Iron and zinc are vital nutrients involved in many processes in the body, but both take on a more important role when you are thinking about having a baby. We often hear the need for women to maintain adequate iron intake, but did you know when iron is low, zinc is often simultaneously low, and vice versa?
Both nutrients share very similar functions. Zinc helps to produce new red blood cells, while iron brings oxygen to these red blood cells. Both iron and zinc are of particular importance during the preconception period and pregnancy, due to their influence on the growth and development of your baby. A deficiency in either nutrient has been found to cause similar effects, such as stunted growth, impaired physical and neurological development and an increased risk of pregnancy complications.
How absorption and digestion of iron and zinc occur
Whilst deficiencies of these minerals often co-exist, they compete with each other for absorption. When we eat foods containing nutrients, our body starts the digestion process. This is where our digestive system slowly breaks down the food to allow the absorption of nutrients. Enzymes (which are types of proteins that help to start chemical reactions in our body) help to break down our food and absorb nutrients. Zinc is found in some of the enzymes that help to absorb iron, so a deficiency in zinc has been shown to prevent the absorption of iron in our intestines, potentially contributing to iron deficiency.
Zinc also competes with iron for absorption in our intestines. This means that when you have eaten a meal or if you have taken an iron and zinc supplement together, both nutrients will fight to be absorbed in your intestine. One nutrient will always win, causing the other nutrient to be absorbed a little less.
How to know if you have an iron or zinc deficiency
Zinc deficiency is often characterised by a loss of appetite (which may result in unexplained weight loss), poor wound healing and a weak immune system. It can be hard to test for zinc deficiency. This is because zinc is only found in small amounts within our cells, meaning a simple blood test cannot always accurately detect zinc levels in our body. The best way to determine your zinc levels is by visiting an accredited practising dietitian, who will be able to analyse your dietary zinc intake.
In comparison, iron deficiency can easily be diagnosed through a simple blood tests ordered by your doctor. Signs of iron deficiency usually include a lack of energy caused by a lack of oxygen getting to your cells, pale gums and eye sockets, and ‘spoon-shaped’ finger nails. Deficiency in one of these nutrients may be an indicator of a deficiency in the other, making it important to monitor and test both levels when you’re trying to conceive or are pregnant.
Food sources of iron and zinc
Now let’s look and zinc and iron deficiency from a dietary perspective. Both nutrients have very similar food sources. Meat, poultry, fish, legumes, soy products and wholegrains are all rich in both zinc and iron. This can mean that if these foods are not a regular component of your diet, you could be at risk of a deficiency in both nutrients.
So, if your health care professional suspects that you are low in one of these nutrients, make sure that you ask them about the other!
Published August 2022
Author: Melanie McGrice – Advanced Accredited Practising Dietitian.
Melanie McGrice is a highly respected Australian dietitian, passionate about working with women to improve nutrition and dietary issues. Melanie is also the director of Nutrition Plus, a dietetic company which specialises in fertility, pregnancy and women’s health.