February 26, 1999
Dietary Vitamin A Supplements Improve Maternal Survival in South Asia
In a field trial in 270 villages in rural Nepal, researchers from the Johns Hopkins School of Public Health showed that women had their risk of death from pregnancy lowered by about 40 percent after taking dietary supplements of vitamin A or beta-carotene, compared to women who did not take the supplements. The vitamin A study appeared in the February 28, 1999 issue of British Medical Journal.
Women suffer a high risk of death during and following pregnancy in rural South Asia, with mortality rates often 50 to 100 times higher than in industrialized countries. Death usually results from severe bleeding, obstructed labor, infection, and other causes. Malnutrition, especially vitamin A deficiency, also plays a critical role.
"This study suggests that the risk of maternal mortality in vitamin A deficient populations could be markedly lowered with only modest increases in vitamin A intake," said lead author Keith West, DrPH, professor, International Health, Johns Hopkins School of Public Health. He added that concern about maternal vitamin A deficiency has focused almost entirely on its effects on fetal and infant health and survival. Little attention has been given to the potential health and survival consequences for the mother.
The scientists carried out the field trial among married women of child-bearing age in the southeast plains of Nepal, where medical, prenatal and obstetric care are practically non-existent and 97 percent of all births occur in the home. Night blindness, a condition that is attributed to vitamin A deficiency, often occurs in ten percent or more of women during pregnancy. The trial was reviewed and approved by the Nepal Health Research Council in Kathmandu, the Joint Committee on Clinical Investigation at the Johns Hopkins School of Medicine, and the (International) Teratology Society. Villages were randomly assigned for women to receive weekly supplements containing recommended dietary amounts of vitamin A or beta-carotene, or a placebo. The trial's purpose was explained at community meetings, and written consent to participate was obtained from subdistrict leaders during the year prior to starting. Verbal consent to participate was obtained from the women.
Over a three and one-half year period, local volunteers carried out weekly home visits to over 44,000 women to provide them with a supplement and track pregnancies and their outcomes. A total of 20,119 women became pregnant 22,189 times. There were 110 maternal deaths. Few of these occurred in the presence of medical practitioners. Therefore, the scientists attempted to identify the likely causes by interviewing family members. This information was reviewed by two physicians who then assigned causes of death.
Mortality rates related to pregnancy occurring in the placebo, vitamin A, and beta-carotene supplemented groups were 704, 426, and 361 deaths per 100,000 pregnancies, respectively (compared to a rate of about 8 per 100,000 in the United States). These differences reflect 40 percent and 49 percent reductions in mortality among women taking vitamin A or beta-carotene supplements, respectively. The overall average reduction was 44 percent. Since the three groups of women were comparable at the outset of the trial with respect to many demographic, socioeconomic, nutritional, and medical factors, the researchers believed it unlikely that factors other than the dietary supplements could have influenced maternal mortality to this degree. Although information on causes of death was inconclusive, the evidence suggested that fewer deaths from infection may have occurred in the vitamin A and beta-carotene groups.
Currently, weekly low-dose vitamin A or beta-carotene supplement programs do not exist for women in the developing nations, although weekly iron supplementation is being debated as a potential, cost-effective way to prevent maternal iron deficiency and anemia in the developing world.
"The study findings indicate that an adequate dietary intake of vitamin A (or beta-carotene) may complement efforts to provide prenatal and obstetric care to improve maternal survival in the developing world," said Dr. West.
Support for this study was provided by the Office of Health and Nutrition, U.S. Agency for International Development (USAID), Washington DC.Public Affairs Media Contacts for the Johns Hopkins Bloomberg School of Public Health: Tim Parsons or Kenna Brigham @ 410-955-6878 or firstname.lastname@example.org.