Pregnant women need 40 grams of calcium throughout pregnancy, most of which are accumulated within 3 months after pregnancy. You need to supplement 1.2g of calcium every day for three months. Milk is rich in calcium, 1 kg milk contains calcium1.2g. In developed countries, 30% people live on milk, and pregnant women are basically not short of calcium. If women in China can eat 250-500 grams of milk every day, the calcium intake is insufficient, but there is enough calcium in the bone marrow of pregnant women, which can be easily mobilized from the bone marrow, and at the same time, the calcium absorption of pregnant women can be enhanced. Therefore, pregnant women with their first child generally do not lack calcium, and newborns do not lack calcium. In the third trimester, some pregnant women have lower limb spasms, and calcium supplementation can make the symptoms disappear. General calcium supplementation methods can start from the following three aspects.

(1) Drinking 250 grams of milk every morning and evening can supplement calcium by about 600 mg.

(2) Eat foods rich in calcium, such as bone soup, fish and shrimp.

(3) Calcium supplement, preferably absorbable calcium.

If the above (1)(2) is enough, calcium supplementation is basically not needed; Pregnant women who don't like milk can supplement 600 mg of easily absorbed calcium every day. /(knitting dolls)

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Dosage and method of calcium supplementation

Calcium requirements should consider different physiological conditions, such as the increase of calcium requirements of infants, children and adolescents, and the increase of calcium requirements of pregnant women and lactating mothers under special physiological conditions. The recommended calcium supply in China is 400m g for infants in the first 6 months, 600m g for infants in 6- 12 months, 600 mg for infants under 2 years old and 800m g for infants aged 3-9 years old. 10-1000mg12 years old13-1200mg15-year-old adult 800m g pregnant woman1000-1.

When supplementing calcium, people first think of food-borne calcium. Milk and dairy products are the main sources of calcium in food, which are not only rich in content, but also high in absorption rate. Green vegetables, such as cabbage and cauliflower, are also good sources of calcium, because they are rich in calcium and less oxalic acid. Shrimp skin is particularly rich in calcium; The calcium content in tofu and dried beancurd is high, mainly because gypsum (calcium sulfate) is added in the production process, so the calcium content is much higher than that in beans.

In addition, eating fried fish with bones, or adding vinegar when stewing ribs soup, can promote the dissolution of calcium in bones, and can also be used as a good source of calcium in the diet. Bone meal and eggshell powder are also good calcium supplements. Calcium can be supplemented when necessary, but it must be reasonable, scientific and standardized.

Matters needing attention in calcium supplementation

At present, there are many calcium agents in the domestic market, which are overwhelming and advertised, but everyone must use them scientifically and reasonably.

Selection of calcium agent type: (1). At present, the dosage of calcium agent in the market is mainly active calcium, but it is reported that arsenic, mercury, lead and chromium are detected in its finished products, which is also very toxic, so it is necessary to evaluate its safety. (2) Among fortified foods, calcium carbonate is the most used. Although the absorption and utilization of calcium carbonate vary greatly among individuals, the average utilization rate of people is not significantly different from other forms of calcium and dairy products. Because the dissolution of calcium carbonate requires low P H, it is not suitable for patients with gastric acid deficiency. (3) Organic acid calcium, such as calcium citrate, although low in calcium content, is more soluble than calcium carbonate, and is suitable for patients with gastric acid deficiency. (4) Calcium phosphate can be used as a fortifier in food or calcium futures, but this kind of product is not easy to dissolve and contains a considerable amount of phosphorus, so it is not suitable for patients with renal failure. In addition, many calcium products contain vitamin D, magnesium and other minerals, so care should be taken when these products are used in patients with renal insufficiency or patients with limited intake of some nutrients. At present, a new calcium agent, calcium L- threonate, has appeared. The salt obtained by combining bioactive anions with calcium has a large peak time, half-life and total bioavailability in vivo.

Selection of calcium dosage: the absorption of calcium increases with the increase of calcium intake, but after reaching a certain value, the intake increases again, but the absorption of calcium no longer increases. We also pay attention to two problems when choosing dosage: (1) is the individual needs of the body, such as the differences of age, gender and national habits; (2) Considering the intake of calcium in food, the average intake of urban population in China is 490 mg/d ... In the choice of calcium dosage, we should get out of the misunderstanding that the more the better. In addition, in the process of calcium supplementation, we should also pay full attention to the following issues. (1), the adverse reaction of calcium. The dosage of calcium is 1-2mg/d, which can be taken by ordinary people for a long time with few adverse reactions. In some cases, constipation, intestinal swelling and flatulence can be seen. For the elderly and patients with genetic metabolic defects, excessive supplementation can lead to hypercalcemia and contribute to the formation of kidney calculi. Excessive use of calcium preparations containing vitamin D or other elements will lead to vitamin D poisoning or other syndromes; (2) The effect of food on calcium absorption. Food containing too much phosphate or oxalate can form insoluble calcium salt with calcium; Excessive fat can combine with calcium to form insoluble "calcium soap", both of which will reduce the absorption of calcium. (3) When supplementing calcium, vitamin D must be carefully supplemented. Many people know that vitamin D can promote the absorption of calcium, so vitamin D supplementation is unlimited. However, excessive intake of vitamin D is easy to accumulate in the body due to its long metabolism time, leading to poisoning. For ordinary adults, regular exposure to the sun is the best source of vitamin D, and there is generally no need to supplement it. For infants and young children, sunbathing is the best way for the body to synthesize vitamin D. Unless they are seriously deficient in vitamin D, they can take it at the lower limit of the doctor's guidance, but not for a long time. When supplementing calcium, you can refer to the following principles: First, try to supplement calcium from natural foods instead of pills, and the diet structure is more and more reasonable; Second, calcium is not as expensive as possible; Third, calcium supplementation during meals can enhance the body's absorption of calcium; Fourth, the amount of calcium supplementation should not exceed 500 m g. Fifth, if you are taking thyroid hormones, tetracycline, corticosteroids and other drugs, you need to consult a doctor in advance and make calcium supplements under the guidance of a doctor.