Main vegan sources of bioavailable calcium

We all know that calcium is the crucial element for our bones health. However, the role of calcium in our body is multifunctional: it makes our heart beat, teeth healthy and strong, our muscle function, our nerves transmit signals, and our hormones create.

Not all calcium that we consumed with food is actually absorbed in our body. Even if foods have very high calcium content, it doesn’t necessarily mean that calcium is bioavailable. Phytic acid and oxalic acid, found naturally in some plants, bind calcium forming water-insoluble substances that inhibit its absorption. Prime examples are: spinach, collard greens, sweet potatoes, rhubarb, and beans.

The best food sources of calcium are of the animal origin – milk and dairy products.

Recent studies suggest that vegans have lower bone densities and are at greater risk of osteoporosis and fractures because most vegan sources of calcium have a much lower bioavailability than dairy. Often, a vegan diet doesn’t match the recommended daily calcium intake. See what else you can add to your daily menu to keep calcium level in your body in a good standing.

What is calcium bioavailability?

Our body cannot produce calcium. The only source of this mineral for us is food. But not all dietary sources of calcium are created equal. Many vegan sources of calcium exist, including seaweeds such as wakame and hijiki; nuts and seeds like almonds, hazelnuts, sesame, and pistachio; blackstrap molasses; beans (especially soy beans); figs; quinoa; okra; rutabaga; broccoli; leaves; and kale. But here the problem of calcium bioavailability arises.

The bioavailability of calcium refers to the fraction of dietary calcium that is potentially can be absorbed and utilized by the body.

For example, spinach has moderate calcium content, but only about 5% of it is bioavailable. In other words, you have to eat tons of spinach to get enough calcium. The same problem may affect the absorption of calcium from amaranth, collard greens, and chicory greens.

Okay, let’s consider what the main vegan sources of bioavailable calcium are.

Main vegan sources of bioavailable calcium

For vegans who don’t consume dairy products, obtaining an adequate intake of bioavailable calcium is essential for maintaining bone health and overall well-being. Here are the main sources of bioavailable calcium for vegans:

Whole wheat bread

The standard serving size of 28g (1 slice) has an average calcium content of 20mg with 70% bioavailability.

Seaweed

Do you think that seaweeds have been consumed by coastal people worldwide for nothing? Due to low levels of oxalic acid and phytates, which bind calcium making it not absorbable in the body, seaweed such as kelp, wakame and hijiki is an excellent source of bioavailable calcium. For instance, in Korea, the soup miyeokguk made out of seaweed named wakame is popularly consumed by women during the pregnancy period and after giving birth. Maybe that is why people in Eastern Asia have such a low rate of osteoporosis. Moreover, seaweed is not only rich in bioavailable calcium, but it is also a pot full of other essential minerals, especially: iodine, iron, and magnesium. Calcium bioavailability is about 60%.

Leafy Greens

Dark leafy greens like kale, collard greens, turnip greens, bok choy, and spinach are rich sources of calcium. Widely considered to be a healthy food, collard greens are excellent sources of calcium. If you ate 2 cups of collard greens, you would be very close to your biological needs for calcium – close but still not enough. One cup of cooked kale, for example, can provide approximately 180mg of calcium. Bioavailability is 45%. These dark leafy greens from the cabbage family is a great vegan source of calcium.

Broccoli

Broccoli is not only a nutritious vegetable but also a good source of calcium. One cup of cooked broccoli contains around 45-60 mg of calcium. Try to include calcium-rich broccoli to your daily menu. Bioavailability is about 50%.

Tofu

Originated in China about 2,000 years ago, tofu is made by coagulating soy milk and then pressing the resulting curds into soft white blocks. It is a widely used component in East Asian and Southeast Asian cuisines. There are many different varieties of tofu that can be used in savory and sweet dishes. The standard serving size of 125g has an average calcium content of 258mg with 31% bioavailability.

Almonds

Almonds are a tasty and convenient snack that also provides calcium. The standard serving size of 125g has an average calcium content of 89mg with 21% bioavailability.

Sesame Seeds

Sesame seeds are rich in calcium and can be sprinkled on salads, stir-fries, or incorporated into recipes. One tablespoon of sesame seeds provides around 88 mg of calcium with 21% bioavailability.

 Prunes and raisins

One cup of prunes contains about 100mg of calcium, or 10% of the recommended daily consumption. Recent studies suggest that eating prunes is linked to higher bone density. However, it’s not only because of calcium, prunes and raisins also contain high amounts of polyphenols, which are important for bone health.

It’s important for vegans to consume a variety of these calcium-rich foods regularly to ensure they meet their daily calcium needs. Additionally, combining sources of calcium with foods high in vitamin D and magnesium can enhance calcium absorption and contribute to overall bone health.