Question: How much iron can we absorb at once? Short Answer: High-dose iron will produce more total absorbed iron, but will also leave more in the gut, which could cause constipation or disturb the gut microbiome. If desperate for quick relief, 200 milligrams per day of iron taken in the morning will work faster than lower doses or the same dose taken in the afternoon. For most people, however, I believe it is best to start with 18 milligrams of iron, and only increase it to 27 or 36 milligrams, or higher, if needed. If it is difficult to raise iron with a supplement, try eating a temporary carnivore diet that includes egg yolks but not whites, or at least try taking your iron with a breakfast that matches this description. This is a clip from a live Q&A session open to CMJ Masterpass members. In addition to this episode, you can access two other free samples using this link: https://chrismasterjohnphd.substack.com/p/questions-on-vitamin-d-sulfate-synthesis  In that batch of free episodes you will also find the answers to these questions: Is It Important to Get Vitamin D Sulfate Specifically From the Sun? What cofactors are needed to synthesize and recycle BH4? If you want to become a Masterpass member so you can participate in the next live Q&A, or so you can have access to the complete recording and transcript of each Q&A session, you can save 10% off the subscription price for as long as you remain a member by using this link to sign up: https://chrismasterjohnphd.substack.com/qanda Learn more about the Masterpass here: https://chrismasterjohnphd.substack.com/about This snippet is from the February 15, 2023 AMA. The full recording and transcript is reserved for Masterpass members. Here is a preview of what’s included: Is It Important to Get Vitamin D Sulfate Specifically From the Sun? What cofactors are needed to synthesize and recycle BH4? What nutrients are important for long-term PPI use? For how long does transferrin saturation respond to recent iron-rich food? Muscle spasms: creatine, creatinine, sodium, and potassium. Hematologists ignore iron saturation. How to detox arsenic? Could folic acid supplements impair BH4 recycling? How to increase butyrate? More on hematologists and transferrin saturation. Here’s a link to the full AMA: https://chrismasterjohnphd.substack.com/p/recording-and-transcript-of-the-february