Health Professional Information:
Why prescribe a prenatal high dose folic acid
multivitamin-mineral supplement?

Women suffering from epilepsy:

There is clear evidence that folic acid supplements reduce the risk of NTDs in women taking antiepileptic drugs. Women with epilepsy exposed to anticonvulsant drugs in pregnancy have approximately twice the risk of bearing children with congenital malformations than that of the general population. Most antiepileptic drug treatments have been associated with this risk. Valproic acid and carbamazepine are known to increase the chances of having a child born with a NTD by ~ 1.5% and 0.5% respectively. Recently published data suggest that the risk of major malformations is significantly greater with valproic acid than with any other commonly used antiepileptic drugs.

Supplementation with multivitamins containing folic acid is considered effective in preventing several types of malformations, particularly neural tube defects. Women taking drugs that influence folic acid metabolism are considered at high risk of having a child born with a NTD. These women should take a prenatal multivitamin containing 5.0 mg of folic acid 3 months before conception and continue throughout pregnancy if, in the judgement of the attending health professional, the benefits of continued high dose folic acid supplementation outweigh potential risks. High doses of folic acid supplementation are known to mask the manifestation of vitamin B₁₂ deficiency. Some evidence also suggests that folate may precipitate or exacerbate the progression of neurological complications associated with vitamin B₁₂ deficiency. Therefore, it is recommended that vitamin B₁₂ status be assessed before folic acid supplementation.

Women suffering from diabetes:

Pre-gestational diabetes results in a 3-4 fold increased risk of congenital malformations, apparently related to poor blood glucose control during embryogenesis. The rate of major fetal malformations may rise as high as 35% in patients with poor blood glucose control.

Malformations can include cardiac, skeletal and gastrointestinal anomalies and neural tube defects. The risk of fetal anomalies decreases (close to the general population's risk of two to three percent) when glucose levels are well controlled pre-conceptually. Patients should be advised to take 5.0 mg of folic acid per day.

The increased risk of developing malformations in the children of diabetic women is likely related to hyperglycemia, metabolic problems such as ketonemia, and possibly to genetic predisposition. Hypoglycemia is probably unrelated to the development of fetal anomalies.

Patients suffering from inflammatory bowel diseases:

There are many factors that may alter micronutrient status of patients with Inflammatory Bowel Diseases (IBD). Micronutrient deficiency may be caused by malabsorption, decreased food intake, medications (folic acid antagonists, e.g. 5-ASA drugs (containing aspirin), corticosteroids & cholestyramine) and/or intestinal losses (diarrhea).  Treatments are available to prevent potential vitamin deficiency. Recent publications and guidelines recommend the routine use of prenatal multivitamin supplements for all patients with underlying malabsorption disorders.  A prenatal multivitamin will meet the needs of most IBD patients.

Folic acid supplementation is of particular importance in patients with IBD because they may be folic acid deficient for two reasons: a) the disease itself and b) the use of folic acid antagonists to treat the disease. Continued supplementation with 5.0 mg of folic acid daily is therefore recommended 3 months before conception and continue throughout pregnancy if, in the judgement of the attending health professional, the benefits of continued high dose folic acid supplementation outweigh potential risks.

Epidemiological and clinical studies suggest that folic acid supplementation may result in the reduction of the risk of colorectal cancer. Patients with ulcerative colitis receiving folic acid supplementation may have a 62% lower incidence of intestinal problems including colorectal cancer.

Because of potentially masking vitamin B₁₂ deficiency in patients on long-term folic acid (5.0 mg daily) supplementation, monitoring of vitamin B₁₂ levels is recommended.

Hyperhomocysteinemia, which plays a role in high blood pressure, has been found to be more common in IBD patients compared to healthy populations. This disorder has been associated to lower levels (but not necessarily deficiency states) of folic acid and vitamin B₁₂, and could play a proinflammatory role in IBD. Folic acid and group B vitamins are known to reduce the level of homocysteine in the blood. Hyperhomocysteinemia has also been associated with pregnancy complications.

Multivitamin supplements are recommended on a daily basis for many reasons in IBD patients.

Taking folic acid reduces the risk of NTDs

There is strong evidence that prophylactic therapy with folic acid in a multivitamin, at least three months before and following conception, reduces the risk of fetal neural tube defects (NTDs). NTDs result from the improper development and closure of the neural tube during the third and fourth week of gestation. Pregnancies affected by a NTD may result in a miscarriage or stillbirth while children born with a NTD may have mild to severe disabilities or may even die in early childhood. NTDs include spina bifida, anencephaly and encephalocele.

Women at risk of having a child with a neural tube defect should take a prenatal multivitamin containing folic acid. This treatment should begin prior to pregnancy as neural tube and cardiac defects occur in the first 28 days after conception. Patients should start folic acid supplementation as soon as they stop taking contraceptive measures. It has been suggested that all women at risk should be given a folic acid supplement since 50% of pregnancies are unplanned. Otherwise, women should take prenatal vitamins at least three months prior to conception and during the first trimester of pregnancy.

Although the use of folic acid supplements during the periconceptional period reduces the number of NTDs, because of its multi-factorial origin, NTDs cannot be completely avoided by means of folic acid supplementation. The recurrence rate of 2-3% remains the same for women with a prior history of NTDs. Consuming 5.0 mg of folic acid daily has the potential of reducing the incidence of another NTD pregnancy by up to 72%. This is translated to a recurrence rate of only 1% for these women.

There is evidence that an increased intake of 0.4 mg/day of folic acid would result in reduced risk of neural tube defects for all women planning a pregnancy by ~ 36%. An increase of 1 mg/day of folic acid would decrease NTDs by 57% and the intake of a 5.0 mg/day would reduce the risk by about 85%. There is no medical evidence that taking more than 5.0 mg of folic acid daily will bring any further benefit in reducing the risk of NTDs.

IMPORTANT: Taking vitamin and mineral supplements during pregnancy does not eliminate the need for regular well-balanced nutrition.