roles, depending on when it’s given and in what amount.
Depression — A low level of folate has been associated with depression. Depression can be a difficult disease to treat. Many people with depression aren’t able to get better entirely — even with antidepressant therapy. But, some evidence indicates that treatment with folic acid may be helpful in the long-term management of depression in some people.
The recommended daily amount of folate for adults is 400 micrograms (mcg). Because so many commonly consumed foods in the U.S. are fortified with folic acid, folate deficiency is fairly uncommon. Still, certain groups may need to take supplements, such as pregnant or soon-to-be-pregnant women, people with poor diets, or those with chronic illnesses, such as celiac disease or Crohn’s disease, who may have difficulty absorbing folate and other nutrients. If you have depression, it may be worth talking to your doctor about folic acid as a supplement.
If you’re in good health and your doctor doesn’t think you need a daily supplement, it’s best to get your folate from foods. A balanced diet contains not only the many nutrients found in supplements, but also fiber and other health-promoting substances. If you focus on healthy foods, you’re well on your way to getting the vitamins and minerals you need without a supplement. (adapted from Mayo Clinic Health Letter) — Dr. Donald Hensrud, Preventive Medicine, Mayo Clinic, Rochester, Minnesota
