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Is Calcium Sabotaging Your Iron Levels? Discover the Truth

Is Calcium Sabotaging Your Iron Levels? Discover the Truth

Susie cutting fresh vegetables

Perimenopause and menopause can present many challenges, as I’m sure you know already…and one aspect of our health that can be overlooked is how our nutrition affects our mood and energy.

Two essential minerals — iron and calcium — help our bodies function well (and are especially critical at this time of life) plus they can significantly affect how we feel. In this post, I’ll dive into how these nutrients impact mood and why balancing them during peri and menopause is essential for your experience of this time of life.

The Iron-Calcium Connection

Iron and calcium are vital, but they don’t always play nicely together when it comes to absorption.

When consumed in large amounts at the same meal, calcium can block your body from absorbing iron, especially non-heme iron from plant-based sources like spinach and lentils. This doesn’t mean you should avoid calcium-rich foods—it just means spacing out your calcium and iron intake, especially if you have low iron or heavy periods.

For example, if you have a dairy-rich breakfast, opt for an iron-rich lunch. This gives your body the best chance to absorb both nutrients effectively.

The Science Behind Iron and Calcium Absorption (For the Science Nerds)

Why don’t iron and calcium always get along regarding absorption? The key issue lies in how both minerals are absorbed in the small intestine. Iron, especially non-heme iron from plant sources, and calcium compete for the same absorption pathways in the body. Calcium can inhibit iron transport across the intestinal cells by blocking the divalent metal transporter 1 (DMT1), which brings non-heme iron into the bloodstream. This is especially true when large doses of calcium are consumed simultaneously as iron-rich foods.

The interaction is most significant with non-heme iron, which has a lower bioavailability than heme iron (found in animal products). Heme iron uses a different absorption pathway, so calcium has less of an effect on it. However, the absorption
of non-heme iron can drop significantly—up to 50%—when consumed with high calcium levels.

Additionally, calcium in the digestive tract alters the pH balance, making the environment less acidic. Iron is more soluble and better absorbed in acidic conditions, which means calcium’s neutralizing effect further reduces the iron absorption process.

This doesn’t mean calcium should be avoided, though. It just means timing matters. Separating calcium and iron-rich meals by a few hours helps each mineral absorb without interference. For example, having calcium rich foods for breakfast and an iron-rich lunch can help balance out their absorption.

Iron and Mood

Iron plays a huge role in our energy levels. It’s responsible for helping red blood cells carry oxygen throughout the body. When you’re low on iron, you might notice fatigue, weakness, or a foggy brain, making it hard to focus on tasks. But beyond energy,
iron is also crucial for producing neurotransmitters like dopamine and serotonin—two chemicals that regulate mood. A shortage of iron can throw off your balance, leading to symptoms like irritability, anxiety, or even depression. This is why ensuring you get enough iron in peri and menopause is especially important as mood changes and fatigue are common with the changes in our hormones so when you layer nutrient deficiencies on top of this – it’s a problem. But one that is easily solved – yay!

Who’s at Risk for Iron Deficiency?

There’s almost an epidemic of iron deficiency at the moment! Have you noticed that amongst friends or experienced this too? So many of the women I see in clinic have had or are thinking about iron infusions and this can be for multiple reasons.

Of course, heavy periods are a factor and can be common in perimenopausal women. This can be from fibroids, adenomyosis, endometriosis and hormonal changes. All of these can be addressed or at least improved with personalised nutrition and herbal medicine.

If you follow a predominantly plant-based diet, then you’ll be receiving non-heme iron in your food so you can improve absorption of this by increasing your intake of iron- rich foods like lentils, tofu, eggs, nuts and seeds, leafy greens, dried apricots, etc. and eat them with vitamin C-rich foods (like oranges, strawberries, capsicum, guava, blackcurrants, etc.) to boost absorption.

Calcium and Bone Health

Calcium is best known for its role in maintaining strong bones and teeth. While that’s crucial throughout your life span, perimenopause and menopause can be particularly challenging for bone health because the drop in oestrogen and progesterone contributes to a loss of bone density and on average, women lose 10% of their bone density in the first 5 years post-menopause. And this is completely asymptomatic until you have a fracture from a light injury.

Calcium and Mental Health

But calcium isn’t just about bones—there’s growing evidence that calcium also plays a role in mental health. Calcium is involved in the nervous system, helping nerve cells communicate. Low calcium levels have been linked to mood changes,
irritability, and, in extreme cases, depression. Ensuring you get enough calcium through diet or supplements can help keep your bones and mood in good shape during perimenopause and menopause.

 

5 Steps to Improve Your Iron and Calcium Levels Right Now

#1. Time your meals smartly.

Eat calcium and iron-rich foods at different times. For instance, have a calcium-rich breakfast like yoghurt or nuts and seeds sauteed in balsamic vinegar with leafy greens, then an iron-rich lunch with eggs, legumes and leafy greens.

#2. Add vitamin C.

Pair sources of iron with vitamin C-rich foods to improve absorption. Try adding capsicum, tomatoes, or citrus to your iron-rich meals.

#3. Include Vitamin D foods:

Foods like fatty fish (salmon, sardines), eggs or mushrooms exposed to UV light to maintain healthy vitamin D levels. Plus spend time in the sun daily whenever possible.

#4. Incorporate weight-bearing exercises.

Keeping bones strong isn’t just about calcium—exercise plays a role, too. Activities like walking, jogging, or strength training can help maintain bone density, and it’s essential to keep your body moving in peri and menopause.

#5 Avoid Iron Blockers

Dark coloured beverages like coffee, tea, some herbal teas, cola and red wine contain tannins, which block your iron receptors when you have these with meals. If you struggle to keep your iron levels up, space out your intake of these drinks at least 2 hours away from your iron-rich meals.

The Upshot

Perimenopause and Menopause can challenge your physical and mental well-being but paying attention to your nutrition, including your iron and calcium intake can help keep you energised and in a good mood. Balancing these two essential nutrients and making a few strategic changes to your diet can support your body and mind and may reduce the need for  supplementation.

 

Sources and Further Reading:

Zijp IM, Korver O, Tijburg LB. Effect of tea and other dietary factors on iron absorption. Crit Rev Food Sci Nutr. 2000 Sep;40(5):371-98. doi:
10.1080/10408690091189194. PMID: 11029010.

Ito T, Jensen RT. Association of long-term proton pump inhibitor therapy with bone fractures and effects on absorption of calcium, vitamin B12, iron, and magnesium. Curr Gastroenterol Rep. 2010 Dec;12(6):448-57. doi: 10.1007/s11894-010-0141-0.
PMID: 20882439; PMCID: PMC2974811.

Lynch SR, Cook JD. Interaction of vitamin C and iron. Ann N Y Acad Sci. 1980;355:32-44. doi: 10.1111/j.1749-6632.1980.tb21325.x. PMID: 6940487.

Cook JD, Dassenko SA, Whittaker P. Calcium supplementation: effect on iron absorption. Am J Clin Nutr. 1991 Jan;53(1):106-11. doi: 10.1093/ajcn/53.1.106. PMID: 1984334.

Hurrell R, Egli I. Iron bioavailability and dietary reference values. Am J Clin Nutr. 2010 May;91(5):1461S-1467S. doi: 10.3945/ajcn.2010.28674F. Epub 2010 Mar 3. PMID: 20200263.

Cegarra L, Aguirre P, Nuñez MT, Gerdtzen ZP, Salgado JC. Calcium is a noncompetitive inhibitor of DMT1 on the intestinal iron absorption process: empirical evidence and mathematical modeling analysis. Am J Physiol Cell Physiol. 2022 Dec 1;323(6):C1791-C1806. doi: 10.1152/ajpcell.00411.2022. Epub 2022 Nov 7. PMID: 36342159.

Susie Garden | Peri/Menopause Naturopath & Weight Loss Nutritionist

Are you a woman feeling stressed, flat and experiencing the challenges of peri/menopause?
It’s time to reclaim your youthful energy, radiance and self-assurance (and your ideal weight).
I’m here to help with my proven method.

Book your complimentary Introduction Call here, and let’s see how I might help you.