Many people know they might be calcium deficient, and many also regularly take calcium supplements. However, how to promote calcium absorption in one's diet is not something everyone knows. A small misstep can lead to falling into common misconceptions, choosing the wrong foods, and ultimately hindering calcium absorption. Dr. Fan Zhihong, a council member of the Chinese Nutrition Society, points out common calcium supplementation myths. Which ones apply to you?
1. Thinking eating beef is good for bones
Many people believe that Westerners have strong bones because they love beef. In fact, many people who eat a lot of beef are those who are severely calcium deficient. This is because beef itself is extremely low in calcium, and this is true for all meats. At the same time, meat contains a large amount of "acid-forming elements," primarily phosphorus, sulfur, and chlorine. These make the blood more acidic, and the body has to use calcium ions from food and bones to neutralize these elements, thereby increasing calcium loss and reducing calcium absorption. Therefore, middle-aged and elderly people who are calcium deficient should appropriately control their intake of meat, whether it's red meat or white meat.
2. Thinking eating vegetables has nothing to do with bone health
While many people love animal products, they often neglect to supplement with vegetables. They believe vegetables only contain dietary fiber and vitamins and are unrelated to bone health. In reality, vegetables not only contain large amounts of potassium and magnesium, which help maintain acid-base balance and reduce calcium loss, but they also contain a fair amount of calcium themselves. Leafy green vegetables are generally moderate sources of calcium, such as bok choy, napa cabbage, kale, and celery, and they should not be overlooked as calcium-rich vegetables. Recent research has confirmed that vitamin K in leafy greens is essential for the formation of osteocalcin, which is necessary for depositing calcium into bones.
3. Thinking spinach is useless for calcium supplementation
Many people know that spinach should not be eaten with tofu because it contains a lot of oxalic acid, which will bind with calcium to form an insoluble precipitate. However, these people overlook the other side of the issue: spinach also contains many factors that promote calcium absorption, including abundant potassium and magnesium, as well as vitamin K. Spinach is a recognized treasure trove of vitamin K, with its content ranking first among various fresh and raw foods. Vitamin K is not afraid of heat and, like carotene, requires oil for absorption. Therefore, when eating cold spinach, be sure to add some sesame oil.
4. Thinking eating fruit as a meal replacement is good for bone health
Many women who diet believe they can get enough protein and vitamins just by eating fruit and often replace a meal with fruit. In reality, while fruit is beneficial for acid-base balance, it is not a good source of calcium and is severely lacking in protein. Bone formation requires a large amount of calcium and also collagen as a framework for calcium deposition. If meals are replaced with fruit, both protein and calcium intake will be severely insufficient, which will only promote osteoporosis.
5. Thinking drinking beverages has nothing to do with calcium supplementation
To improve taste, most beverages contain phosphates, which severely hinder calcium absorption and promote calcium loss. Cola is the most harmful among them because it contains phosphoric acid. If you soak human teeth and bones in cola, they will slowly dissolve! The refined sugar in it is also not good for calcium absorption. Therefore, anyone who needs to supplement calcium must strictly control their intake of sweet beverages. Tea is rich in potassium ions, has a low phosphorus content, and also contains fluorine, which promotes strong bones and teeth. Therefore, drinking tea is beneficial and harmless for bone health. But be careful with so-called "tea beverages"; their color may be from caramel coloring and do not provide the benefits of tea.
6. Believing that drinking bone soup will prevent calcium deficiency
The calcium in bones will not easily dissolve out. Experiments have shown that after being steamed in a pressure cooker for two hours, the fat from the marrow floats to the surface, but the calcium content in the soup is still negligible. There is only one way to use bone soup for calcium supplementation: add half a bowl of vinegar and simmer it slowly for another one to two hours. Vinegar can effectively help dissolve bone calcium. It should be noted: do not use a pressure cooker for this; it's best to use a clay pot to avoid dissolving too much aluminum into the bone soup.
7. Believing that drinking milk is not helpful for calcium supplementation
Although some people claim everywhere that milk contains a lot of protein, which will make the body more acidic and promote calcium loss, this statement is incorrect. In fact, milk's protein content is only 3%, while its water content is as high as 87%. Every 250 grams of milk contains over 250 milligrams of calcium, as well as abundant potassium and magnesium, and also contains vitamin D, lactose, and essential amino acids that promote calcium absorption. Unlike meat, milk is not an acid-forming food but a weakly alkaline one. Therefore, milk does not make body fluids acidic and will not promote calcium loss. Overall, milk is still the best food for calcium supplementation.
8. Believing soy milk is a high-calcium food
Nutritionists often advise that people who cannot drink milk can drink soy milk as an alternative. Indeed, in many ways, soy milk is an excellent food, but in terms of calcium content, it is far inferior to milk—the difference is not just one or two times. This is because although the calcium content of soybeans is not too low, after grinding 10 cups of water with them to make soy milk, the content is greatly diluted. Drinking a cup of soy milk is equivalent to eating only a few dozen soybeans, so the calcium content is very low. The real benefit of soy milk for bones is that it can provide phytoestrogens, which reduce calcium loss in menopausal women.
9. Believing seaweed can supplement calcium
Many media articles tell you that seaweed contains a lot of calcium, but this is only true for dried seaweed. But who can eat a large amount of dried seaweed? Once it absorbs water, the calcium content is no longer that high. Moreover, soluble dietary fibers in seaweed, such as alginic acid, can hinder calcium absorption because they can form strong complexes with calcium, escorting it "straight through the gut." But seaweed is not entirely useless; it is a typical alkaline food, and regular consumption can help reduce calcium loss in the body.
10. Using silken tofu to supplement calcium
Many people know that tofu is the best calcium-rich food among plant-based foods. Soybeans themselves contain a fair amount of calcium, and a calcium-containing coagulant is added when making tofu, so people who don't drink milk consciously eat more of it. However, silken tofu is not a good source of calcium because it does not use a calcium-containing coagulant; instead, it uses glucono-delta-lactone as a coagulant. At the same time, silken tofu contains too much water, so its protein and calcium content are very low. Besides silken tofu, "Japanese tofu" should also not be used for calcium supplementation.