October 20th every year is World Osteoporosis Day. When it comes to preventing osteoporosis, many people first think of taking calcium supplements and buying calcium tablets. However, there are many types of calcium tablets on the market, ranging from a few yuan a bottle to a few hundred yuan a bottle. Here comes the question: What is the difference between these calcium tablets with such huge price differences? Which one is better to buy? What should you pay attention to when buying calcium tablets?
Calcium deficiency in ordinary people increases the risk of osteoporosis
Calcium is an important nutrient in our body. It participates in the formation of human bones and the reconstruction of bone tissue. It also maintains the normal excitability of neuromuscles. It also participates in regulating and maintaining cell functions, maintaining acid-base balance of body fluids, blood coagulation, and hormone secretion.
In the human body, 99% of calcium is mainly stored in bones and teeth, and the remaining 1% circulates in the blood as a blood calcium component in the form of protein-bound calcium or ionized calcium.
Insufficient calcium intake in ordinary adults will increase the risk of osteoporosis, rickets, and osteomalacia. For pregnant and breastfeeding mothers, the impact is even greater. Especially adolescents who are in a critical period of growth and development have a higher demand for calcium [1].
According to the recommendations of the "Reference Intake of Dietary Nutrients for Chinese Residents (2023)", the recommended daily calcium intake for ordinary adults, pregnant women, and wet nurses is 800 mg; the recommended daily calcium intake for adolescents aged 9 to 18 years is 1,000 mg.
According to the latest data, the median calcium intake of Chinese residents is 328.3 mg/day, and the deficiency rate is 94.3% [3]. In other words, the vast majority of Chinese residents do not get enough calcium through diet. On the premise of insufficient diet, proper calcium supplementation is beneficial to health.
What is the difference between 2 pieces and 200 pieces of calcium tablets?
We can see calcium tablets with various ingredients in supermarkets, pharmacies or online. No matter how cool the packaging is, there are only three categories: organic calcium, inorganic calcium and chelated calcium.
1. Inorganic calcium
Inorganic calcium mainly includes calcium carbonate, calcium chloride and calcium phosphate. The biggest feature of inorganic calcium is that it is cheap and has high calcium content, but its digestion requires a large amount of gastric acid. Therefore, people with poor gastric function, stomach problems, or friends who suffer from nausea and discomfort due to long-term gastric acidity should avoid choosing it.
2.Organic calcium
Organic calcium includes calcium citrate, calcium acetate, calcium lactate, calcium gluconate, calcium citrate, etc. The absorption of organic calcium does not require the participation of gastric acid. Although the content is not as good as inorganic calcium, it is easier to be absorbed by the body.
3. Amino acid chelated calcium
Chelation is a production technology. Amino acid chelated calcium means that each two amino acid molecules and one calcium ion are chelated together through chelation technology. This can improve the absorption and utilization rate of minerals. It is characterized by being light in weight, easy to dissolve, easy to absorb, and has a high absorption rate [4].
Whether it is cheap calcium tablets or high-priced calcium tablets, their core ingredients are the same, and there is no obvious difference in the effect of calcium supplementation. When everyone chooses calcium supplements, they don’t need to pay too much attention to its chemical form.
One study used isotope dilution technology to analyze the bioavailability of six calcium agents: calcium citrate, calcium lactate, calcium acetate, oyster shell powder, eggshell powder and beta-tricalcium phosphate. It was found that the true absorption rate and bioavailability of organic forms of calcium such as calcium citrate, calcium lactate and calcium acetate are very high, and the difference is not significant [5].
It should be noted that the body's absorption of calcium will be affected by many factors. For example, phytic acid, oxalic acid, and tannic acid can combine with calcium to form insoluble complexes, reducing calcium absorption; if there is a lack of high-fiber diets such as dairy products, calcium absorption will also be affected.
Therefore, when supplementing calcium, do not eat at the same time as meals rich in phytic acid, oxalic acid, tannic acid, and high fiber. At the same time, appropriate supplements of vitamin D and vitamin K2 can help with calcium absorption.
There are also some calcium tablets, such as amino acid chelated calcium, added vitamin K2, etc. Compared to other forms of calcium, the absorption rate is indeed higher, but if the price is too expensive, don’t be too obsessed. Because although the absorption rate is high, the body cannot absorb too much.
Generally speaking, the body's absorption rate of calcium decreases with age. Under normal circumstances, ordinary calcium tablets are enough.
1. Is the higher the calcium content of calcium tablets, the better?
Let me start with the answer: Of course not.
Some high-priced calcium tablets will say that they have "high calcium content and better calcium supplement effect", for example, each tablet contains 600mg of calcium. But in fact, the higher the dose of calcium tablets, the absorption rate may decrease [6].
Studies have pointed out that the absorption rate of supplements is highest at 500mg or less, and the human body can absorb approximately 36% of a 300mg calcium dose and 28% of a 1000mg dose [7][8].
On the other hand, taking too much calcium tablets can be harmful. Excessive calcium supplementation may not only cause muscle relaxation, constipation, nausea and other discomforts, but may also interfere with the absorption of zinc and iron, causing zinc and iron deficiency. Severe excessive calcium intake can also cause hypercalcemia and hypercalciuria, leading to kidney stones, vascular calcification, and even renal failure.
2. Are imported calcium tablets really better?
Let’s talk about the answer first: In terms of calcium supplementation effect, the quality of imported calcium tablets is not necessarily better than that of domestic products.
Some high-priced calcium tablets will say that they are "American calcium supplement experts", "selected from the 50 best calcium sources in the world", "calcium supplements produced in the United States according to FDA standards through strict purification processes" and so on. In fact, the key to affecting the quality of calcium tablets is whether the manufacturer cuts corners and has little to do with imports and domestic production.
As long as you buy from the correct channels, whether imported or domestic, there is usually no problem. All regular calcium tablet products sold in my country must meet my country's standard requirements. As long as they are qualified calcium tablets, their quality is guaranteed.
In general, when we buy calcium tablets, we should choose the right ones instead of blindly pursuing expensive ones.
How to ensure you get enough calcium?
Calcium supplementation from natural foods is ideal. If we consume enough calcium-rich foods such as dairy products, soy products, vegetables, nuts and so on every day, we can get enough calcium and there is no need to take additional calcium tablets.
So, how to ensure that you are getting enough calcium?
1. Eat a balanced diet and try to eat enough milk and dairy products
Milk and milk products are the best choices for calcium supplementation. According to the recommendations of the "Balanced Diet Pagoda for Chinese Residents (2022)", the recommended daily amount of milk and dairy products for adults is 300 to 500g.
However, most residents in my country have the problem of insufficient intake of milk and dairy products. Currently, the per capita consumption of dairy products in my country is less than 50 grams/day, which is only one-tenth of that in Europe and the United States. According to the "Scientific Research Report on Dietary Guidelines for Chinese Residents (2021)", insufficient milk intake is the main reason for the high proportion of insufficient calcium intake among Chinese residents.
2. If you don’t eat enough milk and dairy products, take appropriate calcium supplements.
When dietary calcium intake is insufficient, it is recommended that you supplement calcium tablets appropriately.
For people with normal gastric function and normal digestion and absorption, calcium carbonate is recommended as the first choice because it not only has high calcium content and high absorption rate, but is also safe and cost-effective.
For patients with poor gastric function, atrophic gastritis, or the elderly with poor digestive function, due to lack of gastric acid, taking inorganic calcium such as calcium carbonate will not be conducive to calcium absorption. Products with organic acid calcium such as calcium citrate can be preferred.
In addition, when taking calcium tablets, be sure to pay attention to the appropriate amount. For optimal absorption, it is recommended not to exceed 500 mg per serving. If you need to eat more, it is recommended to eat it in multiple portions under the guidance of a doctor or nutritionist.
3. Pay attention to supplementing vitamin D
Excessive sun protection is one of the important reasons for vitamin D deficiency in Chinese people. Vitamin D is added to today’s calcium supplement products. Vitamin D can help with the absorption or utilization of calcium, and taking both together can help reduce the risk of osteoporosis. If vitamin D is not added to the calcium supplement product, it is recommended to take vitamin D alone.
References
[1] Qin Rui. Expert consensus on calcium nutrition for Chinese children (2019 edition) [J]. Chinese Maternal and Child Health Research, 2019, 30(03): 262-269.
[2] Reference intake of dietary nutrients for Chinese residents (2023)
[3]HuangF,WangZ,ZhangJ,DuW,SuC,JiangH,JiaX,OuyangY,WangY,LiL,ZhangB,WangH. DietarycalciumintakeandfoodsourcesamongCh ineseadultsinCNTCS.PLoSOne.2018Oct1;13(10):e0205045.doi:10.1371/journal.pone.0205045.PMID:30273413;PMCID:PMC6166981.
[4] Jian Lingyan, He Xiaojing, Zhao Limei, et al. Human absorption and bioequivalence of compound amino acid chelated calcium [J]. Chinese Journal of Hospital Pharmacy, 2009, 29(12): 983-986.