Hi Jurgen,
I can see how this can be a bit alarming. So I'll try to answer your question and give some additional information about why Jake provides the amount of iron it provides. Some background first:
Iron is an essential mineral. We need iron as a building block of a couple of very important proteins in our body. One of those proteins is haemoglobin, a protein in our red blood cells that carries oxygen through the body. Which explains why one of the symptoms of iron deficiency is fatigue: Energy production requires oxygen, and when insufficient oxygen is distributed to our cells, we can't produce enough energy.
So, red blood cells have iron contained in haemoglobin protein. This is called heam-iron - which is relevant to our story. When you eat steak, you consume a good amount of haem-iron. Iron in our food that isn't contained in haemoglobin is conveniently called non-haem iron. The iron we get from spinach, for example, is non-haem iron. This form of iron, non-heam iron, isn't absorbed very well by our body.
How much we need
The PRI for iron is 11 mg/day (EFSA). PRI stands for Population Reference Intake. This is the amount that is adequate (enough) for 97.5% of the population. EFSA hasn't set an upper limit but mentions 50-60mg/day as the amount at which symptoms of excess start to occur. The IOM (US counterpart of the EFSA) did set an upper limit: 45mg/day of iron. With this recommendation, the IOM also states the following:
"Non-heme iron absorption is lower for those consuming vegetarian diets than for those eating nonvegetarian diets. Therefore, it has been suggested that the iron requirement for those consuming a vegetarian diet is approximately 2- fold greater than for those consuming a nonvegetarian diet. Recommended intake assumes 75% of iron is from heme iron sources."
The absorption of non-heam iron is lower than the absorption of haem-iron. As Jake is vegan, the iron in Jake is non-heam. Which means we need a bit more of it to offset the lower rate of absorption of its iron. That's why Jake provides about double the amount of iron. Please note that even if the iron in Jake was higher it would still be well below the upper limit.
Excess regulation
Our body regulates the amount of iron that it absorbs and distributes. When we have too little iron in our body, our body absorbs more iron and distributes the iron it has to the places that need it most. In the case of excessive iron in the body, it's the other way around. This way, the body iron content is linked to demand.
As long as we stay within sensible boundaries, we don't have to worry about iron overdose. However, people with the inherited condition hemochromatosis have trouble regulating their iron absorption. In such cases, as mentioned by @Scottoboe, you'll have to help your body do its job by keeping record of the amount of iron in Jake/any foods you eat.
Besides the control mechanisms of our bodies, the absorption rate of iron can also be affected by e.g. the presence of vitamin C, as @Scottoboe mentions. This effect is limited and is also counteracted by the presence of e.g. calcium and phytic acid from the oats in Jake, which both inhibit the absorption of iron.
I hope this helps. Let me know if you have any questions unchecked. Also, check out about our blog regarding iron here.
