L-Leucine Supplementation May Be Safe During Pregnancy

TOKYO--L-leucine, an essential amino acid and a common ingredient in dietary supplements, does not affect the outcome of pregnancy or development of the fetus, according to a rat study published in the September issue of Food and Chemical Toxicology (42, 9:1505-11, 2004) (www.sciencedirect.com/science/journal/02786915).

To investigate the possibility of fetal toxicity in rats exposed to L-leucine, researchers administered 11- to 12-week old dams an aqueous solution of L-leucine at doses of 300 or 1,000 mg/kg body weight on gestational days 7 to 17 (the full gestational period was 20 days). Caesarean section on day 20 revealed no effects on litter size or weight of live-born fetuses, the number of corpora lutea, the implantation index or placental quality. No abnormalities in gender ratio, external irregularities, or significant treatment-related variations in visceral and skeletal pathologies were observed in a series of external, visceral and skeletal examinations conducted on the fetuses. The researchers concluded L-leucine, administered orally during organogenesis at doses up to 1,000 mg/kg body weight, did not affect the outcome of pregnancy or cause fetotoxicity in rats.