What is the difference between a calcium tablet that costs 2 yuan and one that costs 200 yuan?

When it comes to preventing osteoporosis, many people first think of calcium supplements and calcium tablets. However, there are many kinds of calcium tablets on the market, ranging from a few yuan a bottle to several hundred yuan a bottle.

The question is: What is the difference between these calcium supplements with such a big price difference? Which one is better to buy? What should I pay attention to when buying calcium supplements?

Photo/Meng Jian

Calcium deficiency in ordinary people

Increased risk of osteoporosis

Calcium is an important nutrient in our body. It participates in the formation of human bones, the reconstruction of bone tissue, and maintains the normal excitability of nerves and muscles. It also participates in regulating and maintaining cell functions, maintaining the acid-base balance of body fluids, blood coagulation, hormone secretion, etc.

In the human body, 99% of calcium is stored in bones and teeth, and the remaining 1% of calcium circulates in the blood as a component of blood calcium in the form of protein-bound calcium or ionized calcium.

If ordinary adults do not take in enough calcium, they will increase their risk of osteoporosis, rickets, and osteomalacia. The impact is even greater for pregnant women and breastfeeding mothers. Adolescents, in particular, who are in a critical period of growth and development, have a higher demand for calcium[1].

According to the recommendations of the "Dietary Reference Intake of Chinese Residents (2023)", the recommended daily calcium intake for ordinary adults, pregnant women and nursing mothers is 800 mg; the recommended daily calcium intake for adolescents aged 9 to 18 is 1000 mg.

Data show that the median calcium intake of Chinese residents is 328.3 mg/day, with a deficiency rate of 94.3%[3]. In other words, the daily calcium intake of the vast majority of Chinese residents through diet is insufficient . Under the premise of insufficient diet, appropriate calcium supplementation is beneficial to health.

2 and 200 calcium tablets

What exactly is the difference?

We can see calcium tablets with various ingredients in supermarkets, pharmacies or on the Internet. 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 a high calcium content, but its digestion requires a lot of stomach acid. Therefore, people with poor stomach function, stomach problems or long-term stomach acid who will have nausea and discomfort 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 more easily absorbed by the human body.

3. Amino Acid Chelated Calcium

Chelation is a production technology. Amino acid chelated calcium refers to the process of combining two amino acid molecules with one calcium ion through chelation technology. This can improve the absorption and utilization rate of minerals. It is characterized by light weight, easy solubility, easy absorption, and high absorption rate [4].

Whether it is a cheap calcium tablet or a high-priced calcium tablet, their core ingredients are the same, and there is no significant difference in the effect of calcium supplementation. When choosing a calcium supplement, you don’t need to pay too much attention to its chemical form.

A study used isotope dilution technology to analyze the bioavailability of six calcium supplements: calcium citrate, calcium lactate, calcium acetate, oyster shell powder, eggshell powder, and β-tricalcium phosphate. The results showed that the actual absorption rate and bioavailability of organic forms of calcium such as calcium citrate, calcium lactate, and calcium acetate were very high, with little difference [5].

It should be noted that the body's absorption of calcium is 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 a high-fiber diet lacks dairy products, calcium absorption is also affected.

Therefore, when supplementing calcium, do not take it at the same time as meals rich in phytic acid, oxalic acid, tannic acid, and high-fiber meals. At the same time, you can appropriately supplement vitamin D and vitamin K2 to help calcium absorption .

In addition, some calcium tablets, such as amino acid chelated calcium, added vitamin K2, etc., do have a higher absorption rate than other calcium tablets, but if the price is too expensive, you don't have to be too obsessed with it. Because even if the absorption rate is high, the body can't absorb too much.

Generally speaking, the body's calcium absorption rate decreases with age. Under normal circumstances, it is sufficient to choose ordinary calcium tablets.

1. Is it true that the higher the calcium content in calcium tablets, the better?

Let me give you the answer first: Of course not.

Some high-priced calcium tablets claim to have “high calcium content and better calcium supplementation effect”, such as 600 mg of calcium per tablet. But in fact, the higher the dosage of calcium tablets, the lower the absorption rate may be[6].

Studies have shown that the absorption rate of supplements is highest when the dose is 500 mg or less, with the human body absorbing approximately 36% of a 300 mg dose of calcium and 28% of a 1000 mg dose[7][8].

On the other hand, taking too much calcium can actually be harmful . Excessive calcium supplementation may not only cause muscle relaxation, constipation, nausea and other discomforts, but also interfere with zinc and iron absorption, 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 me give you the answer first: in terms of calcium supplementation effects, the quality of imported calcium tablets is not necessarily better than domestic ones.

Some high-priced calcium tablets will claim that they are "American calcium supplement experts", "selected from the world's 50 best calcium sources", "calcium supplements produced in the United States through a strict purification process and in accordance with FDA standards", etc. In fact, the key to the quality of calcium tablets is whether the manufacturer cuts corners, which has little to do with imports or domestic products.

As long as you buy it through the right channels, whether it is imported or domestically produced, there is usually no problem. All regular calcium tablets sold in my country must meet my country's standard requirements. As long as they are qualified in testing, their quality is guaranteed.

In general, when buying calcium tablets, we should choose the right ones instead of blindly pursuing expensive ones.

How to ensure adequate calcium intake?

It is ideal to supplement calcium from natural foods. If we consume enough calcium-rich foods such as dairy products, soy products, vegetables, nuts, etc. every day, we can get enough calcium and there is no need to take calcium tablets.

So, how do you ensure you get enough calcium?

1

Eat a balanced diet and try to get enough milk and dairy products

Milk and dairy products are the best choice for calcium supplementation. According to the "Balanced Diet Pagoda for Chinese Residents (2022)", the recommended daily intake of milk and dairy products for adults is 300-500 g.

However, most residents in China have insufficient intake of milk and dairy products. At present, the per capita dairy product consumption in China is less than 50 grams per day, which is only one-tenth of that in Europe and the United States. According to the "Scientific Research Report on the Dietary Guidelines for Chinese Residents (2021)", insufficient milk intake is the main reason for the high proportion of insufficient calcium intake among Chinese residents.

Photo/Meng Jian

2

If you don’t eat enough milk and dairy products, you should take calcium supplements

If dietary calcium intake is insufficient, it is recommended that you take appropriate calcium supplements.

For people with normal stomach function and normal digestion and absorption, calcium carbonate is recommended as the first choice, because it not only has a high calcium content and a high absorption rate, but is also safe and cost-effective.

For patients with poor stomach function, atrophic gastritis, or elderly people with poor digestive function, due to the lack of stomach acid, taking inorganic calcium such as calcium carbonate will be detrimental to calcium absorption. Organic calcium acid products such as calcium citrate can be given priority.

In addition, when taking calcium tablets, be sure to take the right amount . For optimal absorption, it is recommended that you do not take more than 500 mg each time. If you need to take more, it is recommended that you take it in multiple doses under the guidance of a doctor or nutritionist.

3

Pay attention to vitamin D supplement

Excessive sun protection is one of the important reasons for the lack of vitamin D in Chinese people. Vitamin D is added to calcium supplements nowadays. Vitamin D can help the absorption or utilization of calcium. Taking both together can help reduce the risk of osteoporosis. If vitamin D is not added to calcium supplements, it is recommended to take vitamin D alone.

References

[1] Qin Rui. Expert consensus on calcium nutrition for Chinese children (2019 edition)[J]. Chinese Journal of Maternal and Child Health Research, 2019, 30(03): 262-269.

[2] Dietary Reference Intakes for Chinese Residents (2023)

[3] Huang F, Wang Z, Zhang J, Du W, Su C, Jiang H, Jia X, Ouyang Y, Wang Y, Li L, Zhang B, Wang H. Dietary calcium intake and food sources among Chinese adults in CNTCS. PLoS One. 2018 Oct 1;13(10):e0205045. doi: 10.1371/journal.pone.0205045. PMID: 30273413; PMCID: PMC6166981.

[4] Jian Lingyan, He Xiaojing, Zhao Limei, et al. Absorption and bioequivalence of compound amino acid chelated calcium in humans[J]. Chinese Journal of Hospital Pharmacy, 2009, 29(12): 983-986.

[5] Bao Shanfen, W. Windisch, M. Kirchgessner. Comparison of bioavailability of six different calcium preparations using isotope dilution technique[J]. Chinese Journal of Osteoporosis, 2007(06):377-380.

[6] Calcium - Consumer (nih.gov)

[7] Institute of Medicine SCotSEoDR, Intakes,. Dietary Reference Intakes for Calcium, Phosphorus, Magnesium, Vitamin D, and Fluoride. Washington, DC: National Academies Press; 1997.

[8] Heaney RP, Dowell MS, Barger-Lux MJ. Absorption of calcium as the carbonate and citrate salts, with some observations on method. Osteoporos Int 1999;9:19-23.

Planning and production

Author: Ruan Guangfeng, Deputy Director of Kexin Food and Health Information Exchange Center

Review丨Zhong Kai, Director of Kexin Food and Health Information Exchange Center

Planning丨Lin Lin

Editor: Wang Mengru

Proofread by Xu Lailinlin