Negative Studies
- 17 August 1989
- journal article
- Published by Massachusetts Medical Society in New England Journal of Medicine
- Vol. 321 (7), 464-466
- https://doi.org/10.1056/nejm198908173210708
Abstract
In this issue of the Journal is a report of a study showing that if women take vitamins around the time of conception, it has no effect on the incidence of neural-tube defects in the newborn.1 This is a large, carefully designed and analyzed case–control study with negative results — that is, the exposure, in this case vitamins, was not found to be effective. The results are in contrast to those of earlier studies that did find an association between vitamin use in pregnant women and a lower incidence of neural-tube defects in their offspring.2 3 4 5 It is widely believed that . . .Keywords
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