Where Your Lab's Ferritin Floor Actually Came From
The lower limit printed beside your ferritin result is a statistical interval, not a threshold for having enough iron. In a survey of 23 North American laboratories, 18 reported female
The Receipts
Where the numbers that dismiss you actually came from: who set each threshold, in what year, from which population — and what the research says now. One column, with its documents on the table.