Calcium is the most abundant mineral in your body, predominantly stored in your bones.
Despite its importance, over 3.5 billion people worldwide are estimated to be deficient. A recent NHANES survey of 16,444 people found that 44% of Americans do not meet the minimum intake for calcium.
In this article, we’ll show you how to get the calcium you need using the tools and charts used by Optimisers in our Micros Masterclass.
- Which Foods Are High in Calcium?
- Calcium Foods Chart
- Highest Calcium Foods (Per Serving)
- Highest Calcium Foods (Per Calorie)
- Highest Calcium Recipes
- What Is Calcium and Why Is It Important?
- Satiety Response to Calcium
- Calcium Availability in the Food System
- Symptoms of Calcium Deficiency
- Risks of Calcium Supplementation
- Interaction with D3 and K2
- Absorption and Bioavailability of Calcium
- Synergistic Nutrients with Calcium
- The Calcium:Magnesium Ratio
- Nutrient Density Starter Pack
- Nutrient Series
Which Foods Are High in Calcium?
Calcium is found readily in plant and animal foods, although it tends to be more bioavailable in animal-sourced foods like cheese.
Dairy foods are the most calcium-dense and bioavailable sources of calcium. These foods also include minimal amounts of vitamin D, which can be helpful in the intestinal absorption of calcium.
While calcium is also available in some plant foods, how much is absorbed is questionable because of phytates, oxalates, and other antinutrients found in some of them. These compounds are known to antagonise the absorption of minerals like calcium.
Calcium Foods Chart
The chart below shows a range of popular foods in terms of calcium (per calorie) vs calcium (per serve). Foods towards the right will provide more calcium per calorie, while the foods towards the top will provide more calcium in the typical serving sizes we eat them.
For more detail, you can dive into the interactive Tableau version of this chart (on your computer), check out the food lists of popular foods below or download longer lists in our Optimising Nutrition Community here.
Highest Calcium Foods (Per Serving)
The foods listed below will provide more calcium in the typical serving sizes we eat them.
- goat cheese
- Swiss cheese
- Edam cheese
- gouda cheese
- cheddar cheese
- parmesan cheese
- mozzarella cheese
- Camembert cheese
- feta cheese
- blue cheese
- milk (whole)
- Greek yogurt (non-fat)
Highest Calcium Foods (Per Calorie)
The food listed below will provide more calcium per calorie; however, because we consume them in very small quantities, it may be harder to get a lot of calcium from them. As noted above, plant-based sources of calcium may be less bioavailable.
- bok choy
- sour pickles
- dill pickles
- mustard greens
- parmesan cheese
- coriander leaf
Highest Calcium Recipes
The chart below shows our 1400+ NutriBooster recipes that we use in the Micros Masterclass plotted in terms of calcium vs protein %. Recipes towards the right will help you boost your calcium with fewer calories.
To dive into the detail, you can open the interactive Tableau version of this chart (on your computer). Click on each recipe to learn more about it and view a picture of the recipe.
What Is Calcium and Why Is It Important?
- Calcium is perhaps most well-known for its importance in the healthy development and maintenance of bones and teeth, blood clotting, and nerve transmission.
- The body requires minerals like calcium for muscle contraction. Magnesium is the mineral that works alongside calcium in this process, allowing for muscle relaxation.
- Calcium is essential for children as they grow and develop. Children who don’t get enough calcium may not grow to their full potential height and may develop other health issues.
- Calcium is a nutrient necessary for the breakdown of histamines.
- We need calcium for cell signalling and stabilising enzymes and other proteins necessary for human metabolism.
- The body needs adequate calcium to detoxify oxalate and heavy metals like lead.
- Calcium helps regulate blood pressure and has been shown in studies to reduce hypertension and preeclampsia in pregnant women.
- Hormone balance is partly regulated by calcium, and calcium can reduce premenstrual syndrome (PMS) and associated symptoms.
- Too little calcium can increase the risk of developing osteoporosis in older people. Osteoporosis is prevalent in older women, meaning the calcium demand in postmenopausal women is greater. Fractures from falls are common in older people with low muscle mass and fragile bones and are often difficult to recover from.
Satiety Response to Calcium
Because calcium is critical for the maintenance of our bones, it appears that we have a specific appetite for it (Tordoff, 2001).
Our satiety analysis shows that foods with more calcium tend to be more satiating. Optimisers who consumed food and meals that contained more calcium per calorie tended to consume 29% fewer calories. As shown in the chart below, our appetite for calcium seems to taper off once we get enough.
The median calcium intake for Optimisers is 1.0 g per 2000 calories, with the 85th percentile of 1.9 g per 2000 calories.
This is higher than the Estimated Average Requirement of 0.84 g per day and the Daily Recommended Intake of 1.2 g per day but less than the upper limit of 2.5 g per day.
Based on this analysis, we have set an Optimal Nutrient Intake for calcium of 1.65 g/2000 calories for men. For more details, see:
Calcium Availability in the Food System
The chart below shows that the calcium content of commonly available foods has decreased significantly since the 1940s with the widespread introduction of chemical fertilisers and modern farming practices (data from the USDA Economic Research Service). Therefore, today, you will need to consume 39% more food to get the same amount of calcium you would have in the 1940s.
Symptoms of Calcium Deficiency
Because calcium is used in so many bodily processes, too little calcium is associated with symptoms including:
- muscle pain,
- brittle fingernails,
- cognitive impairment,
- heart palpitations and atrial fibrillation,
- histamine intolerance and mast cell disorders,
- menstrual cramps,
- numbness and tingling,
- osteoporosis, and
- tooth decay and loss.
Risks of Calcium Supplementation
Studies suggest that a diet rich in calcium protects against heart disease, but supplemental calcium may increase the risk by causing calcium to deposit where we don’t want it, like in your arteries.
- A 2010 BMJ study found that those who used calcium supplements had a 139% greater risk of a heart attack, while an increased intake of calcium from food did not increase the risk.
- A meta-analysis of studies involving more than 12,000 people also found that calcium supplementation increased the risk of heart attack by 31%, stroke by 20% and death from all causes by 9%.
- An analysis of 12,000 men found that more than 1,000 mg of supplemental calcium per day from multivitamins or individual supplements was associated with a 20% increase in the risk of death from cardiovascular disease.
Interaction with D3 and K2
As well as adequate calcium, it’s important to note that you also need sufficient vitamin D to ensure calcium absorption in the intestines and vitamin K2 to ensure calcium is stored in bones and teeth and not your arteries. Ironically, cheese and yogurt are excellent sources of all three nutrients.
Extra calcium intake from supplements, beyond what is required to build your bones and teeth, is excreted in the urine, which increases your risk of calcium kidney stones.
Excess calcium can also build up in your kidneys as your body tries to excrete it. Subsequently, calcium and vitamin K2 from food and vitamin D from adequate sun exposure are critical.
The sudden dump of calcium into the bloodstream from supplements may lead to the calcification of arteries. In contrast, calcium obtained from food is absorbed more slowly and is less likely to build up in places where it doesn’t belong.
Absorption and Bioavailability of Calcium
Plant foods have questionable amounts of absorbable calcium because they contain phytates. For example, phytates in spinach, rhubarb, chard, legumes, grains and cereals can. Therefore, a diet high in refined grains not only provides less calcium, but the phytates ensure that it is not adequately absorbed.
Much like phytates, oxalates are compounds found readily in calcium-containing plant foods. These antinutrients inhibit calcium absorption in the GI tract.
Around 20 – 25% of the calcium in legumes is absorbed. Therefore, soaking legumes can be helpful to remove phytates before eating, to improve calcium absorption. The body absorbs over 30% and 40 – 60% of the calcium in cruciferous vegetables. However, only 5 – 9% of calcium is absorbed from rhubarb and spinach.
Calcium absorption is improved by vitamin D status and resistance training. At the same time, it is made worse by lead exposure, overconsumption of magnesium and potassium, high alcohol consumption, and low hydrochloric acid (stomach acid) levels in the stomach.
It is possible to overdo it and cause harm with the overconsumption of calcium, but this is rare from whole foods and is only a concern with supplements.
Concerns around calcium bioavailability are likely minimal if you consume a broad range of nutrient-dense, calcium-rich foods and get plenty of sunlight. However, you may be disappointed if you drink a lot of green smoothies expecting to absorb a lot of calcium.
Synergistic Nutrients with Calcium
Calcium works synergistically with vitamins A, C, E, D, K2, arginine, boron, carnosine, chromium, copper, lysine, magnesium, methionine, phosphorus, potassium, and selenium. Hence, we recommend getting your calcium from whole food sources packaged with other nutrients rather than relying on isolated supplements.
Getting enough dietary calcium means we need less vitamin D. Excess phosphorus, magnesium, or potassium will increase your calcium requirement. So while you need to ensure you are getting enough of each nutrient, you also need to ensure you are not getting so much that you overwhelm your body’s ability to use other nutrients properly.
The Calcium:Magnesium Ratio
In addition to vitamin D and phosphorus, your body also needs adequate magnesium levels to use calcium properly.
- Magnesium deficiency affects calcium metabolism and alters certain hormones that regulate calcium in the body.
- A high calcium intake may interfere with magnesium levels by reducing intestinal absorption and increasing urinary excretion. Magnesium deficiency is also known to induce calcium deficiency.
- Calcium and magnesium also compete and interfere with one another’s functions if they are out of balance.
- Magnesium may prevent calcium from performing muscular contraction when the ratio of magnesium to calcium is out of balance.
Our analysis suggests that people who consume more calcium than magnesium consume fewer calories. For more details, see Nutrient Balance Ratios: Do They Matter and How Can I Manage Them?
Nutrient Density Starter Pack
To help you increase your intake of all the essential nutrients, including calcium, we’re eager to make the process of Nutritional Optimisation as simple as possible.
When you join our free Optimising Nutrition Community, you’ll get a starter pack that includes:
- Food Lists – optimised for each essential nutrient, goals, preferences and conditions.
- The Healthiest Meal Plan in the World – see what a week of nutrient-dense eating looks like.
- Recipes – check out samples of each of our NutriBosoter recipe books.
- 7-Day Nutrient Clarity Challenge – identify your priority nutrients and the foods and meals that contain them.
- Biotin (B7)
- Vitamin A
- Vitamin E
- Thiamine (B1)
- Riboflavin (B2)
- Niacin (B3)
- Pantothenic acid (B5)
- Vitamin B6
- Folate (B9)
- Vitamin B12
- Vitamin C
- Vitamin D
- Vitamin K1
- Vitamin K2