Nutrition Action
Is calcium deficiency just a problem for the elderly? Of course not. Throughout life, people need to prevent calcium deficiency. This is especially true during special periods such as infants, adolescents, pregnancy and lactation. But if these things are not known, calcium will be supplemented in vain, and the effect of calcium supplementation may be half the work.
The calcium content of soy milk is only about one-tenth of that of milk
Stick bone broth and the like do not supplement calcium
So, what foods to eat to supplement calcium? Dairy products, soy products and green leafy vegetables are the main force of calcium supplementation in the diet of Chinese residents.
Dairy products: Milk, yogurt, cheese and other dairy foods are all good foods for calcium supplementation. They have high calcium utilization, are easy to eat, and contain vitamin D, lactose, essential amino acids, casein phosphopeptides and many other factors that promote calcium utilization.
Soy products: brine tofu, gypsum tofu and dried tofu, tofu shredded and other soy products are good sources of calcium and magnesium. However, in terms of calcium supplementation, soy milk is completely inferior to milk, and the calcium content of soy milk is only about one-tenth of milk. In addition, lactone tofu, sour pulp tofu has a large moisture content, which does not add gypsum or brine, calcium and magnesium content is relatively low.
Milky white soups such as stick bone soup and pork foot soup cannot supplement calcium. Experiments have proved that after two hours of steaming in the pressure cooker, the fat in the bone marrow has surfaced, but the calcium in the soup is still minimal. If you want to boil the calcium in the bones, you need to use a lot of vinegar instead of water to stew the soup, but at this time, the taste of the bone soup is difficult for many people to accept.
Vegetables blanched in water to remove oxalic acid
Calcium supplementation can still be done
Although a small number of green leafy vegetables contain more oxalic acid, there are still many vegetables that are high in calcium and low in oxalic acid, such as rapeseed (including small rapeseed, chicken feathers), Chinese cabbage, kale, mustard green, green leaf cabbage, radish, etc., and the calcium content is quite considerable. Amaranth and spinach contain more oxalic acid, but as long as they are blanched in boiling water, most of the oxalic acid can be removed. Fortunately, calcium is insoluble in water, so blanched vegetables can still help us replenish calcium. In addition, green leafy vegetables are rich in magnesium and vitamin K, which are very helpful for bone health.
In addition, there are small fish and shrimp with bones and shells, and tahini sauce can also provide calcium. But they are relatively small in their dietary consumption, so they do not contribute much to calcium as the above three types of foods.
When it exceeds 500 mg, utilization decreases
A calcium tablet of 200-400 mg is preferably preferred
The amount of calcium that the human body can absorb and utilize at one time is not unlimited. When it exceeds 500 mg, utilization decreases. At the same time, too much calcium is also easy to cause adverse reactions in the gastrointestinal tract, and may also cause unstable blood calcium levels. Too much unabsorbed calcium also binds to fatty acids in the intestine, which can easily cause constipation. Long-term high-dose calcium supplementation may increase the risk of kidney stones. If the calcium of the daily diet has reached more than 800 mg, and more than 1000 mg of calcium tablets are supplemented every day, it will even increase the risk of cardiovascular disease. So, a reasonable amount is important!
The dietary calcium intake of Chinese residents is about 400 mg, choose a calcium supplement containing about 300 mg in a pill, take it twice a day, you can reach the total amount of 800 to 1000 mg per day, and it is not easy to cause adverse reactions.
People with indigestion, too little stomach acid, and sensitive stomach
Suitable for taking organic calcium acids
At present, the calcium tablets on the market mainly include calcium carbonate, calcium citrate and so on. To absorb the calcium in these tablets, people first need to release the calcium ions in the compound. Calcium carbonate is the most widely used because of its high calcium content and cheap price. However, calcium carbonate needs to react with stomach acid (hydrochloric acid) to release calcium ions and produce carbon dioxide gas.
For people with a healthy gastrointestinal tract, the acidity of gastric juice during digestion can easily reach the level of 2.5. However, for people with weak digestive capacity, patients after gastrointestinal surgery, or people who take antacids for a long time, gastric acid is consumed by calcium carbonate in part, and a large amount of gas is produced, which is easy to cause side effects of gas bloating and indigestion, hinder the digestion and absorption of nutrients in food, and affect human health. This side effect is more pronounced when the total amount of calcium carbonate is large.
Conversely, for people with insufficient stomach acid, part of the calcium carbonate can not fully release calcium ions, in an insoluble state directly into the intestine, and the pH of the small intestine can not allow calcium carbonate to release calcium ions, the result of insoluble calcium carbonate may be irritating to the intestinal mucosa.
In contrast, organic acid calcium such as calcium citrate generally does not bring this problem. Because they do not react with stomach acid to produce gas, and do not affect the activation of pepsin and the absorption of other nutrients because gastric acid is over-consumed.
Optional calcium tablets with vitamin D added
Calcium is more easily absorbed
Vitamin D is closely related to calcium metabolism, on the one hand, it promotes the absorption of calcium by the small intestine, and on the other hand, it promotes the absorption of minerals by bone, directly acting on the process of bone calcification. In addition, as mentioned earlier in the article, when vitamin D and calcium are supplemented together, it may play a beneficial role in preventing a variety of chronic diseases.
Vitamin D in foods is mainly found in high-cholesterol foods such as liver, egg yolks, fatty fish and cream, and daily intake is low. In the absence of clothing and sunscreen, when human skin is exposed to the sun, 7-dehydrocholesterol in the subcutaneous tissue will synthesize vitamin D, so adequate sun exposure is an important condition for the body to obtain vitamin D.
At present, the situation of vitamin D deficiency in Chinese residents is also very common, and many studies have suggested that vitamin D deficiency is associated with osteoporosis, low disease resistance, higher risk of diabetes, higher risk of obesity and even the risk of certain cancers.
In addition, there are some precautions for taking calcium tablets, such as we recommend taking calcium tablets at the time of meals or after a meal. Studies have shown that for people with weak digestive absorption capacity, calcium tablets taken during meals are more efficient than when they are on an empty stomach. At the same time, it is relatively difficult to cause gastrointestinal discomfort when taken at this time; do not take large doses of calcium tablets while taking supplements such as iron and zinc. In addition, it should be noted that too much calcium will hinder the absorption and utilization of trace elements such as iron and zinc. Therefore, when taking iron and zinc supplements, do not take calcium tablets at the same time, and do not drink milk. Consider taking calcium tablets after one meal and supplements containing iron or zinc after another meal. Text/Fan Zhihong
(Chief Expert of Science Communication, Doctor of Food Science)