Iron: Why It Matters
Iron & Your Energy: Why It Matters More Than You Think
Iron deficiency is one of the most common nutrient deficiencies worldwide, particularly in women of reproductive age, teenagers, and people with digestive conditions that impair absorption. While low iron can be debilitating, taking iron supplements without testing can be just as dangerous, as too much iron carries its own set of risks. Let’s look at why iron is so important.
What Iron Does in the Body
Iron is an essential mineral that enables your body to produce haemoglobin, the protein in red blood cells that transports oxygen from your lungs to your tissues. It is also a component of myoglobin, which helps muscles store and use oxygen efficiently. Iron plays a key role in energy production within mitochondria, supports neurotransmitter synthesis for mood and cognition, support thyroid function (conversion of T4 to the active T3 thyroid hormone), and the immune system’s ability to fight infection. Without enough iron, every cell in the body struggles to perform, leading to fatigue weakness, poor concentration, and increased susceptibility to illness.
Why Iron Deficiency Happens
Iron deficiency develops for several reasons.
Women with heavy or irregular menstrual bleeding
Pregnant and breastfeeding women whose demands for iron are significantly higher.
Children and teenagers may become deficient during growth spurts, and dietary choices also play a role
Restricted diets: vegetarians and vegans may struggle to obtain adequate iron if their diets
Gut health: conditions such as coeliac disease, inflammatory bowel disease, or even low stomach acid can also impair iron absorption
Signs and Symptoms of Low Iron
Because iron supports so many processes, deficiency shows up in diverse ways. The most common symptoms include persistent fatigue, pale skin, brittle nails, hair thinning, and a lowered tolerance to stress. Some people experience headaches, dizziness, restless legs, or shortness of breath. Low iron can also impact mood and cognition, contributing to brain fog, irritability, and even depression. These symptoms are non-specific, which is why testing is so important before starting supplements.
Dietary Sources and Types of Iron
Not all iron is created equal. There are two main dietary forms: haem iron and non-haem iron.
Haem iron: found only in animal foods such as red meat, poultry, and fish, is absorbed more efficiently by the body, with an estimated bioavailability of 15–35%.
Non-haem iron: present in plant-based foods such as lentils, beans, spinach, pumpkin seeds, quinoa, and tofu, is less efficiently absorbed, with bioavailability often between 2–20% depending on other dietary factors.
The body absorbs haem iron more directly because it is carried into the intestinal cells as part of the haem molecule. Non-haem iron, however, requires conversion from the ferric (Fe³⁺) to the ferrous (Fe²⁺) form before it can be absorbed, a process that depends heavily on stomach acid and dietary enhancers such as vitamin C.
Increase iron absorption: Cooking in cast iron pans, soaking and sprouting legumes, and combining iron-rich meals with vitamin C–containing foods can significantly improve absorption.
Decrease absorption: Substances like tannins in tea and coffee, calcium in dairy products, and phytates in unsoaked grains can inhibit non-haem iron uptake.
Supplements and Why Testing Matters
When diet alone is insufficient, supplementation may be required. However, iron is not a nutrient to take blindly. There are multiple supplemental forms, each with different absorption rates and side effect profiles.
Ferrous sulfate: the most commonly prescribed but is often associated with gastrointestinal upset such as constipation or nausea.
Ferrous gluconate and ferrous fumarate: may be better tolerated.
Iron bisglycinate: a newer chelated form, whichs tends to be absorbed more efficiently with fewer digestive issues.
Pathology testing is essential before supplementation. Standard iron studies measure ferritin (the main storage form of iron), serum iron, transferrin saturation, and haemoglobin. Low ferritin is one of the earliest indicators of deficiency, while high ferritin may point to inflammation or iron overload. This is important because excessive supplementation can cause iron toxicity, leading to oxidative stress, liver damage, and increased risk of chronic disease. Some people also carry the genetic condition haemochromatosis, which causes excessive absorption of iron; for them, supplements could be harmful.
Hepcidin: The Iron Gatekeeper
One of the reasons iron management can be tricky lies in the hormone hepcidin, which regulates how much iron is absorbed from food and released from storage. When hepcidin levels are high, such as during inflammation, infection, or after taking large iron dose, absorption from the gut is blocked. When hepcidin levels are low, absorption is enhanced. This is why inflammation-related conditions can make it difficult to restore iron levels despite supplementation.
In addition, hepcidin follows a diurnal (daily) rhythm, rising during the day and peaking in the afternoon and evening, while being lowest in the morning. This means that iron taken in the morning is generally absorbed better than iron taken later in the day. For this reason, it is generally recommended to take iron supplements in the morning, on an empty stomach if tolerated, alongside vitamin C–rich foods or drinks. Avoiding tea, coffee, or calcium-containing foods for at least an hour around your supplement can also make a significant difference.
Naturopathic Strategies for Healthy Iron
Ideally, the goal is always to support iron levels naturally where possible. This means building meals around iron-rich foods, pairing them with vitamin C sources, and supporting the gut to optimise absorption.
Identifying the underlying cause of iron deficiency is paramount. While supplementation or even iron infusions can sometimes be necessary to restore levels quickly, they are not a long-term solution if the root issue remains unresolved. Ongoing reliance on iron without addressing why deficiency occurred in the first place can mask deeper problems, such as heavy menstrual bleeding, poor dietary intake, gut inflammation, celiac disease, or chronic infections. Supporting the root cause not only helps prevent recurrence but also ensures the body can regulate and absorb iron more effectively.
When to Seek Help
If you suspect low iron, test, don’t guess. The safest approach is to seek a blood test and work with a practitioner who can interpret your results in the context of your health history.
A comprehensive naturopathic approach, focuses on digestion, inflammation, menstrual health, and overall nutrient balance.
