Iron supplements - friend or foe?

Do I need an iron supplement? This is a common question I get asked from people! Let’s dive deep into iron.

Firstly, have you ever been prescribed an iron supplement? Let me guess, you experienced constipation, black stools and maybe even abdominal discomfort? Not pleasant at all, and I am here to tell you why. 

Iron, although an essential mineral, has been over prescribed for many years. When a person is low in iron, it is natural to think, let’s just supplement….. but let’s take a step back and look at why you are low in iron in the first place: 

Are you getting enough iron in your diet? 

Are you getting your dietary iron from animal or plant sources? 

  • Are you eating plenty of iron but not absorbing it effectively? Maybe you have low stomach acid? 
  • Are there sneaky bugs in your gut eating your iron? (think SIBO & other bacterial overgrowths) 
  • Is underlying inflammation skewing your iron results?
  • Do you have undiagnosed coeliac disease? 
  • Maybe you’re losing too much blood via menstruation? 

These are all common causes of iron deficiency. Each person will have a different why. 

Yes, supplementing is sometimes necessary, however if you haven’t got to the bottom of why you are iron deficient then you may find yourself on and off iron supplements for the rest of your life. 

Now comes the iron supplements. Most iron supplements found on the shelf at supermarkets and pharmacies contain around 100-105mg of elemental iron. In terms of iron uptake, the body can only absorb approximately 20mg of elemental iron within a 48hr window. If you are taking an iron supplement that contains 100-105mg of iron, the other 80-85mg circulates around your bloodstream until it is excreted via your stools (this is why your stools will often appear black & tarry). When this much iron is freely circulating around your bloodstream (and not being absorbed), it causes oxidative stress which contributes to inflammation over a longer period of time. 

As absorption can take around 48hrs, it can be beneficial to supplement iron every second day as to not overwhelm the body with too much iron. In saying this, 100-105mg of iron is excessive which is why it is important to consult a health professional, such as a degree qualified Naturopath or Nutritionist to get the right supplement for you. 

Some other things to consider when increasing your iron either through supplementation or diet: 

  • Tannins inhibit the absorption of iron. Tannins are most commonly found in coffee & tea so take your iron supplement away from your coffee!
  • Vitamin C enhances the absorption of iron. Most iron supplements contain vitamin C however it is beneficial to consume dietary sources of iron alongside a source of vitamin C. For example a squeeze of lemon juice (rich in vitamin C) over green leafy vegetables (plant source of iron). 

Lastly, your iron status is not determined by ferritin alone. Ferritin is only one marker of your iron status. When requesting iron studies from your doctor, ensure they are testing your serum iron, transferrin, saturation & ferritin. A full blood count (which includes hemoglobin) alongside your iron studies is also important to ensure you are not anemic. 

Some tips for getting your iron tested:

  • Fast for no more than 8 hrs prior to getting your blood test – first thing in the morning (before breakfast) is a good time
  • Ensure you are hydrated prior to getting your bloods taken 
  • Avoid getting your iron tested when you are sick (cold, flu, COVID etc.) as this can skew your results
  • Avoid getting your iron tested after strenuous exercise 

If you’re someone who has persistently low iron & would like to get to the bottom of it, I would love to help!