**The consumption of food that contains 150% Daily Value or 27 mg of iron *only once* by a healthy person should not result in any side effects.**

This is because Tolerable Upper Intake Levels (maximum daily intake unlikely to cause adverse health effects) for iron for individuals age 0-13 is 40 mg and for those age 14 or older is 45 mg ([Office of Dietary Supplements, NIH.gov][1]).

**Is acute iron overdose from food (not supplements) in healthy adults possible?** 

Not likely. According to [Office of Dietary Supplements, NIH.gov][1]:

> Adults with normal intestinal function have very little risk of iron
> overload from dietary sources of iron.

and

> acute intakes of more than *20 mg/kg iron from supplements or medicines*
> can lead to gastric upset, constipation, nausea, abdominal pain,
> vomiting, and faintness.

For a 70 kg man, this is 1,400 mg of iron, which is virtually impossible to get from foods even [highest in iron][2].

**What happens with iron consumed in excess of the body needs?**

Most of the excessive iron probably won't be absorbed ([AJCN][3]):

> If an individual requires more iron, more iron will be mobilized from
> body iron stores and there will be an increase in intestinal iron
> absorption. However, if the body is iron replete, these processes will
> be downregulated.

According to [vivo.colostate.edu][4]:

> Iron abundance states: iron within the enterocyte [intestinal lining
> cell] is trapped by incorporation into ferritin and hence, not
> transported into blood. When the enterocyte dies and is shed, this
> iron is lost.

**Would a single ingestion of 150% Daily Value of iron be harmful for a person with hemochromatosis?**

Not likely. According to the article [The myths and realities of hemochromatosis
(Canadian Journal of Gastroenterology)][5]:

> Although dietary iron is the source of excess iron in hemochromatosis,
> a decrease in dietary iron has not been shown to decrease iron stores
> in hemochromatosis.


  [1]: https://ods.od.nih.gov/factsheets/Iron-HealthProfessional/
  [2]: https://nutritiondata.self.com/foods-000119000000000000000-w.html
  [3]: https://academic.oup.com/ajcn/article/106/suppl_6/1559S/4823167
  [4]: http://www.vivo.colostate.edu/hbooks/pathphys/digestion/smallgut/absorb_minerals.html
  [5]: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2657669/