Excessive Iron - how to avoid?


Hello guys,

I am just planning my own DIY recipy, and a problem that I have occured is the iron intake.

Most mineral supplements already cover more than 100% of the daily ratio. If you then take oats as the main carb source you easily end up at 200 or even 300%.

How could this be avoid? And at which point an overdose of iron really becomes a problem?



Men need 8mg whilst women need 18mg - I believe this is why most supplements have more than 100% of the male requirement, as they want to provide enough for women too.

The tolerable upper limit is 45mg per day. However, it’s worth noting that non-haem iron (iron from a non-animal source) has a far lower bioavailability than iron from animals, so it is far less likely to cause any sort of toxicity, even above that 45mg limit.

However, to be absolutely safe, stay below the 45mg (you should be able to even with the iron from the oats with relative ease), and if you can’t, consider switching to an alternative micronutrient source that’s low in iron. When it’s available (looking like some time in November, though it could be delayed) I highly recommend getting axcho’s micronutrient mix. Details of its composition can be seen here: https://www.reddit.com/r/soylent/comments/4gx8bb/full_details_on_upcoming_micronutrient_mix_from/


Thanks for your answer.

Just quickly checked my recipy, and I end up at roughly 35g iron.

15mg from my favorite supplement pill
15mg from 250g oats
5mg from other ingredients

I will post the whole thing after I finished putting everything in this DIY calculator, which takes annoyinglie long…

So, in the end I guess there are 3 options for me now:

  1. Reduce the oats and replace with other carbs
  2. Find a pill with less iron
  3. Don’t worry about the 35mg.


You should be fine, according to this: Health Risks from Excessive Iron

Adults with normal intestinal function have very little risk of iron overload from dietary sources of iron [2]. However, 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, especially if food is not taken at the same time [2,5]. Taking supplements containing 25 mg elemental iron or more can also reduce zinc absorption and plasma zinc concentrations [3,78,79]. In severe cases (e.g., one-time ingestions of 60 mg/kg), overdoses of iron can lead to multisystem organ failure, coma, convulsions, and even death [18,80].

20 mg/kg (gastric upset, etc.) is 1,500 mg of iron if you weigh 75 kg; that’s a hell of a lot. 60 mg/kg (possibly fatal) is 4,500 mg if you weigh 75 kg.

Hopefully 35 mg or you will kill yourself. :fearful: [35 g = 35,000 mg]


Well, it’s not the one-time-overdose that I am worried about, but the upper ammount for daily consumption.

I guess I will just replace a part of the oats with another carb source.

And I also found out that you can find mineral supplements with less iron if you are looking for age 50+. So I just have to find one here that fits.

Thanks for your help…


The iron in animal-based food is more digestible. The iron in plant-based food is largely organically bound, so you don’t absorb it as readily. You don’t need to be concerned about the amount of iron in oats, because you don’t take it up that readily.