When to take Iron | PlanYourVitamins.com

What is iron good for?

Short answer: Iron has potential benefits for blood health, energy levels, athletic performance, pregnancy and cardiovascular health.

Iron is an essential mineral that plays a vital role in our health, as it is required for the protein hemoglobin to be able to perform its function of transporting oxygen throughout the entire body via the blood, making it crucial for both mental and physical performance.

Iron deficiency

It goes without saying that a deficiency in iron can cause a wide range of health conditions, which vary in severity depending on the level of iron deficiency. The main problem is that a low level of iron is not easily detectable in its early stages, as symptoms like tiredness, reduced stamina, increased irritability or poor concentration can often be disregarded as unimportant, or mistakenly attributed to something else entirely.

Iron deficiency is relatively common, and roughly 10 million people in the US alone are reported to have low iron levels. Some examples of people who are more at risk of being deficient in iron are pregnant mothers, women who experience heavy menstruation, infants, cancer patients, people who suffer from heart failure, people who suffer from gastrointestinal disorders that could affect iron absorption, people who follow a vegetarian or vegan diet, and also people who are frequent blood donors.

Iron becomes even more important during pregnancy due to the dramatic increase in blood cell production and oxygen supply requirements for the fetus.

If left untreated, low levels of iron can develop into a more serious condition known as iron deficiency anemia, in which your blood simply no longer contains enough oxygen for your body to function in a healthy manner. This can lead to both mental and physical fatigue, and increased susceptability to illness.

Importance for pregnancy and athletic performance

As mentioned above, iron levels are of particular importance during pregnancy, due to the way in which blood cell production increases dramatically in order to maintain the fetus supplied with oxygen, which means that there is a considerable increase in the demand for iron in the mother's body. If this demand is not met, there is a risk to both the physical health and cognitive health of the infant, as well as the immune system of the mother.

Although changes to diet and lifestyle are often recommended to address any iron deficiency, iron supplements are often the preferred method, as they can produce results much quicker.

Interestingly, iron deficiency is more common among athletes than in people who aren't very physically active, and especially in young female endurance athletes, such as marathon runners. Doctors recommend that these athletes increase their iron intake by an additional 10mg above the RDA.

Excessive iron intake

With all that said, you may be feeling the urge to take some iron supplements right now as you have been reading this, but it is important to understand that an excess of iron can also cause health problems, some of them quite serious, including cell damage or even organ failure.

In fact, it is often recommended to avoid taking iron supplements together with vitamin C supplements for example, because vitamin C can actually increase the amount of iron that your body absorbs, leading to excessive iron intake.

So, if you are suffering from any of the symptoms commonly associated with iron deficiency, check with your doctor first, and they will be able to test your blood for iron deficiency, and give you the green light for taking iron supplements if necessary.

When should I take iron?

Short answer: Iron is best taken first thing in the morning on an empty stomach, at least 30 minutes before breakfast.

Iron is best absorbed when taken between meals, on an empty stomach, either with a large glass of water, or alternatively with some fruit juice due to its vitamin C content, which can optimize iron absorption. However, if you find that this causes any stomach upset, you can take iron at or around mealtime instead.

There does not appear to be a particular time of day that is best suited for taken iron, so you can incorporate it into your routine whenever suits you best.

What should I avoid taking iron with?

Short answer: Avoid taking iron supplements at the same time as calcium, copper, glycine, green tea extract, manganese, multivitamin, vitamin C, zinc, antacids, caffeine or dairy products.

Avoid with calcium

It is recommended to avoid taking iron and calcium supplements together, as calcium is known to interfere with the body's ability to absorb iron properly. Even non-supplemental amounts of calcium, such as that found in dairy food, can inhibit iron absorption.

Avoid with zinc, copper or manganese

Iron in turn is known to inhibit the absorption of other minerals, such as zinc, copper and manganese, so avoid taking these at the same time as iron.

Avoid with green tea extract

Green tea, or more specifically within the context of supplements, green tea extract, is also known to inhibit iron absorption due to the way in which some of the antioxidants found in green tea bind to iron, so it is best to avoid taking these types of supplements together, as this binding can negate the benefits of both supplements.

These extracts often have caffeine in them, which is also known to interfere with iron absorption.

Avoid with vitamin C or glycine

At the other end of the spectrum, we need to exercise caution with absorbing too much iron. Specifically, glycine and vitamin C are known to significantly increase the amount of iron absorbed by the body, so it is advised to not take iron supplements together with these supplements.

To get an optimal amount of iron from your iron supplement, it is recommended to take it with a drink that that has a relatively moderate amount of vitamin C instead, such as fresh orange juice.

With dairy products or antacids

As mentioned above, avoid taking iron supplements with anything else that contains calcium, including dairy products, or any antacid medication that includes a form of calcium as an ingredient, as calcium can inhibit iron absorption.

With caffeine

Caffeine is also known to reduce the body's ability to absorb iron.

What are natural sources of iron?

If you are interested in achieving your daily iron intake through your diet, rich sources of iron include:

Beef liver
Beef
Lamb
Clams
Oysters
Mussels
Shrimp
Tuna
Eggs
Spinach
Sweet potatoes
Legumes
Broccoli
Dark chocolate
Tofu

Iron data sources & further reading

Last updated by Asklepios on 30th January, 2025