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TERATOGENICITY OF VITAMIN A.

The synthetic retinoid isotretinoin, used to treat severe acne, is known to be teratogenic. This study corroborates a growing suspicion that vitamin A itself causes birth defects. Researchers from Boston University interviewed nearly 23,000 women between week 15 and week 20 of pregnancy about their diet and use of vitamins before conception and during the first trimester. When they tracked the outcomes of the pregnancies, they found 339 birth defects, including 121 of cranial-neural-crest origin (i.e., craniofacial, central nervous system, thymus, and heart defects). Women who reported daily consumption of more than 15,000 IU of vitamin A from food and supplements had a significantly higher prevalence of babies with cranial- neural-crest defects than women who ingested less than 5000 IU (1.8 vs. 0.51 percent). Vitamin A supplements were largely responsible for this effect: women taking more than 10,000 IU daily from supplements were nearly five times as likely to have a baby with these defects as women taking less than 5000 IU. Comment: Based on this study and other evidence, an editorialist suggests that women who are pregnant or considering pregnancy should not take more than 8000 IU of vitamin A per day.

— AS Brett

Published in Journal Watch General Medicine December 5, 1995

Citation(s):

Oakley GP; Erickson JD. Vitamin A and birth defects: continuing caution is needed. N Engl J Med 1995 Nov 23 333 1414-1415.

• Medline abstract (Free)

Rothman KJ, et al. Teratogenicity of high vitamin A intake. N Engl J Med 1995 Nov 23 333 1369-1373.

• Medline abstract (Free)

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