Symptoms of Iron Deficiency

Symptoms of iron deficiency

Verywell / Jiaqi Zhou

Iron deficiency occurs when you do not have enough of the mineral iron in your blood. If it isn't treated, it can lead to iron deficiency anemia which is a decrease in the number, size, and function of red blood cells.

Athletes, particularly women, are commonly iron deficient. Iron is vital for athletic performance as it aids in the transportation of oxygen to your cells. It also is important for brain health and immune function. Knowing the symptoms of iron deficiency can help you prevent it from getting worse and turning into anemia.

Symptoms of Iron Deficiency

Iron deficiency can cause several symptoms that can worsen as the deficiency develops. Look for these symptoms of low iron levels to prevent iron deficiency anemia.

  • Tiredness
  • Weakness
  • Poor concentration and memory
  • Dry skin and brittle nails
  • Heart palpitations
  • Shortness of breath
  • Greater infection risk or recurrence
  • Headaches and dizziness
  • Feeling cold
  • Restless leg syndrome
  • Red, inflamed tongue (glossitis)
  • Abnormal cravings for dirt, metal, paper, or starchy food (pica)

Low iron affects your brain since it is necessary for the oxygen that is transported there. Low iron levels can cause poor concentration, as well as irritability. It leads to feelings of fatigue, a prevalent symptom due to the body’s cells' lack of oxygen. Frequent infections may occur with low iron levels since the mineral is necessary for healthy immune system function.

Iron Deficiency in Female Athletes

Iron deficiency is a common health concern for female athletes. The condition is common for active women as iron is necessary for athletic performance. Iron is a part of the hemoglobin in your red blood cells that helps transport oxygen and remove carbon dioxide from your cells.

Iron deficiency is common in female athletes because of:

  • Physical Activity: Physical activity—especially frequent and high-intensity training—increases your body's demand for iron.
  • Menstruation: Menstruation also requires additional iron. Low iron levels can lead to heavier periods, leading to increased iron loss, which becomes a vicious cycle.
  • Sweating Heavily: Sweating due to activity and heat can lead to mineral losses, including iron.
  • Dietary Choices: Athletes may have specific dietary needs based on their activity levels. In general, athletes require more iron. Avoiding red meat can also lead to inadequate iron levels in the diet and increases the risk of iron deficiency. 

As an athlete, if you have iron deficiency, you may experience a loss of endurance, a higher than usual heart rate while exercising, reduced performance and power output, recurring injuries, illnesses, and mood changes.

Daily Iron Requirements

The daily recommended iron allowances (RDA) depend on your age, gender, and diet. If you do not eat meat, you should aim for 1.8 times more iron from food than the RDA. This is because heme iron, the type you get from meat, is much more absorbable than non-heme iron, or the kind you get from plant-based foods.

There are currently no iron requirements for female endurance athletes. However, some researchers believe that female distance runners, in particular, require approximately 70% more iron than the RDA. 

Recommended Daily Intake of Iron for Adults
Age Male Female Pregnancy Lactation
14-18  11mg 15mg 27mg 10mg
19-50  8mg 18mg 27mg 9mg
51+  8mg  8mg

If you are a female athlete, you may require additional iron. Speak to your health care provider to see what is best for you.

Food Sources of Iron

Meat, including red meat, poultry, and seafood, are sources of heme iron. This animal-derived form is the most bioavailable type of iron. Plant sources provide non-heme iron. In the United States and Canada, grain products like flours, bread, and cereals are fortified with iron, providing about half of the daily requirements.

Here are some of the top iron-rich foods:

Consuming a low-carb diet can lead to iron deficiency, as a large percentage of the iron in a typical diet comes from fortified grains.

Tips for Enhancing Iron Absorption

Combining iron-rich foods with those that are high in vitamin C, such as citrus fruits, will enhance iron absorption. In addition, consuming animal sources of heme iron along with plant-based sources can increase the absorption of non-heme iron.

It is worth knowing that the phytates (found in grains and beans) and some kinds of polyphenols (found in plant-based foods like cereals and legumes) can decrease non-heme iron absorption. 

Another mineral, calcium, binds with iron and can inhibit the absorption of non-heme and heme iron. For this reason, it's best to avoid consuming iron-rich foods with calcium-rich ones such as dairy products if you struggle with getting enough iron in your diet.

Taking Iron Supplements

Iron supplements can be a convenient and effective way of avoiding or eliminating iron deficiency. There are many types of iron supplements, including those that come as a multivitamin and multi-mineral joint supplement or iron-only supplement. 

Typical forms of iron found in supplements are ferrous and ferric iron salts. Ferrous iron is more bioavailable than ferric iron. Many supplements that only contain iron provide more than the daily value. Most iron supplements include vitamin C to improve absorption. It is wise to also look for a supplement that does not contain calcium.

The U.S. National Library of Medicine recommends taking iron supplements on an empty stomach. It may take two months of consistent supplementation for your blood count to reach a normal level of iron. It may take an additional 6 to 12 months to increase bone marrow iron stores.

Common side effects of high iron intake due to supplements include nausea, cramping, diarrhea, and constipation. Although it is recommended to take iron supplements on an empty stomach, you might wish to take them with some food if you have these side effects. Avoid foods high in fiber or caffeine at the same time as taking iron supplements.

A Word From Verywell

Iron deficiency is a common health concern, especially for women. If you are active, the likelihood of low iron levels is even greater. If you feel unusually tired or are experiencing any of the other symptoms of iron deficiency, speak to your health care provider.

Consuming a diet rich in iron, including heme iron, is best for avoiding deficiency and anemia. If you struggle to get enough iron in your diet, a supplement may be appropriate.

9 Sources
Verywell Fit uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Rachel MacPherson, BA, CPT
Rachel MacPherson is a health writer, certified personal trainer, and exercise nutrition coach based in Montreal.