Pregnant women who lack sufficient amounts of the B-vitamin biotin may be increasing their chances of having a child with birth defects, new research published in the February issue of the American Journal of Clinical Nutrition suggests.
"Researchers have been concerned for many decades that the nutrient status of pregnant women could have both beneficial and deleterious effects on their foetuses," Dr Donald M. Mock, of the University of Arkansas for Medical Sciences, told Reuters Health.
"Our lab is pursuing the possibility that biotin deficiency could be a cause of birth defects in humans."
Previous research has shown that lab animals with a deficiency in biotin maintain normal health, but are more prone to having babies with birth defects such as cleft palate. The relationship between a maternal deficiency in biotin and the negative effects on the foetus, however, remain unexplained.
Dr Mock and his researchers noted however, that previous studies provide evidence that many pregnant women eating a normal diet show increased urinary excretion of the organic acid 3-hydroxyisovaleric acid (3-HIA), which may be a marker for biotin deficiency.
The study was carried out on a group of 26 pregnant women who had high levels of 3-HIA excretion. Half of the women were given supplements of 300 micrograms of biotin daily for 2 weeks, while the other half were given placebo, or dummy, medicines.
The team found that all the women provided with biotin supplements showed a drop in their 3-HIA excretion to normal levels, while the women given placebo medicines continued to excrete high levels of 3-HIA.
The women who received biotin also had a significant increase in biotin excretion, while women who received the placebo showed no change in biotin excretion.
The results provide evidence that increased 3-HIA excretion indicates mild or moderate biotin deficiency, Mock said, but added : "It is not proof that biotin deficiency causes birth defects. This is just one more step in that line of research."
The researchers insisted that the results should be regarded as preliminary and not a recommendation for women to increase biotin levels in their diets. "It's not routinely provided in maternal supplements, and there's not enough evidence to strongly recommend it be included in maternal vitamins," Dr Mock commented.
The researchers plan to carry out further studies to determine if babies born with cleft palate have signs of biotin deficiency in their cord blood, or even conduct a large, randomized controlled trial to see whether widespread biotin supplementation would reduce the numbers of babies born with cleft palate.
"After that, there may be a mandate to make sure it is in maternal vitamins," Dr Mock said. "This is potentially important in the long run."