Science Beat 6036

Another Reason for Women To Take Folic Acid
Since 1993, the U.S. Public Health Service has advised women who are capable of becoming pregnant to take 0.4 mg of folic acid per day to reduce the risk of having a child with spina bifida or other neural-tube defects. Recent research in Family Practice News (2003;33 [24]:10) suggests that supplementing with folic acid during the early weeks of pregnancy may also reduce the risk of congenital heart defects.

In the study, pregnancy outcomes were assessed in 1,884 women. After adjustment for potentially confounding factors such as maternal age, race, and smoking and alcohol use, women who took a daily folic acid supplement during the first six weeks of pregnancy (when the heart develops) were 54 percent less likely to have a baby with a specific congenital heart defect, compared with women who did not take folate daily. Folic acid?s protective effect increased with larger daily doses; it appeared that at least 400 mcg per day was necessary to reduce risk. No benefit was associated with starting the supplement after the first six weeks of pregnancy, or with taking folic acid before, but not during, pregnancy.

Good food sources of folic acid include leafy green vegetables, whole grains, folic acid-fortified grains, citrus fruits and meats. The consumption of folic acid-rich foods, however, does not guarantee that a woman will obtain enough of this nutrient to prevent birth defects. Studies have shown that genetic factors determine in part how the body handles folic acid, and that some women have a higher requirement for this vitamin than others. Other research has demonstrated that some women manufacture antibodies that bind to the folic acid receptors on the placenta, which could prevent the fetus from receiving an adequate supply of folic acid. In one study, these antibodies were present in the blood of 75 percent of women who had given birth to a child with a neural-tube defect, compared with only 10 percent of women who had given birth to a normal infant. Presumably, the inhibitory effect of these antibodies on folic acid utilization can be overcome by increasing the amount of the vitamin consumed. Thus, some women appear to have a higher than normal requirement for folic acid, and a failure to meet this requirement may contribute to the risk of certain birth defects.

Vitamin B12 Effective for Some Heartburn Sufferers
Supplementing with vitamin B12 can relieve the symptoms of dyspepsia in a subset of people who suffer from the problem, according to a report in the Journal of Clinical Gastroenterology (2003;37:230?3). People who responded to vitamin B12 in this study had the combination of symptoms suggesting slow passage of food from the stomach, intestinal infection with Helicobacter pylori and low blood levels of vitamin B12.

The stomach?s impaired ability to move its contents into the small intestine results in fullness, bloating and nausea after meals, and difficulty consuming large meals. Many people with dysmotility-like dyspepsia are infected with H. pylori, the organism associated with peptic ulcers, although these people do not themselves have ulcers. While the relationship between H. pylori infection and dysmotility-like dyspepsia is still unclear, infection with this organism can promote the development of vitamin B12 deficiency by reducing the secretion of stomach acid, which is necessary for absorption of B12 from food. Vitamin B12 plays a role in normal gastrointestinal function, but whether B12 deficiency causes dyspepsia has not been studied.

In the new study, 34 individuals with dysmotility-like dyspepsia, H. pylori infection and low serum vitamin B12 levels were assessed before and after a three-month course of vitamin B12. Each person received daily intramuscular injections of vitamin B12 (1,000 mcg) for 10 days, followed by 1,000 mcg per day orally for 80 days. The rate of gastric emptying and the severity of symptoms were determined before and at the end of the treatment. The average time required to empty the stomach contents decreased from 230 minutes at the start of the study to 98 minutes after vitamin B12 therapy. In addition, the severity of the intestinal symptoms improved by an average of 78 percent. These results suggest that correction of vitamin B12 deficiency can improve delayed gastric emptying and relieve symptoms in this particular subset of individuals with dyspepsia.

Alan R. Gaby, M.D., is the chief medical editor for Healthnotes Inc.
Copyright ? 2004 Healthnotes Inc.

Natural Foods Merchandiser volume XXV/number 4/p. 47