The Canadian McGill University health website published an article on 2019-11-15 titled It Hasn’t Been a Good Year for Vitamin D. I translated it as follows:
There was a time when everyone was taking vitamin D to prevent everything from heart disease to cancer. But as one editor said recently, "and then had a random trial." In fact, 2019 is not a good year for Vitamin D. Many of the clinical trials published this year are negative.
First, a JAMA cardiac disease analysis conducted by 83,000 people from 21 random trials found that vitamin D cannot reduce the risk of cardiovascular disease, cardiac disease or death.
As far as cancer risks are concerned, a large VITAL study was published in the New England Medical Magazine in January. The study shows that vitamin D cannot prevent breast cancer, adenocarcinoma or kidney cancer, nor can it prevent cancer death. In April, AMATERASU random trial conducted a study of 417 patients with gastrointestinal cancer and found that giving them vitamin D could not improve five-year survival.
By summer, the D2d study published a study that vitamin D cannot reduce the risk of diabetes in patients with pre-diabetics. In addition, a research paper also provides six-year visits from a Denmark study, which proves that taking vitamin D by pregnant women does not reduce their children's risk of asthma. Finally, a recently published VITAL-DKD study found that vitamin D cannot help maintain kidney function in patients with diabetes.
Therefore, although vitamin D plays a role in promoting bone health, its benefits in many non-skeletal aspects are questionable. You might ask why a lot of research is so active in the beginning, but then it is so exhausting. This is because many studies are only relevant studies, that is, they find that people with low vitamin D levels in the blood have a higher chance of developing cancer, heart disease, etc. Therefore, it is reasonable to think that vitamin D deficiency is the cause of these diseases. However, it seems to be clear now, and it is actually other factors at work.
For example, people with chronic diseases such as cancer or CT inflammation may not eat healthily, so vitamin D's blood levels are lower. They may also be out too few because they are sick. In cases that are usually called "reverse causal relationship", it is not that vitamin D lack makes people sick, but that sick people are more likely to develop vitamin D lack. The story of Vitamin D is a great example of why it is necessary to conduct random trials to prove that something works before we spend millions (or even billions) of dollars on specific treatments. (Part 1: But unfortunately, billions of dollars a year are spent in vain)
The review may be too early for the year to be reviewed, and I don't think most people will remember that 2019 was the year when the Vitamin D tide ended. But for those who take vitamin D for no medical reasons, maybe this is a medicine you no longer need to take in 2020.
Original text: 2019 is not a good year for vitamin D