Buckle up Betty, this gets technical 🤓
The worries about Vitamin A causing an increased risk of birth defects comes from a 1995\xa0studywhere nearly 23,000 women got 10,000 IU+ of Vitamin A from supplements or processed foods during their first trimester and an increase in birth defects was observed…\xa0
But there were multiple flaws with the study (which you can read about\xa0here)...
And the biggest problem was that it ignored the multiple studies that contradicted it:
Contradictory Study #1
This 1990studyfound that among 25,000 births, doses of vitamin A over 40,000 IU per day carried a 2.7-fold higher risk of birth defects, but doses of vitamin A up to 20,000 IU or between 20,000 and 40,000 IU both carried a 50 percent lower risk of birth defects compared to no supplementation at all…
Contradictory Study #2
This 1996studyof 522,601 births found that the children of women supplementing with at least 10,000 IU of vitamin A in addition to a multivitamin had a lower risk of birth defects than those of women who did not supplement, although the association could not be distinguished from the effect of chance…
Contradictory Study #3
This 1997studyof 1,508 births found no relationship between birth defects and use of vitamin A supplements, fortified breakfast cereals, organ meats or liver.
Contradictory Study #4
This 1999 prospectivestudyof 311 mothers who consumed between 10,000 and 300,000 IU of vitamin A in the first trimester and a similarly sized group that did not supplement with vitamin A found no evidence of an increased risk of major malformations with increasing dose. The median dose was 50,000 IU. The group as a whole had a 50 percent lower risk of major malformations than those who did not supplement, and there were no major malformations in offspring born to mothers consuming more than 50,000 IU.
So yes, too much Vitamin A might be a problem (or might not based on those studies)...
But not enough Vitamin A is definitely a problem.\xa0
And taking all the evidence into account, we believe 10,000 - 20,000 IU of vitamin A during pregnancy is not only probably safe, but is going to lead to positive outcomes for fertility, conception, and the healthy development of mother and child.
We’re going to wrap this one up now, but before we do, here are some further resources on this topic: