Ζωικές και φυτικές πηγές σιδήρου. Myths & Maths

Lets try to be serious now, Calcium is serious stuff people!!

(Don’t get bored please)

Calcium is an element of great importance for a healthy homeostasis inside a human body. Three organs regulate Calcium homeostasis. Bones, kidneys & parathyroid glands. Important regulator hormone is Vitamin D. Any dysfunction in any of these organs cause hypercalcemia or hypocalcemia.

But let’s get back to the sources. Where do we get Calcium from? Food obviously. It gets absorbed from the intestine & then transferred into our bones where 99% is stored and the rest 1 % circulates in blood & some fracture gets excreted by feces & urine. And is that 1 % that is strictly regulated by complicated hormonal & metabolic pathways that deserve our full admiration!

But calcium deposition into bones happens during growing. Miller, in a review of this area, concluded that lactose enhances Ca absorption in human infants while, at levels normally present in milk, lactose does not have a significant effect on Ca absorption by healthy adults (Miller, 1989). Meaning perhaps that adults are not supposed to drink milk in the first place? Just saying!

What modern societies are afraid of is Bone mass loss. Bone mass in later life depends on Peak Bone Mass achieved until the age of 20-35 years. So optimal calcium intake till our 35 years of age is the key to reduce chances of bone fractures and osteoporosis in later life. Then we slowly begin to loose bone mass inevitably. It’s called aging. Now that is something humans can’t deal with. Especially scientists! So they tell us to take supplements & drink milk & dairy to decrease slightly the inevitable natural course of bone loss.

So you convinced yourself to stop eating dairy, or you are lactose intolerant, or you don’t like cheese or yogurt. Well, don’t be alarmed because,

plant sources of Calcium are not only real,

they are


to animal sources!


  1. Plants contain large amounts of Calcium yet what about bioavailability? Basically think of it as absorbability: A marker that ensures that Calcium is effectively absorbed and utilized by our body. High dietary intake of calcium, especially plant calcium, reduces the risk of osteoporosis and increased bone mineral density in postmenopausal women. What about that revelation? Exceptions are seeds & some greens like spinach, because of high amount of oxalates, Calcium doesnt get absorbed effectively.
  2. How rapidly calcium is lost depends, in part, on the kind and amount of protein you eat, as well as other diet and lifestyle choices. Diets that are high in protein cause more calcium to be lost through the urine. Protein from animal products is much more likely to cause calcium loss than protein from plant foods. This may be one reason that vegetarians tend to have stronger bones than meat-eaters. Meat, is very acidic, and the body reacts to re-balance its pH by taking alkaline calcium out of the bones to neutralize the acid. For every 1 gram animal protein in your diet, you can expect 1 milligram calcium to be lost or eliminated in your urine.
  3. Diets high in sodium, caffeine, smoking, all contribute in higher amount of calcium loss.
  4. Magnesium is substancial for Calcium absorption but dairy does not contain much.
  5. Lastly, the efficiency of absorption decreases as calcium intake increases. Weird right?

Plantbased sources of calcium

Green leafy vegetables: spring greens, kale, broccoli, parsley, turnips.

Fortified foods such as soya milk

White flour, whole wheat flour, oats,


Oranges, Figs and black molasses

See Calcium content in Foods List Here:

Nutrient List Index

Its a Database of all nutrient content in Foods by the USA department of agriculture. Simply fill in the nutrients you want to search and the food groups if you want to narrow down the search! Amazing right?!?

Table 1. Foods ranked according to absorbability of calcium. This table lists the key facts about foods in relation to their calcium absorbability divided into four categories
Absorbability of calcium Food
Excellent >50% Kale, broccoli, turnip greens, brussels sprouts, rutabaga, mustard greens, bok choy, cauliflower, watercress
Good ∼30% Milk, dairy products, yogurt, soy milk, calcium-set soy tofu, soy isolates
Fair ∼20% Almonds, sesame seeds, pinto beans, sweet potatoes, nuts
Poor ∼5% Spinach, rhubarb, collard greens

So, Not all greens are an excellent Calcium source. Check out spinach, with a less tham 5% absorption of its Calcium content due to inhibition by its high oxalates content.

Now lets say you want to start checking out plant based milks.

Here you go:

Nutrition comparison per 1 cup

Carbohydrates (total) Sugars Fat (total) Protein    Calcium
Cow’s milk (whole) 12 g 12 g 8 g 8 g               305 mg
Cow’s milk (1%) 12 g 12 g 2 g 8 g
Cow’s milk (skim)

Goat’s milk

12 g

11 g

12 g

11 g

0 g

6.5 g

8 g

10.9 g          327 mg

Almond milk (fortified) 1 g 0 g 3 g 2 g               240 mg
Soy milk (fortified) 4 g 1 g 4 g 7 g              250 mg
Rice milk (fortified) 22 g 10 g 2 g 0 g               283 mg
Coconut milk beverage (unsweetened) 2 g 0 g 5 g 0 g               249 mg

In red you see my choice for my 2, 5 year old toddler. And she loves it! All the protein with minimum sugars. Oh, and soy is not all genetically modified. Well, almost 85 % of it. But if your soy drink says GMO free, believe it.

So lets write down an example of a

1000mg calcium intake of an adult on a dairy free, plantbased diet!

1 cup of orange juice =300 mg (50mg / fruit)

chickpeas 1 cup =217 mg

or broccoli 1 cup = 250 mg or collard greens 1oo gr = 267 mg

soy milk  150 ml and oats 100 gr = 235 mg

Easy right?

So, to wrap it up, plants provide good source of calcium along with so much more nutrients! They alkalize our bodies pH which is substantial for a healthy, disease free body. Alcaline foods help maintain a pure healthy momentum in our body! On the contrary, highly acidic food such as meat & dairy provide good source of calcium but the bioavailability is lower because of acidic pH & low magnesium of dairy. For children, plant based milk represents an equally good source of Calcium compared to animal milk, plus, plant milk provides better absorption and many other important nutrients.

Is Animal’s Milk safe for humans?

Animal milk is not only inferior to plant milk as far as nutrients are concerned, it’s also can be dangerous. Modern techniques require high doses of antibiotics in order to maintain a low bacteria content. This is very detrimental for our health as antibiotic resistance is an issue of critical importance since humanity’s existence and longer life expectancy is primary attributed to the usage of antibiotics to combat infection. It has been demonstrated from multiple research that consumption of dairy increases the risk of prostate cancer, ovarian & maybe breast cancer. That is attributed mainly to the high hormone level (estrogens) contained in milk products,


Not to mention, it is not ours to take. Interfering and exploiting breast feeding mammals is unethical based on a common rationale. Humans are not supposed to or even need any dairy intake beyond the first years of life. Common modern practices are misguiding and manipulating people that wish to sustain a so called better health while at the same time they are feeding  us a lie.

About my research sources, I have all the bibliography down here for you!


Milk stimulates growth of prostate cancer cells in culture. Tate PL, et al. Nutr Cancer. 2011 Nov;63(8):1361-6. doi: 10.1080/01635581.2011.609306. Epub 2011 Nov 1.





Calcium from plant sources is beneficial to lowering the risk of osteoporosis in postmenopausal Korean women. Park HM1, Heo J, Park Y. Nutr Res. 2011 Jan;31(1):27-32. doi: 10.1016/j.nutres.2010.12.005.

Cashman, K. (2002). Calcium intake, calcium bioavailability and bone health. British Journal of Nutrition, 87(S2), S169-S177. doi:10.1079/BJN/2002534


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