Iron deficiency & female athletes

Posted on Oct 19, 2020 By Valentina Duong Valentina Duong

Feeling tired and struggling to push through your training sessions? It may be simply fatigue build-up from training and lifestyle stress, but it could also be a sign of iron deficiency.

Iron deficiency is a multifactorial disease that can stem from not consuming enough iron from food, blood loss, disrupted absorption in the gut or higher iron needs due to exercise, pregnancy or growth.

Causes and Risk Factors

Are you an athlete? Do you engage in strenuous training (long-distance running, CrossFit, cycling, boxing) or are you moving into a high volume phase of strength training?

Your iron requirements are even higher. This is because strenuous exercise, especially high intensity endurance training, causes the body to use more iron for muscle recovery and to create red blood cells for oxygen delivery. You also lose iron through sweat. Female athletes are generally at higher risk of having depleted iron stores than male athletes. This is because women’s overall daily iron requirements (18mg) are more than double that of males (8mg).¹

Are you a generous soul who donates blood regularly? Or do you have really heavy periods?

A surprisingly significant amount of iron is loss during blood loss. On average, women lose about 1.6mg of iron throughout their period with an average blood loss of 40mL. For the 10% of women who have a heavy period, they can lose more than 1.4mg of iron daily throughout their periods.² Therefore, caution should be taken to prioritise iron levels in periods with high blood loss, to ensure stores are replenished.

Thinking about cutting out carbohydrates?

Be mindful that a carbohydrate restricted diet, in particular a low intake of grains, is associated with lower levels of iron.³ You might be surprised to discover that diet low in carbohydrates and red meat can result in inadequate iron intake, even it contains white meat and fish.
In a nation-wide nutrition survey, cereals and wholegrain foods contributed to approximately 40% of overall iron intake in Australians diet. The main sources of iron were bread, breakfast cereals and mixed dishes where wholegrains is a significant component. In comparison, meat and animal products provided less than 20% of Australians’ iron intake.

Highly restricted diets that have limited energy intake or food variety are often low in iron too. Even for short periods of intense dieting, that are common in body-building and gymnastics, extra planning to ensure iron stores are adequate to avoid additional fatigue and complications from micronutrients deficiencies.

Want to learn more about carbohydrates? Check out No-Carb, Low-Carb or High-Carb article that breaks down common carbohydrate myths and explains different types of low-carbohydrate diets.

Following a plant-based diet?

Iron found in plant-based sources is non-haem iron and is harder to absorb than iron found in animal products (haem iron). Therefore, being on vegetarian or vegan diet is a nutritional risk for iron deficiency anaemia.

Although it may be more difficult to achieve iron requirements without animal products, plant-based foods can also be high protein and iron. Being mindful of including iron-rich foods in a diverse and varied diet can help replenish iron stores.

Vegan Iron Sources
Lentils and beans are well-known sources of iron, but did you know dried fruit, nuts and seeds are also important in boosting your iron intake? You can make your own heart-healthy trail mix at home! Munch on it for your afternoon snack or sprinkle it over your oats or breakfast cereal. Make it as savoury or sweet as you desire with a combination of cashews, pepitas, sunflower seeds, sultanas, dried figs and dried apricots.
Want to know a deep, dark secret?:
Dark chocolate also contains iron. Five little squares (50g) of Lindt dark chocolate has 2.5mg of iron. This include the 70% which is not bitter all the way up to 99% which is very bitter! Definitely not a life-changing amount of iron, but it’s one way to end the night on a high note.

Signs and symptoms⁴

  • Early stages of iron depletion: You might not experience any signs or symptoms but your body’s iron stores are running on low. Time for a top up!
  • Iron deficiency: Iron and Haemoglobin levels are lower than normal. The most common symptoms are fatigue and poor concentration.
  • Iron deficiency anaemia: You start struggling to complete normal daily activities because your haemoglobin levels have dropped very low and your body is struggling to get enough oxygen around your body. Common symptoms are dizziness, weakness, cold hands and feet, shortness of breath, and headaches. You may notice brittle nails, pale or dry skin (especially around the mouth), and a sore or swollen tongue. Iron deficiency anaemia has also been linked to lower immunity (increased infection risk), depressive symptoms and severe iron deficiency can also lead to irregular heartbeats.

How much do you need?

Whilst adult males are recommended to have 8mg of iron per day, females above the age of 18 are recommended to consume 18mg of iron per day. That’s more than double! There are currently no specific guidelines on iron requirements for athletes, however, there is some evidence for an additional 1-2mg of iron per day to replace iron losses during exercise.⁵ Other studies have concluded that female athletes engaging in endurance running need up to 70% more iron than current recommendations.⁶ In addition, pregnant women are recommended to have 27mg of iron daily to support additional growth needs.

Curious to see what 18mg of iron in a day looks like?

Breakfast:2 poached eggs, avocado, 2 slices multigrain bread, 1 kiwi fruit4mg
Lunch:100g beef, 1 cup spinach, capsicum, bean sprouts, rice noodles7mg
Snack:1 cup roasted chickpeas3mg
Dinner:Wholemeal pasta, 1 can of tuna, veggies4mg
Total iron:18mg

27mg iron daily in a plant-based diet. Individuals with higher needs or extensive losses e.g. or pregnant women, female athlete, plant-based diet

Breakfast:2 Weetbix(3mg)
soy milk
1 kiwi fruit
3mg
Lunch:200g firm tofu (6mg)
1 cup brown rice (0.7mg)
1 cup broccoli (0.9mg)
1 tablespoon seasame seeds (1mg)
8.6mg
Snack:1 handful of cashew (1.5mg)
3 dried apricots (0.7mg)
2.2mg
Dinner:Vegetarian Spaghetti Bolognese:
1 cup wholemeal pasta (2mg)
2 vege delight sausages (3.5mg)
Tomato and onion sauce
1 cup Spinach (1mg)
6.5mg
Snack:Milo Chia pudding:
3 tsp Milo (3mg)
2 tbsp chia seeds (4mg)
7mg
Total iron:27.3mg

It’s achievable to eat enough iron through your diet on a plant-based diet but a lot of careful planning is required to get in 23mg of iron daily.

5 Easy ways to Up your iron intake

1. Help your body absorb more plant-based iron

Vitamin-C rich foods help your body absorb more non-haem iron from plant-based foods.
Foods high in Vitamin C that would make great additions to your plant-based meals include green leafy vegetables, tomatoes, broccoli, capsicum, cauliflower strawberries, kiwis, , orange, lemon, mandarins and berries.

Red Kiwi Fruit
Red Kiwis are a sweet new variety of kiwis naturally cultivated in New Zealand by the company Zespri. Like the gold kiwis they are derived from, they’re high in soluble and insoluble fibre which is important for gut health. 1 medium kiwi contains 85% of your daily Vitamin C needs, making them a perfect addition to plant-based meals to increase iron absorption.

In search of plant-based meals high in iron?

When choosing vegetarian meals, ensure your protein of choice is paired with vitamin-C rich vegetables or dressing. If you’re limited on choices, add a dqueeze of lemon or lme
One of the most popular plant-based companies is Soulara, who focuses on local Australian produce.

High Iron Meals:

  • Soulara’s supercharged satay bowl is a iron-packed powerhouse with tofu and edamame, with added vitamin c from cabbage and carrots to improve iron absorption
  • Chili sin carne gets iron from the kidney beams and black beans with the added vitamin C from mushroom

Lower in Iron:

  • Mystic black rice pudding has lack rice, coconut cream and coconut sugar as the first three ingredients. You can swap this option out for another high-iron breakfast alternative such as the Ruby sunrise chia pudding. Alternatively, you can add crunch with pumpkin seeds, sweeten with dried fruit or thicken the Mystic black rice pudding with chia seeds.
  • Roje Maiden’s Soba. The main ingredients of this dish is soba noodles, kale, baby corn, capsicum and carrot. Whilst these are all healthy ingredients that are high in vitamin C, they are low in iron. To boost the iron content of this meal, microwave frozen edamame beans, drain and add them.
Prawns High In Iron
Did you know prawns are also high in iron? 100g of prawns has 3mg of highly bioavailable iron. This rocket, avocado and mango salad is also filled with vitamin C to help absorb plant-based iron.

2. Time to spill the tea about your breakfast favourite

Tannic acid in coffee and tea can interfere with iron absorption. Don’t worry you don’t have to give up your coffee and tea. Having them at least an hour before or after meals will prevent them from interfering with all the iron absorption. Swap it out for a small glass of fruit juice to instead of with iron-rich plant foods such as iron-fortified bread and cereals.

Breakfast Cafe
Delicious but vicious when it comes to absorption of non-heme iron in plant foods! Coffee can decrease non-heme iron absorption by up to 40%!⁷
The good news? Coffee and tea doesn’t appear to affect the absorption of heme iron found in animal products⁸
The even better news? Waiting at least one hour after your meal to drink tea or coffee minimally impacts iron absorption.⁹

3. Your preparation and cooking methods matter!

  • Soaking legumes and beans overnight in warm water allows your body to absorb more iron and zinc. The trick is to keep the soaking water and use it to cook your legumes and beans in a pressure cooker, pot or pan.¹⁰,¹¹
  • Using iron-containing pots and pans can increase iron levels. Iron content of food is positively affected by using a new iron skillet, more frequent stirring and longer cooking times. ¹²,¹³
  • Cooking your vegetables can also increase the amount of iron your body can absorb.
Dried Beans & Legumes
Buying dried legumes and beans are an affordable source of iron, protein and fibre. Soak overnight in cold water for 8-12 hours to increase iron availability and make them faster and easier to cook! They’re highly versatile and delicious roasted and used as the main ingredient in salads and curries, blended into hummus or added to Moroccan soups.

4. When it comes to iron-rich meats, beef isn’t your option!

Lean red meat sources include kangaroo, lamb or veal. Aim to have lean-red meat 3-4 times per week if possible, but don’t stop there! Remember to have other iron sources like seafood, chicken, eggs, legumes and beans throughout the week.

Honey Soy Glazed Salmon
Looking for healthy meal ideas? Honey soy glazed salmon on a bed of sauteed onions, mushrooms and broccolini. A wedge of lemon is an easy way to ensure the non-heme iron in this meal is more effectively absorbed.

Looking for the foods rich in iron? Check out this table.

Food (raw weight)Iron
1 beef rump steak (200g)6m
1 cup beef mince5mg
1 Salmon fillet (200g)2mg
1 Chicken breast fillet (200g)1.6mg
2x Large Eggs (100g)1.2mg
1 Tin of tuna (100g)1mg
Tofu (200g)*4mg
Lentils or chickpeas (1 cup)*3mg

*Non-heme iron is less readily absorbed in the human body.

5. Fortified foods are a fast and effortless way to add in iron

Some breakfast cereals are fortified with iron. In particular Uncle Tobu’s plus iron cashews & nutty clusters has 3mg per 40g serving. Bakers Delight Cape Seed loaf also has 2.5mg of iron in just two slices of bread. Adding Milo to milk is a tasty way to add in iron and calcium. If you’re lactose-intolerant or following a vegetarian or vegan diet, Nestle just released a new plant-based milo!

Vegan Milo Smoothie
Fuel your busy mornings with an iron-packed vegan smoothie. Add your plant-based milk of choice, 3tsp of Milo, a small banana and a tablespoon of chia seeds. Don’t worry, the chia seeds are tasteless!

Disclaimer: Unless advised by your medical professional following a blood test, you should not supplement iron. This is because excess iron can be harmful.

References
Bass LJ, McClung JP. Iron Nutrition and the Female Athlete: Countermeasures for the Prevention of Poor Iron Status. Journal of Evidence-Based Complementary & Alternative Medicine. 2011;16(3):195-200. doi:10.1177/2156587211401747
Mary-Jane N. Ofojekwu, FMLSCN, Ogbonnaya U. Nnanna, MLS, Charles E. Okolie, PhD, Lolade A. Odewumi, AMLSCN, Ikechukwu O. U. Isiguzoro, M.Sc, Moses. D. Lugos, M.Sc, Hemoglobin and Serum Iron Concentrations in Menstruating Nulliparous Women in Jos, Nigeria, Laboratory Medicine, Volume 44, Issue 2, May 2013, Pages 121–124, https://doi.org/10.1309/LMM7A0F0QBXEYSSI
Churuangsuk, C, Griffiths, D, Lean, MEJ, Combet, E. Impacts of carbohydrate‐restricted diets on micronutrient intakes and status: A systematic review. Obesity Reviews. 2019; 20: 1132– 1147. https://doi.org/10.1111/obr.12857
Iron Deficiency Anemia. National Heart Lung and Blood Institute. https://www.nhlbi.nih.gov/health-topics/iron-deficiency-anemia
Nielsen, P., Nachtigall, D. Iron Supplementation in Athletes. Sports Med 26, 207–216 (1998). https://doi.org/10.2165/00007256-199826040-00001
Whiting SJ, Barabash WA. Dietary reference intakes for the micronutrients: considerations for physical activity. Appl Physiol Nutr Metab. 2006;31:80–5
Inhibition of food iron absorption by coffee. Morck TA, Lynch SR, Cook JD. Am J Clin Nutr. 1983 Mar; 37(3):416-20
Impact of tea drinking on iron status in the UK: a review. Nelson M, Poulter J. J Hum Nutr Diet. 2004 Feb; 17(1):43-54
Salma F Ahmad Fuzi, Dagmar Koller, Sylvaine Bruggraber, Dora IA Pereira, Jack R Dainty, Sohail Mushtaq, A 1-h time interval between a meal containing iron and consumption of tea attenuates the inhibitory effects on iron absorption: a controlled trial in a cohort of healthy UK women using a stable iron isotope, The American Journal of Clinical Nutrition, Volume 106, Issue 6, December 2017, Pages 1413–1421, https://doi.org/10.3945/ajcn.117.161364
Luo, Y., & Xie, W. (2014). Effect of soaking and sprouting on iron and zinc availability in green and white faba bean (Vicia faba L.). Journal of food science and technology, 51(12), 3970–3976. https://doi.org/10.1007/s13197-012-0921-7
Feitosa, S., Greiner, R., Meinhardt, A. K., Müller, A., Almeida, D. T., & Posten, C. (2018). Effect of Traditional Household Processes on Iron, Zinc and Copper Bioaccessibility in Black Bean (Phaseolus vulgaris L.). Foods (Basel, Switzerland), 7(8), 123. https://doi.org/10.3390/foods7080123
Kulkarni SA, Ekbote VH, Sonawane A, Jeyakumar A, Chiplonkar SA, Khadilkar AV. Beneficial effect of iron pot cooking on iron status. Indian J Pediatr. 2013 Dec;80(12):985-9. doi: 10.1007/s12098-013-1066-z. Epub 2013 Jul 19. PMID: 23868537
Alves, C., Saleh, A., & Alaofè, H. (2019). Iron-containing cookware for the reduction of iron deficiency anemia among children and females of reproductive age in low- and middle-income countries: A systematic review. PloS one, 14(9), e0221094. https://doi.org/10.1371/journal.pone.0221094
Valentina Duong
Valentina Duong
A nutritionist and powerlifter with numerous first place finishes at national and international competitions. Valentina's rediscovering joy, one snack at a time.
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