In recent years, many advertisers have heavily promoted the consumption of dairy products for calcium supplementation, leading people to believe that consuming more animal-based foods like milk is the only effective way to supplement calcium. However, some of the latest scientific research has found that consuming milk does not mean the body is free from calcium deficiency. Regular consumption of green vegetables and fruits can also supplement calcium and strengthen bones.
Not long ago, the Physicians Committee for Responsible Medicine, a non-profit organization in the United States, released a report stating that the likelihood of fractures among milk drinkers is no lower than among those with a primarily vegetarian diet. Fractures are a dangerous consequence caused by calcium deficiency and osteoporosis. A vegetarian-promoting organization in the U.S. has challenged modern medicine and the dairy industry, claiming that vegetables are more beneficial than milk in preventing osteoporosis. As early as 1997, Diana Feskanich and colleagues at the Harvard School of Public Health, based on data from the "Nurses' Health Study," which involved tens of thousands of nurses, showed that people who consumed more milk throughout their lives were more prone to fractures in old age compared to those who consumed almost no dairy products. While past medical reports indicated that although vegetables contain a certain amount of calcium, its absorption by the body is reduced due to the influence of phytic acid and oxalic acid. New research, however, suggests that the absorption rate of calcium from some vegetables, such as mustard greens and bok choy, is much higher than from milk. Therefore, a vegetarian diet does not necessarily lead to calcium deficiency. Scientists have determined that an 8-ounce glass of orange juice contains 350 milligrams of calcium, of which 130 milligrams can be absorbed by the body. An 8-ounce glass of milk contains 291 milligrams of calcium, of which only 93 milligrams can be absorbed. Cooked mustard greens, equivalent in weight to 100 grams of milk, contain 128 milligrams of calcium, with 74 milligrams being absorbable. Every 100 grams of soybeans contain 170 milligrams of calcium, and every 100 grams of celery contain 160 milligrams of calcium, with more than half of the calcium in each being absorbable and usable by the body.
Although the calcium content in 100 grams of milk is as high as nearly 300 milligrams, why can't the calcium in it be absorbed and utilized by the body to a greater extent? Scientists believe this is because the phosphorus content in milk is quite high, and an improper calcium-to-phosphorus ratio affects the body's absorption of calcium. On the other hand, although dairy products are high in calcium, they are also high in fat. The high protein content in milk can also hinder the body's proper absorption of calcium. Therefore, vegetables and fruits are the best sources of calcium for the body.