Researchers at Newcastle University in England, led by Dr. Georg Lietz, found 47 percent of volunteer group of 62 women carried a genetic variation that prevented their bodies from effectively converting beta-carotene into vitamin A.
The findings suggest beta carotene may not be an effective substitute for vitamin A for women whose bodies are not able to make the conversion, Lietz said. Beta carotene has been suggested for pregnant women since a 1987 study linked too much vitamin A with certain birth defects.
"Worryingly, younger women are at particular risk," Lietz said in a statement. "The older generations tend to eat more eggs, milk and liver which are naturally rich in vitamin A, whereas the health-conscious youngsters on low-fat diets are relying heavily on the beta-carotene form of the nutrient."
The study findings were published in the Federation of American Societies for Experimental Biology Journal and were presented at the Hohenheim Nutrition Conference in Stuttgart, Germany.