Women who plan to conceive have long been told they should take extra folic acid to help prevent birth defects. But did you know that supplementing your diet with this form of vitamin B may help protect you from the risks of hypertension and heart disease? “Today” medical contributor Dr. Judith Reichman was invited on the show to discuss why women should take folic acid for their own health, as well as that of their future offspring.
Folic acid is one of the B vitamins. What makes it special?B vitamins all work together to help our body’s metabolism. They are absolutely essential for the functioning of our nervous system, cardiovascular systems and our digestive tract.
Folic acid, also known as folate, is number nine (vitamin B-9) amongst the Bs, but in many ways it’s number one. It’s crucial for the formation and growth of new cells during pregnancy and infancy, especially brain development and function. It helps prevent damage to DNA (and there is some thought that it may be protective against certain cancers), it helps form the iron-containing protein heme in red blood cells, and finally it aids the performance of enzymes that metabolize and break down homocysteine, an amino acid which is harmful to the vascular system.
Can’t we get enough folic acid from food sources?Depending on what we consider enough, it can be difficult. Folic acid is present in citrus fruits, tomatoes, green leafy vegetables, asparagus, broccoli, lentils, beans, eggs, beef and whole grains. Since 1998, it’s been added to flour and cereals. (This enrichment has given the average person a folic acid “boost” of about 200 micrograms a day).
We now know, however, that the naturally occurring folic acid in foods may not be adequate for the majority of individuals. Synthetic folic acid, used for enrichment and in supplements, has twice the biologic availability as naturally occurring folate. (It has a simpler chemical structure and is more easily absorbed.) In other words, it’s twice as likely to raise our body’s folic acid levels and render a positive effect when it’s provided as a supplement.
When should a woman consider taking folic acid and how much?New studies indicate that all of us should consider taking folic acid supplements starting from reproductive age, not just for our future baby’s health, but also for our own well-being. In a recent report from the Nurses Study (a long-term study of the health of thousands of nurses) , published in The Journal of the American Medical Association (JAMA), two groups of women were tracked for more than eight years. The younger group of women (ages 25 to 42) who consumed 1000 micrograms of folic acid through foods and supplements had a 46 percent decrease in their risk of developing hypertension as compared to those women who consumed less than 200 micrograms. In addition, this was not altered by other risk factors, such as their weight, physical activity rates, cholesterol or fat intake. In a second, older group of women (ages 30 to 55) 1000 micrograms of folic acid was found to decrease risk of developing hypertension to a lesser extent — 18 percent.
Most multivitamins usually contain 400 micrograms of folic acid (the current recommended daily allowance). Did they check to see if this was enough to protect the women from hypertension?
Yes they did, but when they compared the 1000 microgram intake to 400 micrograms in the younger group, the researchers found that those who took the higher dose still had a decrease in hypertension of 40 percent, and in the older women, the decrease was 13 percent.
Does folic acid help prevent heart disease?If indeed, as seen in this study, it lowers the risk for hypertension, this alone should reduce the chances of heart attack and stroke. But folic acid has another known heart-health effect: It reduces the level of the “heart-harming” amino acid homocysteine. (This amino acid is formed during the complex metabolism of another amino acid called methionine.)
High levels of homocysteine are toxic to the endothelial cells, which line our blood vessels. Too much homocysteine also causes blood vessels to lose their elasticity and ability to dilate. Calcium, cholesterol and collagen then adhere to the sites of injury and cause the formation of plaque. Add to this blood turbulence caused by the rigid, partially blocked vessels, and conditions are set for a piece of plaque to sheer off, ultimately blocking cardiac vessels (a heart attack) or brain vessels (a stroke). To add insult to injury, high homocysteine levels also promote plaque formation, so individuals with elevated homocysteine may be at increased risk for leg clots and pulmonary embolism.
Women have lower levels of homocysteine before menopause than when they are postmenopausal. We also know that nutritional deficiencies as well as genetic mutations can cause some women to have elevated homocysteine levels. (In other words, this can be inherited.)
How does a person know if she (or he) has a high homocysteine level, and how much folic acid is needed to reduce it?A blood test can be done to check your homocysteine level. If it’s high, your doctor will usually start you on one or two milligrams (1000 to 2000 micrograms) of folic acid, and probably add vitamin B-12, then recheck the homocysteine levels six to eight weeks later. If the supplement has not reduced the level sufficiently, she will slowly increase the folic acid dose up to 10 or even 15 milligrams. (NOTE: This is done through prescription, and your doctor should make sure your vitamin B-12 level is normal. Very rarely, high doses of folic acid can mask an anemia due to B-12 deficiency. If untreated, this can cause neurological problems.)
Will supplementing folic acid help prevent or reduce Alzheimer’s?No. Studies of folic acid with or without B-12 have not demonstrated an effect on either cognition or moods in Alzheimer’s patients or for that matter in healthy individuals, when compared to use of placebos.
How much folic acid do we need if we are pregnant or planning to become pregnant?In order for folic acid to help prevent neural tube defects (a congenital opening along the spine, also known as spina bifida), it must be taken before conception and during the first four weeks of fetal development. The neural tube that becomes the spine and brain is almost completely formed by the time of the first missed period.
Some studies have shown that diet alone is not effective in increasing the blood level of folate sufficiently to decrease risk for neural tube defects (NTDs). Thus, because half of the pregnancies in the U.S. are unplanned, the recommendation in place since 1992 by the U.S. Public Health Service and the American College of Obstetricians and Gynecologists, (ACOG) is that all women capable of becoming pregnant take 400 micrograms of folic acid (the amount in most over-the-counter multivitamin pills). We definitely shouldn't simply rely on the fact that folic acid added to flour and other food gives most of us 200 micrograms. It’s not enough. Since this fortification went into effect, spina bifida has decreased by only 19 percent.
It’s felt that if all women of reproductive age were to take 400 micrograms of folic acid, the incidence of this birth defect would decrease by 36 percent. In addition, estimates are that 4000 micrograms (4 milligrams) a day would decrease spina bifida by 82 percent.
The CDC has recommended that all women who have had a pregnancy complicated by a neural tube defect take 4 milligrams a day of folic acid, and continue this through the first trimester in their next pregnancy.
What do women get with the typical prenatal vitamins?These usually contain 1000 micrograms of folic acid (and a specific prescription is usually required to purchase them). Many doctors recommend that women who may get pregnant start prenatal vitamins before conception. It is not recommended to take a double dose (or more) of regular over-the-counter multivitamins to get the higher folic acid dose — these may contain too much vitamin A, a potential disaster, since doses of A higher than 5000 units can cause birth defects if taken during early pregnancy.
Can we get high-dose folic acid over the counter?As noted, doses of 1000 micrograms or more usually require a prescription. However, you can get the 400 microgram pills; they’re small, and if you take one or two of these and one multivitamin, your total dose (with appropriate diet), will then be at least 1000 micrograms.
Bottom-line, how much folic acid should women take?Once a woman becomes sexually active, she should take a multivitamin. I suggest adding at least 400 micrograms of folic acid. If she is trying to conceive (or is not sure of her contraception) she should talk to her doctor about adding much higher doses, up to 4000 micrograms. If pregnancy is not (or no longer) an option, she should probably maintain a total dose of 1000 micrograms of folic acid. That’s what I do. Actually, I take one multivitamin and a tablet of 400 micrograms folic acid every day.
After menopause, her doctor should check her homocysteine levels, and if it’s high, her B-12 levels should also be checked, and if necessary, B-12 should be supplemented. Increasing doses of folic acid should be prescribed in order to get her homocysteine levels down to normal limits.
Folic acid is a vitamin supplement that, together with good nutrition and exercise, can help us maintain our health and the health of our progeny.
Dr. Judith Reichman, the “Today” show's medical contributor on women's health, has practiced obstetrics and gynecology for more than 20 years. You will find many answers to your questions in her latest book, "Slow Your Clock Down: The Complete Guide to a Healthy, Younger You," which is now available in paperback. It is published by William Morrow, a division of .
PLEASE NOTE: The information in this column should not be construed as providing specific medical advice, but rather to offer readers information to better understand their lives and health. It is not intended to provide an alternative to professional treatment or to replace the services of a physician.