Folic acid. The name sounds like it might be dangerous, a caustic acid substance and not good for health. But it is actually a very important vitamin and therefore essential to your life and your health. It is also the most commonly deficient vitamin in Americans and the average American diet provides only about half the RDA, the amount recommended by the Food and Nutrition Board. Folic acid is found in green leaves, such as spinach, asparagus, beans (legumes) and especially in brewers yeast and liver. If you don't like any of those foods, try eating butterfly wings for an exotic source health food.
Deficiency of folic acid is an important cause of birth defects, particularly spina bifida, a defect in the formation of the lower back which leaves the spinal cord exposed. Several studies have confirmed the value of folic acid in preventing these "neural tube defects" and the FDA now recommends that prospective mothers take folic acid supplements because women are unlikely to obtain a sufficient amount of folate to support a healthy pregnancy unless a supplement is taken. If it were only to prevent birth defects, I strongly recommend that all women of child-bearing age take a folic acid supplement of at least 0.4 mg and preferably twice that much on a regular basis.
Folic acid has many other actions that you need to know about. This vitamin is especially important in patients whose illness requires hospital care. Research reports indicate that a third of the psychiatric patients and two thirds of the medical patients in hospital are low in folic acid. Deficiency is not necessarily due to poor diet. Intestinal malabsorption and treatment with female hormones and birth control pills also cause low folic acid levels. Anticonvulsant therapy with Dilantin is most likely to block absorption and interfere with conversion to the active form in the brain and this can cause depression and loss of mental acuity, which are responsive to folic acid treatment.
At menopause many women produce extra amounts of homocysteine, an amino acid by-product of protein. Homocysteine is a powerful solvent, capable of attacking collagen and hence weakening all tissues, but especially blood vessels and bone. When bones weaken they lose calcium, become porous, hence the name, osteoporosis. Deficiency of folic acid (as well as B12 and B6) causes increased homocysteine accumulation and hence aggravates osteoporosis. Damage can be prevented by folic acid supplements and this therapy may be indicated even if folate blood levels are within the normal range. As you can see, there is more to osteoporosis than just calcium and there is more to folic acid than is revealed by simple measurement of blood levels. Functional tests, such as the presence of homocysteine, are actually more revealing.
The main chemical function of folic acid is in transporting a carbon atom in the form of a methyl group. This action has been put to good use in treating victims of methyl alcohol poisoning. A more common and therefore more important function of folic acid is in the manufacture of nucleic acids, essential for growth and repair in every cell in the body. Growing cells need folic acid; hence deficiency causes anemia and delays healing. Mature cells also need folic acid to assure repair of nucleic acids that get damaged by carcinogens, radiation and even by dietary oxidative by-products nucleic acids.
Cancer cells also need folic acid in order to grow and folic acid blockers, such as methotrexate, are sometimes used to curtail cancer growth; a technique that works best if folic acid, in turn, is used to promote healing in the "rescue" strategy in cancer chemotherapy. Folic acid has also been found effective against pre-cancerous cervical dysplasia. It is so effective here that abnormal cells can become normal again! Hence folic acid, along with vitamin A and vitamin C, which share this action, should be tried before resorting to surgical intervention.
Folic acid deficiency, even if temporary, has been found to weaken the immune system for about three months after since folate deficient lymphocytes do not recover function but must be replaced by new cells. Nerve cells are affected by folic acid in several ways. Methyl group transfer is critical to the production of choline, which is essential to repair cell membranes and in the production of acetylcholine, a key neurotransmitter. Folic acid is also essential in manufacture of catecholamine transmitters and in the removal of their end products, thus balancing the action of neurotransmitters, such as norepinephrine and epinephrine.
The RDA of folic acid is only 0.4 mg per day and doses larger than 3 mg can be over-stimulating. Emotional tension, irritability and headache can occur and there is a small increase in the risk of seizures at intake above 5 mg per day. On the other hand, large doses of folic acid are also reported to increase the pain threshold, ie. to reduce pain.
Large doses of folic acid, up to 80 mg daily, were given to 150 patients by Dr. Kurt Oster, who found that folic acid inactivates an enzyme, xanthine oxidase, and thus reverses damage to the blood vessel wall in atherosclerosis patients. There were no bad reactions to these large doses in his cases; however several studies point to danger in taking folic acid supplements greater than 5 mg daily. One of my patients had a seizure, a single episode of abrupt emotional overactivity followed by loss of consciousness and stiffening of the entire body, including tongue biting, which all came on 3 hours after a single 10 mg dose of folic acid and after a year of regular intake of about 1 mg daily. Two days later his folic acid blood level was over twice the normal. After stopping folic acid supplements, he is free of spells of emotional distress. The change is so obvious that his friends and acquaintances remark on it without being told what has happened.
On the other hand, megadose folic acid has been quite helpful in several of my depressed and a few of my schizophrenic patients. I will never forget the young man who recovered from a schizophrenic episode only after increasing folic acid intake to 40 mg. He remained well for a year but relapsed when he stopped the treatment. After that it required a 70 mg dose to defeat the illness.
Folic acid acts in concert with vitamin B12 in the production of adenosyl-methionine, an amino acid with a powerful ability to elevate mood and enhance mental acuity. One of the early signs of folate deficiency is mood depression and, as I said earlier, studies of hospitalized patients with depression show a tendency to low folic acid levels. When depression is accompanied by fatigue, treatment with folic acid is particularly likely to work.
Wheat allergy or intolerance is a common cause of folate deficiency. Gluten, the wheat protein, causes inflammation of the intestine and mal-absorption of folic acid in sensitive individuals. Infection with the parasite, Giardia lamblia, can also inflame the bowel and interfere with folate absorption. It is a good idea to check folic acid levels in anyone who suffers from persistent intestinal symptoms, particularly diarrhea or excessive gas and bloating. Since folate must be digested by pancreatic juice in the duodenum, any malfunction in that area is likely to interfere with this vitamin.
There are many other indications to consider folic acid therapy. Neuropathy, nerve damage, is one of these, restless legs another. Post-partum depression and confusional states of the elderly are two additional psychiatric needs for folic acid. Aplastic anemia, even if due to a poisoning or drug reaction, may be responsive to folic acid. Recovery from any acute illness or trauma is likely to benefit from extra folic acid.
Folate deficiency is rare in breast fed infants but common in infants fed cows milk and commercial formula. Due to heat treatment, pasteurization, a milk protein that transports folate into the blood stream is destroyed. Without this protein, half the folic acid in food and supplements never makes it into the tissues where it is required for optimal cell function. Does this contribute to impaired growth and impaired brain development? I really worry about that when I know that the majority of American mothers do not nurse their babies and that the level of intellectual ability, as measured by scholastic test scores (SAT) has declined over 10 percent in the past 20 years. I think it is more likely that impaired brain development is behind this disaster than any lack of ability or effort on the part of our teachers and schools. When it comes to feeding children, Mother Nature still seems to know best! Natural foods in their raw state contain plenty of folic acid.
Richard A. Kunin, M.D. ©2000