What it is
Membrane transport is the crossing itself: getting a molecule from the gut lumen, across the intestinal epithelium, and into circulation or a cell. It is the step where fulvic acid's small size stops being a chemical curiosity and starts to matter functionally.
How it works
The sequence is: chelation binds a mineral into a small, absorbable complex; the low molecular weight of the fulvic carrier lets that complex cross the wall; the cargo is delivered inside. Humic and fulvic acids have been described as carriers that enhance the intestinal absorption of what they hold.
At a glance
What the literature shows
Mostly mechanistic and preclinical; the carrier framing is consistent across the reviews.