What it is
Iron is an essential mineral.
What it does
Iron is primarily important as a component of hemoglobin (which carries oxygen around your body) and myoglobin (which stores oxygen within your cells). It also has roles in normal growth and development as well as reproductive function.
The recommended intake for iron is 11mg per day for men and postmenopausal women. The recommended intake for non-pregnant women who haven’t reached menopause is 18mg. Pregnancy can increase intake requirements for iron.
The safe upper limit for iron intake is 45mg per day.
Likelihood of tracking completeness: Very high in the US and Canada, and low in many other places.
Nutrition labels in the US and Canada are required to list iron content. So, the vast majority of American and Canadian foods in the MacroFactor database should contain iron information, making it easy to accurately track your iron intake with consistent food logging.
However, in the EU, Australia, and many other countries, iron is a nutrient that is only reported on a voluntary basis. Many food manufacturers do not voluntarily list iron content on nutrition labels, so many branded products in the MacroFactor database from outside the US and Canada lack iron information. So, if you’d like to accurately track your iron intake, you’ll need to make a point of mostly tracking “common foods,” which come from research-grade databases that have full nutrient reporting.
For more on when you can track using branded foods versus common foods when you’re trying to accurately monitor your intake of particular nutrients, you should check out this article.
Likelihood of insufficient intake: Pretty low for men, and pretty high for premenopausal women
Most men in developed countries consume adequate amounts of iron. However, most premenopausal women need a bit more iron than men due to blood loss during menses, but they tend to consume a bit less iron than men. So premenopausal women have higher rates of iron insufficiency than other demographic groups. Vegetarians and vegans also have elevated rates of iron insufficiency because many iron-rich foods are meat products, and heme-bound iron in meat has greater oral bioavailability than plant sources of iron.
For more on nutrients with a greater likelihood of insufficient or excessive intake, you should check out this article.
Signs of deficiency
The classic sign of iron deficiency is microcytic, hypochromic anemia – low hematocrit characterized by red blood cells that are smaller and less red than normal due to lower hemoglobin content. However, the early warning sign of iron deficiency is a decrease in serum ferritin concentrations, which can be detected in blood tests, and which occurs well before anemia sets in.
Signs of anemia include weakness, fatigue, decreases in exercise performance, poor body temperature regulation, and decreases in cognitive function.
Most meat is a good source of iron, both in terms of iron content, and how easily the iron can be absorbed. Shellfish are particularly rich in iron. Vegan sources of iron include green leafy vegetables, asparagus, kelp and algae (like nori or spirulina), and beets. Many grain products are also fortified with iron.
If you’d like to learn more about micronutrients generally, there’s a five-part series on the MacroFactor website you might enjoy.