Iron is important for the binding of oxygen to hemoglobin (on red blood cells) and is necessary for the transport of oxygen and so energy production; it is also important for the immune system. Prolonged iron deficiency is associated with anemia (iron deficiency anemia is the most common form of anemia), so the general symptoms of iron deficiency are often associated with increased fatigue, but it is also associated with a dysfunction seen in muscles, skin, mucosa, hair, and nails for example.

In addition to the low supply of iron (by an unbalanced diet with low absorbable iron content), there may also be the reabsorption disorder caused by inflammatory bowel disease, or an infection (as with the bacterium Helicobacter pylori or other causes of atrophic gastritis). In addition, a longer-term intake of drugs (such as antacids against excessive stomach acid production) may be the cause of the deficiency. Certain foods can also reduce the iron resorption (see below), but such foods are usually relevant only if there is already too little iron in the diet anyway and/or if there is an increased demand for iron for other reasons.

The normal iron requirement is about 10 - 12 mg/day, in women with a menstrual period at about 15 mg/day, pregnant women at 30 mg/day and nursing women at 20 mg/day. Vegetarians and vegans can achieve this through a well-balanced diet, but it is more difficult for them since the plant foods contain iron in a different binding form that is significantly less absorbed. Here it is very important that the food contains whole grains, legumes, seeds, and nuts as well as increasing the absorption-promoting factors as well as reducing absorption-inhibiting factors (see below).

To assess the iron supply and the iron metabolism, different parameters can be measured in the laboratory: the iron blood serum value and the transferrin (transport protein of the iron) and the iron needed for blood formation (soluble transferrin receptor) as well the ferritin (which allows estimating the stored iron). Inflammatory parameters (CRP) and other factors are also used for the differential diagnosis of chronic iron deficiency.

From Meat and Fish is absorbed much more iron than from vegetable foods

It should be noted that some vegan foods, even if they have higher iron content, only a small fraction of the plant's iron-binding form is absorbed (on average only 3-5%). From meat and fish is absorbed much more iron (about 20% on average).

You can increase iron absorption from vegetable foods

1. The absorption of iron can be achieved by the simultaneous administration of vitamin C-rich foods, e.g. paprika, parsley, berries or fruit juices are improved.
2. The simultaneous consumption of meat increases the iron absorption also from plant foods.

At mealtimes 1-2 hours before and 3-4 hours after, are separated calcium- and oxalic-rich foods from iron-rich foods.

Factors that worsen iron absorption

Foods that contain a lot of calcium or a lot of oxalic acid reduce the amount of iron absorbed from foods. If you want to absorb more iron from foods, you should consume on certain days calcium or oxalic acid rich foods only with a time lag to the iron-rich foods (see above).

• for calcium, this mainly affects dairy products
• the largest content of oxalic acid include: purslane, cassava, amaranth, spinach, rhubarb, yams, beetroot, sweet potatoes (depending on the species), chard, peanuts, almonds, sesame with shell, cocoa (chocolate)

Tea also contains a lot of oxalic acid, but 1-2g of tea leaves per 100ml of water is less effective, especially if the tea does not last more than 2 minutes in the hot water; and with coffee is the same as tea (coffee has slightly less oxalic acid compared to tea) significantly more oxalic acid has instant coffee powder.

Key points in summary:

Consume 1-2 times a week meat (preferably low-fat poultry meat) and 1-2 times fish a week; otherwise abundant whole grains and legumes as well as lots of fruits and vegetables and herbs.

• Do not consume calcium-rich foods, such as dairy products, 2 hours before and 3 hours after the meat or fish.

• Consume vitamin C-rich foods with meat or fish meal - as well as with whole grain and legume products

>> preferably a tomato juice or orange juice; or acerola juice

>> Salad with red pepper with parsley

>> Mixed fruit salad for dessert (with berries, kiwi, papaya, etc.) Blackcurrant is the leader in vitamin C and many other valuable nutrients (“Super Food”).

Note: Some foods, such as liver or kidneys contain a lot of iron, but the frequent consumption of "offal" can lead to unfavorable other factors.

Iron with a vegetarian or a purely vegan diet