Vitamins, Arginine May Reduce Risk of Pre-eclampsia
The risk of pre-eclampsia, a dangerous condition that affects about 5 percent of first-time pregnancies, may be reduced if women take vitamins and arginine. An international research team reports that a supplement containing these ingredients could help women at high risk for the condition.
Pre-eclampsia is hazardous for mother and child
Thousands of women and infants die or become very ill each year from pre-eclampsia, a condition that can develop gradually but often starts suddenly after 20 weeks of pregnancy. Signs and symptoms typically include high blood pressure and excess protein in the urine, and may also involve severe headaches, vision changes, upper abdominal pain, dizziness, nausea or vomiting, and sudden weight gain (usually more than 2 pounds per week).
Known risk factors for preeclampsia include a personal or family history of preeclampsia, age (younger than 20 and older than 40), obesity, and history of high blood pressure, migraine, diabetes, kidney disease, or rheumatoid arthritis. However, other factors also have been proposed, including a deficiency of L-arginine (arginine), an amino acid that helps maintain blood flow during pregnancy, and a deficiency of vitamins.
To test the impact of arginine and vitamins/antioxidants on the development of pre-eclampsia, 672 women at high risk for the condition were studied in Mexico City. The pregnant women were randomly assigned to one of three groups and started on a daily food supplement or placebo around 20 weeks of pregnancy.
A total of 228 women received food bars that contained both arginine and vitamins, 222 received bars that contained only vitamins, and 222 received bars containing neither supplements (placebo bars). The women were asked to eat two bars daily until delivery.
Each bar contained 3.3 g arginine, 250 mg vitamin C, 200 IU vitamin E, 200 mcg folic acid, 25 mg niacin, 2 mg vitamin B6, and 4.8 mcg vitamin B12.
The researchers measured blood pressure and arginine levels every three to four weeks at the hospital. Overall, the proportion of women who developed pre-eclampsia was 30.2 percent in the placebo group, 22.5 percent in the antioxidant only group, and 12.7 percent in the arginine plus antioxidant group.
Thus, women in the arginine plus vitamin group were significantly less likely to develop pre-eclampsia compared with women in the placebo group. Women who ate the combination bars also had a significantly reduce risk of premature birth when compared with the placebo group. Use of vitamins alone did not result in a significant reduction in risk of pre-eclampsia.
Before arginine and vitamins can be recommended for women at high risk for pre-eclampsia, more research is needed to answer several questions, including how do arginine and vitamins work together, and are there any potentially harmful effects. The study’s authors also suggested a comprehensive systematic review be conducted “of the numerous inconsistent strands of evidence relating to L-arginine and its possible effects on pre-eclampsia.”
Vadillo-Ortega F et al. British Medical Journal 2011; doi: 10.1136/bmj.d2901