Question: Why does estrogen regulate tryptophan metabolism? Chris: I think that it's basically the body trying to make sure that the baby has enough niacin because chronic estrogen exposure would occur during pregnancy. When I was doing my niacin research, one thing that I found is that women seem to need more total niacin than men, but they seem to be better at making niacin from protein. What's really interesting is that the studies that were done that were used to make the RDA, there weren't comparisons in men and women, but two of the studies were men and two studies were in women. The standard deviations, meaning how much variation there was person to person, in how much niacin that they needed to normalize what they were looking at was way bigger in men than it was in women. This Q&A can also be found as part of a much longer episode, here: https://chrismasterjohnphd.com/podcast/2019/10/19/ask-us-anything-hormones-dr-carrie-jones-may-10-2019 If you would like to be part of the next live Ask Me Anything About Nutrition, sign up for the CMJ Masterpass, which includes access to these live Zoom sessions, premium features on all my content, and hundreds of dollars of exclusive discounts. You can sign up with a 10% lifetime discount here: https://chrismasterjohnphd.com/q&a ====== DISCLAIMER: I have a PhD in Nutritional Sciences and my expertise is in performing and evaluating nutritional research. I am not a medical doctor and nothing herein is medical advice. PLEASE NOTE: As a result of the COVID-19 crisis and the time I am committing to staying on top of relevant research, as well as the high volume of questions I receive, it may take me extra time to respond to questions here. For an up-to-date list of where I respond to questions most quickly, please see the contact page on chrismasterjohnphd.com. =======