Absorption
Tea can cut iron absorption by about half
Black tea or coffee within ~60 minutes of iron-rich food or an iron pill can reduce non-heme iron absorption on the order of 50–80%. Move the tea two hours away, or pair the iron with vitamin C. Adaptin is the calorie tracker that measures the clash and shows the fix.
Non-heme iron (plants, most fortified foods, most pills) is sensitive to polyphenols in tea and coffee. Drink them in the same hour as the iron and a large fraction never makes it across the gut. Heme iron (meat) is more robust, which is why a steak with tea is a milder problem than an iron tablet with tea.
The practical fix
- Separate tea/coffee and iron by at least 2 hours.
- Pair iron with vitamin C (citrus, pepper) — Adaptin treats this as synergy, not just a warning.
- Do not swallow iron with a calcium-rich drink at the same time; calcium competes.
What Adaptin actually does
Forty-seven data-driven rules fire on a food or supplement log inside the rule window. Tea×iron is the loudest. The UI shows a magnitude (“reduces absorption ~50–80%”), the two items and the minutes between them, and a one-line fix. It is bundled into Notification Center, not a popup after every bite. Hypothetical pre-log check: see the clash before you commit.
This is nutrition education, not a lab assay. Magnitudes are typical literature ranges, not your personal absorption fraction.
Not medical advice. Iron deficiency and levothyroxine timing belong with a clinician.