Prenatal multivitamin supplementation decreases low birth weight risk

New research shows that women who supplement with multivitamins have a lower risk of delivering a low birth weight infant compared to those who receive only standard iron and folic acid supplements.

An inadequate intake of micronutrients during pregnancy increases the possibility of nutritional deficiencies that can affect the normal growth of the baby. Low birth weight is often associated with increased infant mortality.

A new meta-analysis published online on June 9, 2009 in the Canadian Medical Association Journal showed that pregnant women that supplemented with multinutrient formulas experienced a reduced risk of giving birth to low birth weight babies compared with the risk experienced by women who did not receive the extra nutrients.

Researchers identified 13 trials that compared the effects of a multivitamin supplement with a placebo, or with iron and folic acid, which are currently recommended for pregnant women by the World Health Organization. Multivitamin supplements evaluated in the trials included a combination of vitamins A, B1, B6, and folic acid, and the minerals zinc, iron, and copper.

Compared to those receiving a placebo, women who supplemented with multivitamins had a 19 percent lower risk of delivering a low birth weight infant. The multivitamin group also had a 17 percent lower risk than those who received only the standard iron and folic acid supplements. The risk of preterm birth and the risk of delivering infants who were small for their gestational age were approximately the same among treatment and control groups.

Prenatal multivitamin supplementation was associated with a significantly reduced risk of low birth weight when compared with iron-folic acid supplementation alone.

Source: Effects of prenatal multimicronutrient supplementation on pregnancy outcomes: a meta-analysis, Shah et al, CMAJ. 6/2009; 180(12)

Fish oil intake during pregnancy may be associated with lower asthma incidence during childhood

New research has shown a significant correlation between fish oil intake during pregnancy and asthma incidence during childhood. Children whose mothers supplemented with fish oil during pregnancy were significantly less likely to be diagnosed with childhood asthma than children from non-supplementing mothers.

Current evidence suggests that asthma development may be associated with maternal intake of marine omega-3 fatty acids during pregnancy. A recent study was conducted to examine whether an increase in omega-3 fatty acid intake during pregnancy could affect risk of asthma in their offspring.

A population-based sample of 533 women with normal pregnancies were randomly assigned 2:1:1 to receive either four one-gram fish oil capsules/day providing 2.7 grams of omega-3 fatty acids, four similar looking one-gram capsules/day with just olive oil, or no capsules at all.

During the 16 years that passed since childbirth, the rate of asthma incidence was reduced by 63% and the rate of allergic asthma was reduced by 87% in the fish oil group as compared to the olive oil group.

Assuming that the intake of olive oil had no significant influence one way or another, these results support the theory that increased fish oil omega-3 fatty acid supplementation in late pregnancy may provide important preventive potential in relation to childhood asthma development. Additional studies on this subject are currently in progress, which should shed more light on the mechanism behind this promising discovery.

Source: Fish oil intake compared with olive oil intake in late pregnancy and asthma in the offspring: 16 y of registry-based follow-up from a randomized controlled trial, Olsen et al, American Journal of Clinical Nutrition, Vol. 88, No. 1, 167-175, July 2008

Prenatal zinc supplementation influences lean tissue growth in infants

A double-blind study recently published in the American Journal of Clinical Nutrition showed a significant positive correlation between supplemental zinc during pregnancy and infant growth throughout the first year of life.

It has been suggested that maternal zinc intake influences growth in utero and in the first stages of growth after birth. In a recent study, researchers assessed the effect of maternal zinc supplementation during pregnancy as well as its effects on infant growth during the first twelve months.

A randomized, double-blind, controlled trial of prenatal zinc supplementation was conducted among women in Lima, Peru between 1995 and 1997. Women enrolled during the second trimester and were assigned to receive daily supplements with zinc (15 mg zinc + 60 mg iron + 250 mcg folic acid) or without zinc (just 60 mg iron + 250 mcg folic acid) through pregnancy to one month after delivery. At birth, 546 infants were followed for 12 months to assess growth. Measurements were collected monthly while health status and dietary intake were monitored weekly.

Infants born to mothers supplemented with zinc had significantly larger average growth measures beginning at 4 months and continuing through month 12. Prenatal zinc was associated with greater weight, calf circumference, chest circumference, and calf muscle area.

In this population of women, zinc supplementation during pregnancy resulted in children with better growth measures (which were in turn associated with healthy increases in lean tissue mass).

Source: Maternal zinc supplementation and growth in Peruvian infants, Iannotti et al, American Journal of Clinical Nutrition, Vol. 88, No. 1, 154-160, July 2008

Vitamin D supplementation in early pregnancy may help prevent preeclampsia

Vitamin D deficiency early in pregnancy is associated with a five-fold increased risk of preeclampsia, according to a new study published in the Journal of Clinical Endocrinology and Metabolism.

In newly published research, scientists evaluated data and blood samples taken from women and newborns between 1997 and 2001 enrolled in a study designed to examine risk factors for preeclampsia. This serious complication of pregnancy is marked by elevated blood pressure and edema (swelling) of the hands and feet, and is a leading cause of premature delivery and maternal and neonatal complications including death. The results of the study show that a maternal vitamin D deficiency early in pregnancy is a strong, independent risk factor for preeclampsia. This increase risk continued even after adjusting for other known risk factors such as race, ethnicity and pre-pregnancy body weight.

Another concern was the fact that many of the women were taking prenatal vitamins, which typically contain 200 to 400 IU of vitamin D. "Even a small decline in vitamin D concentration more than doubled the risk of preeclampsia," noted James M. Roberts, M.D., senior author of the study. "And since newborn's vitamin D stores are completely reliant on vitamin D from the mother, low vitamin levels also were observed in the umbilical cord blood of newborns from mothers with preeclampsia." The researchers concluded that maternal vitamin D deficiency may be an independent risk factor for preeclampsia and vitamin D supplementation in early pregnancy should be explored for preventing preeclampsia and promoting neonatal well-being.

About preeclampsia

Source: Maternal Vitamin D Deficiency Increases the Risk of Preeclampsia, Lisa M. Bodnar, Janet M. Catov, Hyagriv N. Simhan, Michael F. Holick, Robert W. Powers, and James M. Roberts, Journal of Clinical Endocrinology & Metabolism September 2007, Vol 92, No.9:3517-22

Vitamin D deficiencies widespread among pregnant women and infants despite prenatal vitamin usage

Vitamin D deficiency early in life is associated with rickets, a disorder characterized by soft bones. New research has shown that despite taking a prenatal vitamin, vitamin D deficiency is very common in pregnant women and newborn infants. Higher-dose supplementation and increased sun exposure is needed to improve maternal and infant vitamin D status.

Even among those taking prenatal multivitamin supplements, vitamin D levels were found to be insufficient or deficient in pregnant women, particularly in African-American women and women living in northern regions, according to new research published in the Journal of Nutrition. Researchers took blood samples from 400 pregnant women - 200 black women and 200 white women - before 22 weeks gestation and again after delivery. More than 80% of African American women and nearly half of white women tested at delivery had levels of vitamin D that were insufficient, even though more than 90% of them used prenatal vitamins during pregnancy. In addition, umbilical cord blood from newborns showed 92.4% of African American babies and 66.1% of white infants had insufficient vitamin D levels at birth, leaving them at risk for rickets and other health problems. A newborn relies completely on its mother for its vitamin D stores. These results suggest that black and white pregnant women and newborns residing in the northern US are at high risk of vitamin D insufficiency, even when mothers regularly take prenatal vitamins. Higher-dose supplementation is needed to improve maternal and infant vitamin D status.

Source: High Prevalence of Vitamin D Insufficiency in Black and White Pregnant Women Residing in the Northern United States and Their Neonates, Lisa M. Bodnar, Hyagriv N. Simhan, Robert W. Powers, Michael P. Frank, Emily Cooperstein and James M. Roberts, Journal of Nutrition 137:447-452, February 2007

Source: USANA Health Sciences

Multivitamin use lowers preeclampsia risk

High blood pressure during pregnancy (preeclampsia) can result in serious complications for the mother and child. Results from a new study show that regular use of a multivitamin supplement in the months before and during pregnancy may reduce the risk of preeclampsia by as much as 71%.
Lean women who used multivitamins before and during their pregnancies reduced the risk of preeclampsia, a complication of pregnancy characterized by elevated blood pressure, swelling of the extremities and protein in the urine. If untreated, the condition can progress to eclampsia, which can lead to seizures, coma, and the death of the mother or child. The study involved 1,835 pregnant women enrolled in the Pregnancy Exposures and Preeclampsia Prevention Study. All women were at less than 16 weeks' gestation and were asked whether they regularly used multivitamins or prenatal vitamins in the past six months. Women that reported using a multivitamin or prenatal during the previous six months had a 45 percent lower risk of preeclampsia than non-users. The reduction in risk was more significant among lean women. When lean women were analyzed separately, those who used multivitamins had a 71 percent lower risk of preeclampsia than nonusers. These results suggest that regular use of a multivitamin supplement in the months before and during pregnancy may help to prevent preeclampsia, particularly among lean women.

Source: Periconceptional Multivitamin Use Reduces the Risk of Preeclampsia, Lisa M. Bodnar, Gong Tang, Roberta B. Ness, Gail Harger and James M. Roberts, Am J Epidemiol. 2006 Jun 13, 164(5):470-477

Multivitamin use before pregnancy reduces risk of preterm births

Pre-term birth is associated with many health risks as well as a lower rate of infant survival during the first year of life. Women who take a multivitamin before conception have only half the risk of preterm delivery than those who wait until after becoming pregnant to start taking nutritional supplements.

A study published in the November 2004 issue of the American Journal of Epidemiology showed that the use of multivitamin supplements by women prior to becoming pregnant was associated with fewer preterm deliveries. Preterm birth is defined as birth at less than 37 weeks of gestation and is associated with a lower rate of infant survival during the first year of life. Researchers utilized data from the Pregnancy, Infection and Nutrition Study which recruited 2,010 women during their 24th to 29th week of pregnancy. They compared the incidence of preterm delivery among women who took multivitamins prior to conception, before conception and during pregnancy, during pregnancy only, or not at all. Women who took a multivitamin supplement before conception had half the risk of early and late preterm delivery than those who took no vitamins. Women used multivitamins during pregnancy only had approximately the same amount of preterm births than women who took none at all. This study, as well as many previous studies, reinforces the concern that waiting until pregnancy is diagnosed may be too late for nutritional intervention to benefit many pregnancy outcomes.

Source: Multivitamin Use and the Risk of Preterm Birth, Anjel Vahratian, Anna Maria Siega-Riz, David A. Savitz, and John M. Thorp Jr, Am J Epidemiol. 2004 Nov 1;160(9):886-92.