THE DARK SIDE OF IRON INFUSIONS

Iron deficiency is seen in almost one third of the population, with it occurring more often in women than men; 1 in 7 women between the ages of 15 and 50 are anaemic. Iron is essential for our oxygen transportation, oxygenation of muscles, supporting the mitochondria, as well as DNA synthesis. It’s no wonder we feel out of breath and super tired when iron levels plummet! One of the main reasons iron deficiency is more common in women than men is because we have our monthly bleed, which increases our iron losses. We also must consider our consumption of iron and our iron absorption. Let’s explore these and then understand the influences of our choices in iron repletion so we can make the best decision for us. What affects the amount of iron we have available?

1 - Iron intake

Haem sources are considered to be best absorbed (chicken liver and beef liver, beef, lamb and sardines). Non-haem sources such as soybeans, blackstrap molasses, lentils, cooked spinach, tofu/tempeh, chickpeas, lima beans and black eye peas will contribute iron to the body, though may not be as readily absorbed. 

Recommended dietary intake of iron is 18mg for non-pregnant, non-lactating women. A serving of steak (100g) will provide around 2.5-4mg of iron and a tin (100g) of sardines will provide around 3mg of iron. We collect iron in many foods throughout our day, so we don’t need to just focus on haem sources, though these are appreciably one of the best ways to sustain iron stores (without supplementation).

2 - Iron absorption

To support absorption, we want to avoid tannins near our meals (i.e. tea and coffee, but also in some herbs!) and calcium-containing foods/supplements as these interfere with iron absorption. Including vitamin C foods can assist with absorption. It’s also important to know that our overall gut health and intestinal integrity play a huge role in our absorption of iron. Digestive issues are worth exploring if there are gut symptoms present alongside chronic iron deficiency. 

A note on hepcidin:

Our body’s iron homeostasis is governed by the hormone hepcidin. Hepcidin levels control iron absorption and release into the bloodstream. As hepcidin increases, absorption decreases, and as hepcidin decreases, absorption increases. Hepcidin increases in the presence of high levels of iron (e.g. supplementation) and any kind of infection or inflammation in the body, thus blocking absorption of more iron. Hepcidin will ordinarily decrease in states of low iron consumption and deficiency. After high dose iron, hepcidin can remain high for up to 24 hours, blocking further iron absorption as a protective mechanism.

3 - Iron loss

As discussed above, women with a regular menstrual cycle have monthly losses of iron. The level of iron loss is largely dependent on the volume and length of the menstrual bleed. Anything over 80mL (approx. 6.5 filled super tampons or 8 filled super pads) is considered a heavy period, and so investigations are worthwhile. 

More rare, but to be considered is any internal bleeding from a peptic ulcer or haemorrhoid (for example). High losses can also be from excessive vigorous exercise. Athletes require more iron as they have increased oxygen needs and have greater production of red blood cells as a result.

4 - OTHER

Ideally, if a woman has a normal bleed, is eating adequate haem iron and has robust gut health, is not an athlete etc then iron stores ought to be maintained relatively easily. If this isn’t the case, then there are a few other considerations:

- Inflammation/chronic infection. During infection, autoimmune flares, and any inflammatory response, the body essentially responds by decreasing iron availability in the blood. It does this by increasing hepcidin to halt absorption and also scurries iron away. 

- Nutrient deficiencies. Having adequate levels of iron supporters (e.g copper, vitamin A…) is also part of the picture of iron deficiency—it’s not just about iron!

- Bacteria sequester iron. There are particular bacteria (like e. Coli) that require iron for their growth and proliferation. In this way, bacteria have mechanisms in place to acquire iron from our cells. The body will also put steps in place to inhibit this, directing iron away from the bloodstream (reducing free iron). Though it becomes a battle between bacteria and the body. 

Repleting iron

Iron infusions

Iron infusions can release 1000mg of iron into the bloodstream in 15 minutes. We then might see ferritin levels at ~400ug/L in bloods 2 weeks later. It can stay high for months. Please note >150ug/L is considered iron overload in women.

Cost: 

• Increases oxidative stress in the body, linked to cellular and tissue damage

• Caution for any autoimmune diseases because of iron overload

• Decreased immune response to infection during iron overload

• Post-infusion reaction symptoms such as muscle aches, fever, nausea etc

Benefit:

• Fast (can take 3 months to replete anaemia with supps)

• Efficient (bypass need for optimal absorbability/oral absorption issues)

High dose iron supplements

100mg elemental iron, found in most high dose iron supplements, is also a fair wad of iron, considering we can only absorb up to 15mg a day.

Cost: 

• Prolonged high dose iron can also cause oxidative stress

• If not dosed appropriately, can impact hepcidin, decreasing absorption

• High level unabsorbed iron, leading to gut disturbance and constipation

• Changes microbiome toward dysbiosis and increases reactive oxygen species in the gut, impacting GI integrity and upregulating inflammation

Benefit:

• Not as high dose as IV/injection (theoretically better for autoimmune and inflammatory conditions)

• Repletes iron stores within 3 months (ordinarily)
  

Lower dose bisglycinate iron supplements

A lower dose of around 24mg elemental iron could be better, if absorption isn’t the issue. 

Cost: 

• Potential slower repletion

Benefit:

• Reduced negative GI effects like constipation

How to decide on next actions

Thorough analysis of full iron studies (iron, transferrin, saturation, and ferritin) is important for any form of prescription iron. So, understanding what’s happening with iron regulation in the body ought to be the first step. Additionally, understanding why iron is bottoming out and having a plan in place to rectify the situation is a pretty good idea. Whilst an iron prescription could be warranted, it is good to question whether there is a need for fast repletion, what the cost/benefits are of supplementing, and caution is wise in inflammatory and autoimmune conditions. 

Prolonged iron consumption, and/or regular infusions might not be the best for our health long term. I implore you to delve deeper into the why behind the deficiency and question whether an infusion—even supplementation—is absolutely required. Nutrition adjustments could make a huge difference if the focus hasn’t been here, for example.