Hey there! Wasn't that interesting? Thanks for bringing that up. An easy thing to try.
No, I don't know specifically what they were using in terms of vitamins and minerals. The article says John Berardi has tried multivitamin/multimineral supplementation with "several" fitness/figure competitors, so it's more of an anecdotal thing that he noticed, maybe with a small number of people. There is no mention of a formal study or paper in the references, but that would certainly be worth a try, right?
Sample size n = 1 here, but I haven't had a problem with loosing my period for at least 3 years now, and I did improve my supplementation in that time. I'm able to work hard in the gym, but I discovered that I don't do well with really low carbs, or with intermittent fasting that's anything beyond a natural 7 pm to maybe 9 am window. I keep my weight between 5-12 pounds above what would be a figure contest weight for me.
I'm not a big supplement person, but just for reference, I do take a multivitamin with minerals, B vit complex, D3, fish oil, chelated Mg, calcium, and glucosamine/ chondroitin for just general health. For performance just BCAAs and Creatine.
I'd be interested to hear about other women's vitamin/mineral supplementation. It's not something I know a lot about.