ZincNutrition library

Zinc

mg · Minerals

A cofactor for hundreds of enzymes involved in DNA synthesis, cell division and immune function — critical during the fastest-growth periods.

How this interacts

Meal-resolved zinc

Per meal: zinc and phytate are converted to a molar ratio (mg ÷ molecular weight). Absorption fraction follows the IZiNCG/WHO bioavailability bands — ~50% when phytate:zinc is low, tapering to ~15% when it's high — smoothly interpolated between those bands rather than stepping abruptly. Summed to a day total and compared against an absorbed-zinc target (the gross RDA × the ~27% absorption fraction the RDA itself already assumes for a moderate-phytate diet).

Phytate vs. minerals

Phytic acid (IP6), concentrated in the bran/germ of grains, legumes and nuts, chelates zinc, iron and (more mildly) magnesium in the gut, blocking some of their absorption. The effect is dose-dependent: more phytate relative to the mineral means a larger blocked fraction. Vitamin C specifically counteracts phytate's effect on iron (not zinc) by forming an absorbable iron-ascorbate complex.

Tracked by these blood markers

Serum zincµmol/L

Trimester focus

Stage	For the mother	For the baby
First trimester	Supports the immune adaptations of early pregnancy.	Essential for DNA synthesis during the most rapid cell-division period.
Second trimester	Continues supporting maternal immune and tissue-repair function.	Supports organ growth and ongoing cell division.
Third trimester	Stays important for tissue growth and immune function.	Supports continued growth and the developing immune system.

Connections

What links here

Evidence & sources

Evidence-backed^[1] Zinc absorption falls as phytate:zinc molar ratio rises
IZiNCG/WHO bioavailability classes by phytate:zinc molar ratio: <5 ~50% absorption ("high"), 5-15 ~30% ("moderate"), >15 ~15% ("low") — formalised in a mathematical model of zinc absorption vs dietary zinc and phytate.
Evidence-backed^[2] Absorbed-zinc target derives from the dietary RDA's own assumption
The IOM zinc RDA is itself a factorial estimate (physiological requirement ÷ an assumed absorption fraction for a moderate-bioavailability mixed diet, ~27%) — this engine's absorbed-zinc target is that same fraction of whichever gross target applies for the phase, so it automatically tracks any future correction to the gross target.

References

Target note

Oyster-driven; watch the 40 mg UL. The Assessment tab scores modelled ABSORBED zinc (phytate-limited per meal, like iron) against an absorbed target, alongside the separate gross 40 mg UL check.