A friend asked me whether it was true in WeChat and private letters.
First of all, this statement does have a source, from a recently published scientific research paper.
The reason why we say "derivative" is because the paper does not directly give the above shocking conclusions, so this is another masterpiece of the "headline party" from the media.
The core ideas about calcium and vitamin D in the paper are roughly as follows:
1. Supplementing calcium in excess of 1000 mg per day may increase the risk of cancer unless calcium comes from food instead of dietary supplements.
2. People who are not deficient in vitamin D may increase all-cause mortality (including cancer) if they take 400 units of vitamin D every day.
Dietary supplements seem to have nothing to do with the health level of Americans.
How to treat these three viewpoints?
First of all, the results of this study are just the opinions of one family, and further research and verification are needed.
Secondly, it is aimed at Americans, and nutrition research is related to many factors, such as national economic development level, social background, dietary structure and so on, and cannot be directly copied to China.
1. About 1000 mg of calcium.
The biggest difference between the United States and China is the consumption of dairy products.
You know, dairy products are an important source of calcium, and 100 ml of milk is equivalent to about 100 mg of calcium.
The dietary guidelines in the United States recommend that each person drink 3 cups of milk a day, which is about 700 ml, which is 700 mg of calcium.
Adding calcium from other dietary sources, the average daily calcium intake of Americans can reach about 1000 mg.
On this basis, it is unnecessary to supplement more than 1000 mg of calcium, which does pose health risks.
This view has existed for a long time, because the "tolerable maximum intake" of calcium is 2000 mg.
In other words, generally speaking, as long as the daily calcium supplement and the calcium in food do not exceed 2000 mg, the advantages outweigh the disadvantages.
In contrast to China, China's dietary guidelines suggest drinking a glass of milk every day, which is about 300 grams, that is, 300 milligrams of calcium.
In fact, many people in China don't drink milk. Therefore, the average daily dietary calcium intake is only 300-400 mg.
The recommended daily intake of calcium for normal adults is 800- 1000mg (more for pregnant women). Therefore, China people's proper calcium supplementation is definitely more beneficial than harmful.
Of course, if you have the habit of drinking milk, you can choose it according to your own situation. Generally, the daily calcium intake is not less than 800 and not more than 2000.
2. about 400 units of vitamin d.
The above paper means that people who are not short of vitamin D may supplement 400 extra units of vitamin D, which is not necessarily good or bad.
You said, if you don't lack it, you will make it up. Is there no place to spend more money?
Do people in China lack vitamin D?
In fact, there is a shortage, and there are still many people, especially children and adolescents.
For example, in a study conducted by Shanxi Children's Hospital and Maternal and Child Health Hospital in 20 18, 29.7% of children aged 9- 16 were vitamin D deficient and 35.7% were vitamin D deficient.
There are too few outdoor activities, and the lack of sunshine is the most important factor, so the lack of vitamin D in middle school students is more serious than that in primary school students (there may also be growth and development factors).
Adults are no better. China people's pursuit of whitening and sun protection is in sharp contrast to American people's pursuit of bronzed skin.
It's already very insufficient. Is there a problem with adding one point?
It is useless to eat dietary supplements.
For Americans, their biggest problem is that they have a nutritious diet and eat a lot of supplements, which is of course useless and may even be harmful.
For China people, although there is overall overnutrition (reflected in overweight, obesity and soaring three highs), some micronutrients are still lacking, including calcium, iron, vitamin D, vitamin B and vitamin E. The advantages of targeted and appropriate supplementation outweigh the disadvantages.
In addition, due to the uneven level of economic development, malnutrition among children and adolescents in some underdeveloped areas has become a very prominent public health problem.
At present, the free nutrition package provided by the state for these places is a typical social welfare project, with less investment, great income and lifelong benefit.
Do you think eating it will help?
In a word, there are many studies on dietary supplements, and the papers that have been circulated on the Internet this time have no subversive conclusions.
No matter what kind of nutrition, it is not good to eat too much, but at least under the current nutritional situation in China, it is still very difficult to eat something wrong. Just eat it if you want.
For consumers in China, it will be more practical and instructive to suggest that more attention should be paid to the study of China people by China scholars in the future.