What is Chronic Iron Deficiency (Longterm Low Iron)?
Iron is a vital element needed for various body functions. It aids in creating essential proteins like hemoglobin and myoglobin, helps in cell growth, DNA synthesis, and the movement of electrons within tiny energy-producing structures within cells called mitochondria.
Around two-thirds of the iron in the body is found in red blood cells, forming a key part of hemoglobin. Other iron reserves are stored in areas like the bone marrow and liver, and a part of it forms myoglobin and several enzymes that regulate various physiological functions.
If the body’s iron reserves are insufficient to support normal bodily functions, it leads to a condition known as iron deficiency or sideropenia. This is the most frequent nutritional deficiency globally and the top reason for anemia, affecting approximately 2 billion people worldwide.
Iron deficiency can be total (insufficient iron in the body) or functional (where the body is unable to effectively use the available iron). Women in their childbearing years and young children from birth up to 5 years are most at risk.
Diagnosing iron deficiency without anemia is difficult because no well-defined diagnostic criteria exist and the symptoms are unclear. Doctors should suspect a long-term iron deficiency in patients with normal blood count but anemia-like symptoms and low iron storage protein (ferritin). Checking for signs of iron deficiency and potential blood loss in a person’s health history is an important part of investigating these cases.
What Causes Chronic Iron Deficiency (Longterm Low Iron)?
Your body has most of its iron in red blood cells and losing blood through bleeding, anywhere in the body, can lead to iron deficiency. This is actually the most common way for iron deficiency to occur in developed countries. Obvious reasons for losing blood, like vomiting blood, heavy periods, multiple pregnancies, and childbirth, can be identified quite quickly. Other reasons such as hidden gastrointestinal bleeding, infections from hookworms, or donating blood frequently can somehow go unnoticed. Frequent blood donating is a key reason for iron deficiency, especially among women.
Not eating enough iron-rich foods isn’t that common in developed countries. Iron comes in two forms in our diet. We absorb heme iron from animal foods much better than non-heme iron from plant foods. People who are from poorer backgrounds, vegetarians or vegans, or elderly people who don’t eat a balanced diet can all be more at risk of developing iron deficiency. In toddlers, drinking too much milk or juice, using bottles for a long time, and snacking can all contribute to low iron levels.
People with conditions like celiac disease, atrophic gastritis, a certain type of bacterial infection, or who have had certain types of weight loss surgery can have problems absorbing iron. Eating certain things, including tannates, phosphates, phytates, oxalates, and calcium, can also mean less iron is absorbed.
Certain medications can also stop iron from being absorbed properly. These include drugs that reduce stomach acid, antibiotics, levodopa, levothyroxine, and ibandronate.
Chronic diseases such as chronic kidney disease, chronic heart failure, inflammatory bowel disease, certain types of cancer and rheumatoid arthritis can also cause iron deficiency.
Iron deficiency can also be caused by rare inherited conditions such as a mutation in the SLC11A2 gene or IRIDA (iron refractory iron deficiency anemia) caused by a mutation in the TMPRSS6 gene.
Risk Factors and Frequency for Chronic Iron Deficiency (Longterm Low Iron)
Based on the Global Burden of Disease Project by the World Health Organization, iron deficiency has led to 841,000 deaths globally. This health issue is especially common in Africa and some parts of Asia.
In the United States, iron deficiency is seen in 9% of toddlers aged 1 to 2 years. Hispanic toddlers are twice as likely to have this problem compared to white toddlers. It’s also common among teenage girls and women capable of becoming pregnant, with a rate between 9% and 11%. This is particularly prevalent in women from low-income minority populations who have had multiple pregnancies. Among males, around 1% of the population suffers from iron deficiency, though this rises to 2% to 4% in middle-aged and older men.
It’s also worth noting that there’s a connection between obesity and a higher risk of developing iron deficiency.
Signs and Symptoms of Chronic Iron Deficiency (Longterm Low Iron)
Iron deficiency can cause a range of nonspecific symptoms such as:
- General weakness
- Fatigue
- Poor concentration
- Irritability
- Headaches
- Shortness of breath when exercising
- Decreased ability to exercise
These symptoms occur due to reduced amounts of oxygen being delivered to the body’s tissues and a decrease in the activity of iron-based enzymes. Many people with iron deficiency also experience pica or a craving for non-food items like ice, which is rather unique to this condition. Some might also notice symptoms such as dry mouth, hair loss, difficulty swallowing, brittle nails, and restless leg syndrome.
An unusual finding in some people with severe iron deficiency is ‘beeturia’, where urine turns red after eating beets. This symptom is not exclusive to iron deficiency but is more commonly found in individuals suffering from it.
A physical examination of someone with iron deficiency might show:
- Dry skin
- Hair loss
- Atrophic glossitis (a swollen, glossy tongue)
- Cheilosis (cracked skin at the corners of the mouth)
- Pale skin
- Brittle nails
- Spoon-shaped nails
- A systolic murmur (a heart sound heard during a heartbeat)
Testing for Chronic Iron Deficiency (Longterm Low Iron)
Diagnosing iron deficiency involves looking at your medical history, conducting a physical examination, and running laboratory tests. These tests typically include measuring the levels of serum iron, transferrin, ferritin, total iron-binding capacity (TIBC), and transferrin saturation (TSAT).
Serum iron levels can fluctuate throughout the day based on your diet, so it’s best to have a fasting sample taken in the morning. If your ferritin – the protein that stores iron – is below 30 ng/mL, this generally points to iron deficiency.
TSAT, or the amount of serum iron relative to TIBC, is an early marker for iron deficiency and can be useful when the ferritin level isn’t clear cut. If the ratio is below 20%, it can suggest iron deficiency.
It’s important to know that your hemoglobin level, which is the protein in red blood cells that carries oxygen, doesn’t typically decrease until the body’s iron stores are significantly depleted. Therefore, having a normal hemoglobin level doesn’t necessarily mean you’re not iron deficient.
There are additional tests that can help evaluate iron deficiency:
– The soluble transferrin receptor (sTfR) and sTfR-ferritin index: sTfR levels rise in iron deficiency due to an increase in transferrin receptors. This test can help determine if the iron deficiency is absolute, i.e., increased sTfR, or functional, i.e., normal sTfR.
– Zinc protoporphyrin/heme ratio: When iron is low, your body compensates by using more zinc, which leads to an increase in this ratio. This test is preferred over invasive bone marrow aspiration.
– Reticulocyte hemoglobin content: This parameter estimates the availability of iron for red blood cell production a few days before the test. It is a good early indicator of iron deficiency, and serial measurements can also help monitor the body’s response to iron therapy. Inflammation does not affect this measurement, making it useful for determining iron status in patients with chronic kidney disease.
Treatment Options for Chronic Iron Deficiency (Longterm Low Iron)
Patients with iron deficiency who don’t have other health conditions are typically treated with oral iron supplements. These include options like ferrous sulfate, ferrous fumarate, and ferrous gluconate. They are a great option because they are easily available, affordable, effective, safe, and easy to use. It’s important to note that a type of iron called high molecular weight dextran isn’t used anymore due to several severe allergic reactions.
One challenge with oral iron supplements is that they can cause stomach or intestinal side effects in about 70% of patients, which can discourage them from continuing the treatment. These symptoms may be reduced by using special types of iron known as chelated forms. Enteric-coated tablets, which aim to prevent stomach upset, do not work well because they are poorly absorbed in the body.
Iron can also be given intravenously (into the vein) in different forms, such as ferric carboxymaltose, ferric gluconate, ferric or iron sucrose, ferumoxytol, and low-molecular-weight iron dextran. It’s important to monitor the response to IV iron treatment and assess the need for more supplements six to eight weeks after the initial dose.
The risk of allergic reactions to IV iron is low. Giving antihistamines beforehand doesn’t really help to prevent reactions, so they aren’t usually used. However, patients with a history of asthma or allergies to medications should be given steroids before the iron infusion to reduce the risk of any reactions.
Pregnant women are usually given oral iron supplements, especially during the first three months of pregnancy because the safety of IV iron supplementation during this period is not certain. If they are able to tolerate these supplements, that’s great. But, in certain situations, like severe anemia, Inflammatory Bowel Disease or having had bariatric (weight loss) surgery, IV iron is a better option. All types of IV iron are generally safe and effective. However, some variants of ferric gluconate, which contain benzyl alcohol as a preservative, should be avoided because they could harm the fetus.
What else can Chronic Iron Deficiency (Longterm Low Iron) be?
When trying to diagnose iron deficiency without anemia, doctors might face a challenge because most symptoms can also be seen in many other health conditions. These include various reasons for feeling constantly tired, such as fibromyalgia, chronic fatigue syndrome, emotional health issues like depression, long-lasting health problems, and an underactive thyroid, among others. Other possibilities could be conditions that result in unusual cravings to eat items that aren’t food, like psychiatric disorders, eating disorders, malnutrition, as well as conditions causing restless legs syndrome, such as neurological conditions and pregnancy. Therefore, doctors need to consider all these possible diagnoses before finalizing any conclusions.
What to expect with Chronic Iron Deficiency (Longterm Low Iron)
Iron deficiency is a simple condition to treat and usually has great outcomes when there are no complications or other illnesses present.
However, if it’s not properly treated, it can result in significant health issues and even death. It’s particularly risky for older adults and those with ongoing serious health conditions like heart failure and chronic kidney disease.
Possible Complications When Diagnosed with Chronic Iron Deficiency (Longterm Low Iron)
Leaving iron deficiency untreated can have serious negative effects. These can include problems with thinking or cognition, and a reduced quality of life. Not getting enough iron during pregnancy can cause issues for both the mother and the baby. It can affect the baby’s brain development, cause them to be born small and make them likely to also suffer from iron deficiency. For the mother, iron deficiency can often lead to depression, a higher risk of severe infection, and in the worst cases, death.
Iron deficiency has also been associated with worse outcomes for people undergoing heart or abdominal surgery. And for those suffering from heart failure, ongoing iron deficiency can increase the risk of death.
Preventing Chronic Iron Deficiency (Longterm Low Iron)
Patients should be advised to eat foods rich in iron and consume fruits and vegetables high in vitamin C. This will help them meet their daily nutrition needs.
If a baby’s mother has low iron levels, delaying the cutting of the umbilical cord can help prevent the baby from also having low iron.
For infants, after six months of breastfeeding, it’s beneficial to add iron-fortified cereal and formula to their diet. If a child has a parasitic infection, they should be given medication to treat the condition. In areas with a high rate of iron deficiency, it’s recommended that women who are of reproductive age take daily iron supplements. These measures can help prevent iron deficiency.
