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An essential B vitamin, folate—called folic acid in supplements—deserves special attention because a shortfall can contribute to serious health problems, including heart disease, stroke, and neural tube defects in babies. Lack of folate can also lead to megaloblastic anemia, a condition characterized by abnormally low numbers of red blood cells that become enlarged, with symptoms that include lack of energy, irritability, and trouble concentrating.
Studies have also found possible links between low folate levels and increased risk for depression, cognitive difficulties, Alzheimer’s disease and other types of dementia, preterm births, and possibly cancer.
For decades, folic acid supplementation has been emphasized for women to prevent birth defects in their children, and such tragedies have been reduced. But older people are also at risk of deficiency because of poor diet, poor digestion, or other health conditions.
Folate and vitamin B work together to make red blood cells, prevent anemia, and perform other vital functions. An Australian study of 900 people between the ages of 60 and 74 found that supplementing daily with 400 mcg of folic acid and 100 mcg of B reduced mental distress and improved memory. In addition, taking a B-complex supplement can provide other essential B vitamins that work together.
What Causes Folate Deficiency?
A diet that’s low in folate is one obvious cause. Others include alcoholism, poor nutrient absorption due to digestive diseases or age, and medications that deplete folate.
A mutation to the MTHFR (methylenetetrahydrofolate reductase) gene that prevents the nutrient from being converted into an active form in the body can also be a culprit. It’s estimated that this genetic mutation occurs in about 10 percent of Caucasians and Asians, 25 percent of Hispanics, and 1 percent of African Americans. Although not all experts agree about its importance, studies show that the active form of a folate supplement—5-MTHF—can overcome the genetic problem and compensate for poor absorption.
Drugs that deplete folate include metformin for type 2 diabetes, methotrexate for rheumatoid arthritis, and some diuretics and antiseizure drugs. Medically supervised supplementation with folic acid can reduce the harmful side effects.
Different Forms of Folate
Folate is the form of vitamin B found in food. Beef liver and leafy greens are the most plentiful natural sources. Many supplements use synthetic forms of the vitamin, including:
- Folic Acid: Found in many multivitamins and other supplements, folic acid is also added to breakfast cereals and other grain foods.
- 5-MTHF: In your body, natural folate from food, folic acid from supplements, and folic acid that has been added to foods must all be converted to the active form of the vitamin: 5-MTHF. This form is found in many supplements, listed on labels as 5-MTHF, methylfolate, or methyltetrahydrofolate. Supplements that contain the active form eliminate the conversion step and are moreeasily used by your body.
- Folinic Acid: Another active form of folate, folinic acid is found in some supplements. Research is testing this form in autistic children to see if it improves behavior.
Synthetic vs Natural Folate
Perhaps surprisingly, the synthetic form of vitamin B—folic acid—is better absorbed than the folate found naturally in food. Labels are now required to reflect this, by listing micrograms of dietary folate equivalents (mcg DFE), instead of simply micrograms. The “DFE” represents bioavailability.
Compared to folate from food, you need only half as much folic acid in supplements if it’s taken on an empty stomach, and 60 percent if it’s taken with food. For example, 100 mcg of folate from food would equal 60 mcg DFE of folic acid taken with food, or 50 mcg DFE taken on an empty stomach. No separate measurements have been set for 5-MTHF or folinic acid.
Getting the Right Amount of Folate
On product labels, the simplest approach is to look for the %DV (Percent Daily Value). Teens and adults need 400 mcg DFE daily. Women need 600 mcg DFE when pregnant and 500 mcg DFE when breastfeeding.
For any woman who could get pregnant, it’s important to get the daily requirement of folic acid (400 mcg DFE), because a shortfall at the time of conception increases risk for birth defects—and not all pregnancies are planned.
The safe upper limit for any form of folic acid from supplements and fortified foods is about 1,700 mcg DFE daily (1,000 mcg). However, higher doses may be recommended by health professionals in specific, supervised situations.
If you have older (but not expired) supplements that list dosages in mcg, multiply the amount of folic acid by 1.7 to get the amount in mcg DFE.