Most other vitamins and supplements are less sensitive to fiber’s binding effects and are absorbed efficiently even when taken with food. While spacing them out can be a cautious approach, iron is the primary supplement where consistent separation is strongly recommended.
Why is iron specifically a concern?
Iron is particularly sensitive because it already has a lower absorption rate compared to many other nutrients. When soluble fiber binds to iron in the gut, it can further reduce how much your body absorbs.
In short: iron absorption is more easily affected — so spacing matters more.