A recent study has shown that women of child-bearing age should watch their intake of vitamin A, a conclusion not all of Iowa State faculty experts agree with.

The study found a correlation between the daily intake of vitamin A and birth defects. According to the study, if the intake of vitamin A exceeds 10,000 IU (international units), the chance of birth defects increases.

“The relationship has been known for quite some time, but the levels showing an effect are lower than ever reported,” said, Elisabeth Schafer, a professor of nutrition.

Vitamin A is an essential nutrient and is necessary during pregnancy.

The Recommended Daily Allowance (RDA) of vitamin A for pregnant women is 5,000 IU, which equals about 800 retinal equivalents (RE), said Pam Duitsman, a research scientist in the biochemistry department.

“I don’t agree with the analysis,” said James Allen Olson, an ISU distinguished biochemistry professor. Other data has proven that it takes more than 25,000 IU of vitamin A to increase the chances of birth defects, he said.

“People may run scared and try to eliminate vitamin A from their diets,” Olson said. “Not enough is just as harmful.”

Duitsman agreed. “I am afraid people will think they can’t take their vitamins when they are already deficient,” she said. A study Duitsman was involved with found that 30 percent of Americans have a vitamin A deficiency.

However, most people in this country have adequate reserves of vitamin A, Olson said. Unless you take supplements or eat fair amounts of liver, deficiencies are more of a concern than excesses of the vitamin, he said.

“About 40 percent of people in the United States take supplements of some kind,” Schafer said. There are no limits on the intake of supplements and it is easy to take excess, she added.

Schafer suggested that women eat lots of fruits and vegetables and not rely on supplements.