In the outpatient department, I occasionally encounter patients who come to seek treatment and complain:
Recently, my legs and feet are old cramps, or I feel numb, but I feel uncomfortable. Doctor, am I short of calcium? Give me some calcium tablets.
Of course, I usually ignore the latter sentence and then ask him if he has other symptoms and a history of previous diseases. Looking through his case, I found that he had undergone thyroid surgery before. One of the complications of thyroid surgery is parathyroid gland injury, resulting in temporary or permanent hypocalcemia.
Why does parathyroid gland injury lead to hypocalcemia?
First of all, let’s talk about the function of parathyroid gland.
Parathyroid glands are located behind the thyroid gland at the neck. Some people’s parathyroid glands can grow inside the thyroid gland or other parts of the neck due to congenital anatomical position variation. Such parathyroid glands are called [vagal parathyroid glands].
Parathyroid hormone (PTH) is mainly secreted by parathyroid gland. The function of PTH is an important hormone that manages calcium and phosphorus metabolism. It can promote bone absorption, maintain a certain blood calcium concentration, increase calcium absorption in intestinal tract and reduce calcium loss from body.
In short, PTH can keep the blood calcium of human body at a certain level and maintain the normal calcium and phosphorus metabolism process of human body.
However, in people with parathyroid gland injury, PTH secretion is reduced, which is not enough to maintain normal blood calcium concentration, thus causing a series of symptoms such as cramps and numbness caused by low calcium.
As the old saying goes, capture the thief first and capture the king first. Although we understand that the reduction of PTH is the main culprit of hypocalcemia, on the one hand, there is no targeted drug to supplement PTH in China, and on the other hand PTH is a peptide hormone, so there will be more restrictions on preservation and use and the cost will be high.
Therefore, in most cases, we adopt symptomatic treatment, that is, calcium supplement and vitamin D supplement.
Calcium supplement is exquisite, don’t forget vitamin D
Hypocalcemia caused by hypoparathyroidism places more emphasis on adequate supplement of vitamin D preparations.
1. Calcium, how much do you need to supplement every day?
Generally speaking, it is enough for adults to supplement 1,000-2,000 mg of calcium every day. It should be noted that this refers to the calcium content, not the weight of a tablet during normal calcium supplement, but the calcium content in it.
For example, a calcium tablet weighs 1 g, if its main component is calcium carbonate, then the calcium content in it may be less than 400 mg.
2. Recommended daily vitamin D
Vitamin D can promote the absorption and utilization of calcium in intestinal tract, and PTH is also needed to play this role.
People with insufficient parathyroid secretion, without this strong help, need to better absorb calcium:
- More people and more strength, increase vitamin D supplement; Avoid the threshold of parathyroid gland and choose active vitamin D preparations, commonly used calcitriol and alfacalcitol.
Generally speaking, adults receive 1-2 g of active vitamin D preparations every day.
How to better grasp the supplement amount of calcium and vitamin D preparations?
It is suggested to check blood calcium and phosphorus after taking calcium and vitamin D preparations stably for 3-5 days:
- The target of blood calcium is 2.1 ~ 2.3 mmol/L; The target of blood phosphorus is 1.2 ~ 1.5 mmol/L.
In these two goals, blood calcium is satisfied first.
If the standard is not met, the doctor will adjust the supplement of calcium and vitamin D according to the specific situation, and gradually make small adjustments according to the detection values of blood calcium and blood phosphorus, so that the blood calcium and blood phosphorus can reach the treatment control target.