Multivitamin supplements during pregnancy called needless expense

Most moms-to-be likely don't need prenatal multivitamin supplements, which can be a drain on the wallet, according to a U.K. review.

Multivitamin and mineral supplements are often promoted to pregnant women as a way of giving their child the best possible start. Nourishment before and during pregnancy is important, since it's an intense period of growth for mom and baby.

Supplements containing more than 20 vitamin and minerals are marketed to women before conception and during pregnancy to ward off complications such as neural tube defects like spina bifada, low birthweight and pre-eclampsia, researchers say in the July issue of Drug and Therapeutics Bulletin, published by BMJ.

The reviewers combed through published research on folic acid, vitamin D, iron, vitamins C, E, and A, and multivitamin supplements to see which have the strongest evidence to support national guidelines in the U.K.

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Their verdict? Stick with folic acid and vitamin D during pregnancy.

Folic acid had the strongest evidence base, with a daily dose of 400 micrograms or 0.4 milligrams recommended for women trying to conceive until 12 weeks of pregnancy.

Last year's Canadian guidelines for folic acid in pregnancy are similar, with higher amounts recommended for those at moderate or high risk for a neural tube defect.

Cleft palate, certain cardiac defects, urinary tract anomalies and limb reduction defects may also be sensitive to folate, also called vitamin B9, according to the Society of Obstetricians and Gynaecologists of Canada (SOGC).

The evidence for vitamin D supplementation in all pregnant women was less clear, based on the gold standard of randomized control trial evidence. The U.K. team recommended 10 micrograms of vitamin D daily throughout pregnancy and breastfeeding, with a higher dose suggested for some women.

Promote healthy diet

"We found no evidence to recommend that all pregnant women should take prenatal multi-nutrient supplements beyond the nationally advised folic acid and vitamin D supplements, generic versions of which can be purchased relatively inexpensively," the reviewers concluded.

"The primary focus should be on promoting a healthy diet and improving the use of folic acid supplements, which have a poor uptake, particularly among those from lower income families."

Dr. Danielle Martin,a family physician in Toronto and a contributor to CBC Health, says basic supplements are sufficient.

"I see women in my office with bags of expensive pregnancy supplements," Martin said in an email. "I tell them all they need is a little folic acid in the first trimester and then some iron in the third, but these pill-makers have some good advertising!"

"Maintenance of maternal iron stores is usually assured if low level iron supplements are provided during the last half of the pregnancy," the Canadian society said.

The reviewers suggest greater promotion of simple vitamin preparations. They added pregnant women should also be advised to avoid vitamin A supplements, which can be risky to the baby.