On a plant-based diet calcium is a critical nutrient to watch out for!
The issues we see in raw vegans living in cold climates are often related to calcium deficiency: Weak teeth, dry and thin skin, and low bone density. But don’t give up just yet: We can get enough calcium from raw plants if we know the sources. And while it’s harder to find calcium-rich foods on a plant-based diet, plant calcium is more bioavailable than calcium found in milk!
For quick readers:
- An adult human needs around 1000 mg of calcium per day. The calcium content in raw plant foods ranges from only 5 milligrams to over 200 mg per 100 grams of food. Most foods that we eat in bulk contain only 10-20 mg per 100 grams. Therefore, we need to know which foods are calcium-rich or what functional foods and natural supplements to take in order to meet our daily needs.
- Fresh figs, açai berry, jackfruit, most citruses, almonds, Brazil nuts, and pistachios are raw vegan foods that are high in calcium.
- Calcium intake can be challenging based on fruits, nuts, and greens alone, depending on your food availability. Thus, it might be valuable to integrate a functional food like calcium-rich red algae algae and green leaf powders like moringa. Home-made almond milk, fresh celery juice, citrus juices and dried figs are another way to get more calcium.
- To boost your calcium absorption, make sure you are getting enough vitamin D, iron, and magnesium. Further, avoid eating an excess of antinutrient-rich foods and coffee, which interfere with calcium absorption.
In this article, you find an overview and lists of the calcium content found in different types of fruits and vegan raw foods, the foods you can integrate into your diet to get enough calcium, and what other factors enhance or decrease calcium absorption:
Calcium content of fruits
Fruits, greens, and nuts highly vary in their calcium content! Therefore we need to know what we are doing regarding our intake on a raw vegan diet.
| Fruit | Calcium (mg) |
|---|---|
| Oranges | 40 |
| Tangerins | 40 |
| Jackfruit | 37 |
| Figs (fresh) | 35 |
| Açai berry | 35 |
| Mandarin | 33 |
| Grapefruit | 22 |
| Papaya | 20 |
| Guava | 18 |
| Cucumber | 16 |
| Cherries | 16 |
| Strawberries | 16 |
| Dragonfruit | 16 |
| Zucchini | 16 |
| Cherimoya | 15 |
| Mangosteen | 15 |
| Pineapple | 13 |
| Apricots | 13 |
| Mango | 11 |
| Lychee | 10 |
| Avocado | 10 |
| Blueberries | 9 |
| Pears | 9 |
| Tomatoes | 6 |
| Durian | 6 |
| Plums | 6 |
| Apples | 6 |
| Bananas | 5 |
| Average Fruit | ca. 16-17 mg |
Dried figs are a valuable source of calcium if you struggle to meet your daily needs: 100 grams of dried figs contain around 160 mg of calcium! Interestingly, figs are also a staple food of chimpanzees! A bit of a disappointment is banana in this list: The fruit that is famous as a good source of minerals like potassium and magnesium is very low in calcium. Chimps also eat a substantial amount of leafy greens.
Calcium content of greens and nuts
In this overview of calcium in greens and nuts I excluded the vegetables with high oxalic acid content in the table (like spinach and rhubarb), as the anti-nutrient prevents absorption of calcium. Therefore, they are not effective sources of calcium for our body.
Why do they contain those antinutrients? Leaves and stems, as plant parts, protect themselves from being eaten by producing unfriendly chemicals. Fruits, on the other hand, do not. This is why the nutrients in fruits are highly bioavailable (read more here about the fruit-frugivore dynamics in nutrition).
| Food | Approx. Calcium content in mg |
|---|---|
| Red algae Phymatolithon calcareum | 200-400 / capsule |
| Moringa powder | 300-500 / 5 tbsp |
| Almonds | 260 |
| Brazil nuts | 160 |
| Brokkoli sprouts | 107 |
| Pistachio | 105 |
| Walnuts | 98 |
| Macadamia nuts | 85 |
| Sellerie | 80 |
| Pecan nuts | 73 |
| Seaweed Irishmoss | 72 |
| Pak choi | 40-100 |
| Sesame seeds | 40 / tbsp |
| Cashew | 37 |
| Lettuce | 33 |
| Chia seeds | 30 / tbsp |
| Turnip | 30 |
| Coconut | 16 |
Nutrient content in wild fruits: Calcium has dropped!
We, humans, do not live in our natural habitat. Most of us do not have access to wild, ripe tropical fruits like our closest relatives, the chimpanzees. Why does this matter? Because wild fruits contain more calcium than modern cultivated ones, which makes it challenging to get all we need. We might need to adapt to our new and sad condition of having a “poor and dirty” food supply:
“A sharp decline rate was observed in calcium, with 57.4 percent in lemons, 58.8 percent in pineapples, and 65 percent in tangerines during 1975 to 2001. “
Bhardwaj et al. (2022)
So who knows, how much calcium is really in the orange we buy at the supermarket!
Wild fruits have a different nutritional profile than cultivated fruits and temperate fruits (which are all cultivated and hybridized). In general, wild fruits contain more minerals than the modern fruits in our food supply (which have decreased in minerals, including calcium significantly over the decades) and a different carb composition.
“Humans clearly come from an evolutionary past in which hexose (fructose) – rather than sucrose-dominated fruits were consumed, and human digestive physiology should, therefore, be best adapted to a carbohydrate substrate similar to that of wild fruits. But, in addition, wild fruits differ in other respects from their cultivated counterparts. These include a high content of roughage – woody seeds, fibrous strands – as well as higher average protein levels, higher levels of many micronutrients … and , at times, considerable pectin.”
Kathrine Milton; 1999
Calcium on a raw vegan diet: How to get enough
Choosing the right raw foods can provide a substantial amount of our daily nutritional needs for calcium. The recommended daily amount for adults is around 1000 mg of calcium per day:
- Fruits: Fruits contain only around 17 mg/100 grams of calcium on average. Fruits hold a very high water content, which is why the calcium content appears to be relatively low compared to “denser” foods. But let’s see it like that: Fresh fruits provide nutrients and water in one. Further, unlike nuts and greens, fruits do not contain anti-nutrients like phytic acid or oxalates that interfere with mineral absorption. Some fruits are calcium-rich and can deliver up to 40 milligrams of calcium per 100 grams, and even more in dried fruits: Fresh figs, açai berry, jackfruit, and most citruses are high in calcium and deliver around 350 mg per kg of fruit. Dried figs contain around 160 mg per 100 grams. Nonetheless, on average 1 kg of fruit only contains 170 mg of calcium!
- Greens and nuts: While we can eat much more fruits than nuts or greens in volume, nuts, and greens, as nutrient-dense foods, are also richer in calcium than fruits! Almonds, Brazil nuts, and Pistachios contain around 100-250 mg per 100 g. The red algae Phymatolithon calcareum is a natural supplement that can easily meet our needs!
All food categories, fruits, nuts and greens in combination, are important calcium sources in the natural human diet! Thus, to boost our intake, we can integrate fruits high in calcium, like figs or citruses, as well as add tender leafy greens, nuts and calcium-rich seaweed, and green leaf powder like moringa. This is in line with the natural human diet: As a frugivorous species, we would eat large amounts of tropical fruits, greens, and nuts in a natural setting!
Calcium absorption: The sun and fruits!
For calcium absorption, vitamin D (sun) and vitamin C (fruits) are essential. Once more this shows that we are a frugivorous species, and that we are a tropical species!
When we adopt a raw vegan diet, we always need to keep in mind that we are a tropical species and need the conditions of the climate and food sources to get everything we need. And every nutrient connects with other nutrients. This is why there often is a cascade of deficiency when we miss out on one! And often missing out on enough sunshine is a critical point when you live in cold climates! Our ancestors ate fatty fish, or fish oil for vitamin D to survive when they didn’t get enough sun exposure. They ate dairy to get a calcium-dense food. They didn’t have the possibility to do it the plant way like we do today! Today we can imitate our tropical environment with supplements and imported foods.
Not getting enough sun or a vitamin D3 supplement on a raw vegan diet can lead to low iron and calcium absorption. Additionally, tropical fruits and tender greens have fewer anti-nutrients that interfere with calcium absorption compared to other plant foods (typically found in a modern plant-based diet). And fruits contains vitamin C which boosts calcium absorption.
Magnesium and Vitamin K2 (which is produced by the microbiome under healthy conditions) should also be considered alongside vitamin D to aid calcium absorption and its transportation. Magnesium is depleted in our food supply, and we need more due to a higher metabolic demand due to enhanced detoxification and vitamin D supplementation. While getting it through the skin might not cut it, taking a dead sea salt bath frequently can help with getting magnesium naturally.
Conclusions
Depending on your food availability, calcium intake can be challenging based on fruits, nuts, and greens alone. Thus, it might be valuable to integrate a functional food like calcium-rich algae and green powders. Homemade almond milk, fresh celery juice, and citrus juices are another way to get more calcium.
To boost your calcium absorption, make sure you are getting enough vitamin D, iron, and magnesium. Further, avoid eating an excess of antinutrient-rich foods and coffee, which interfere with calcium absorption.
Do you need an overview of the WHY and HOW of following a
Frugivore Diet?
References
- Dani Sarusi, 10 things chimpanzees eat. Jane Goodall (2022) (available at https://janegoodall.ca/our-stories/10-things-chimpanzees-eat/).
- Bhardwaj, R.L. et al. (2024) ‘An alarming decline in the nutritional quality of foods: The biggest challenge for Future Generations’ Health’, Foods, 13(6), p. 877. doi:10.3390/foods13060877.
- K. Milton, Nutritional characteristics of wild primate foods: Do the diets of our closest living relatives have lessons for us? Nutrition. 15, 488–498 (1999), doi:10.1016/s0899-9007(99)00078-7
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