Vitamin D: a fake vitamin and its non-existent effect

Many people believe that vitamin D supplementation by drinking more milk and taking supplements can prevent osteoporosis and reduce the incidence of fractures. But how much vitamin D is "sufficient"? Tim Spector, a professor of genetic epidemiology at King's College London, points out that vitamin D is by no means much better. Many new studies have confirmed that healthy people do not have vitamin D supplementation, and from the current point of view, it is not a vitamin, but more like a hormone.

After a century of vitamin discovery, we still have a soft spot for it, and half of people in the United States and the United Kingdom are taking supplements. Among them, “Sunshine Vitamin” is the most popular vitamin D, and it has proven to be the most beneficial to the human body. Governments, including the UK, have said that the evidence that vitamin D is good for health is convincing and that each adult needs to take this supplement for at least six months a year.

Vitamin D was originally used in the Victorian era to treat childhood caries in urban poor areas and is now routinely used to prevent and treat fragile bone diseases (osteoporosis) and fractures. There is also a series of observational studies that suggest it is associated with a reduction in the risk of more than 100 common diseases, from depression to cancer.

Recently, the largest clinical study on the effectiveness of vitamin D in preventing fractures was published in the British Medical Journal (BMJ). The data were from 23 groups in many countries, covering more than 500,000 people and about 188,000 fractures. . Because vitamin D levels are strongly influenced by genes, researchers use genetic markers to assess vitamin D blood levels. This method, called Mendelian randomisation, avoids the normal bias of observational research, such as confusing the cause and consequences of the disease or being affected by other related health behaviors (so-called "confounding factors").

The results of the study showed no correlation between vitamin D levels in life and fracture risk. This latest study contradicts the government's recommendations to the public, but is consistent with a large number of early clinical trials.

In 2014, a review and meta-analysis of 31 vitamin D supplement trials found that vitamin D had no effect on all fractures. Our strong belief in the benefits of vitamin D is largely due to the study of sanator supplements in the 1980s, which have never been repeated and are likely to be flawed.

In a later meta-analysis of 33 randomized trials of more than 50,000 older adults, supplementation with calcium or vitamin D had no effect on the incidence of fractures and had no significant benefit in improving muscle strength and athletic performance.

So, if all the data indicates that vitamin D does not prevent fractures, why worry about those with low levels of vitamins in the blood? Vitamin D deficiency has become a modern epidemic. It is reported that one in five British and American populations have lower levels of vitamin D. Are they really more susceptible to other diseases and cancers?

"Vitamin D deficiency" is a false proposition

There is no consensus on the definition of vitamin D deficiency. In the absence of international standards, the lack of levels is arbitrarily assessed, and in the United States, the use of different units of measurement also creates confusion. The "normal" level of vitamin D ranges from 50 to 80 nanomoles per liter of blood, but recent studies have suggested that 30 nmol is sufficient.

Although clinically defined vitamin D deficiency (<10 nmol) is usually clear, erroneously labeling millions of people with vitamin D deficiency can cause psychological stress and over-medication. Most people think that calcium and vitamin D are safe, and the more you take, the better. But when studies have shown that calcium supplements are not only unable to prevent fractures, but can also lead to heart disease, my clinical practice has also changed. The number of prescriptions for such supplements is also decreasing.

Vitamin D is fat-soluble, so high concentrations of vitamin D can accumulate in the body. Although the recommended dose of supplements is usually moderate (10 micrograms or 400 international units (IU)), some people will inevitably consume cod liver oil capsules, fortified milk, orange juice, bread and other sources of vitamin D, so it will inevitably Take too much. Even more worrisome is the fact that more and more 4,000-20000 IU of high-dose supplements are being purchased on the Internet.

In my clinic and elsewhere, patients with high levels of vitamin D in the blood (over 100 nmol) are already common, and reports of overdose leading to poisoning are increasing. Some randomized trials have shown that patients with high levels of vitamin D in their blood or taking large doses of vitamin D (over 800 IU) unexpectedly increase the risk of falls and fractures. Vitamin D is by no means safe.

Vitamin D should not be recommended for use in other settings, and positive studies published on 137 diseases are considered to be counterfeit. It is widely believed that vitamin D supplements can prevent cardiovascular disease, but meta-analysis and large-scale genetic Mendelian randomization studies rule out this possibility.

You can get enough vitamin D from food and sunlight. | Image source: Pixabay

Pseudo disease

We have created a pseudo-disease and this concept has been promoted by vitamin companies, patient groups, food manufacturers, public health departments and charities. Everyone believes in magical vitamin pills and feels "they are working."

Although vitamin D is highly regarded, it should not be called vitamins today because the body can synthesize vitamin D on the skin and it is a steroid precursor. (Editor's Note: The active form of vitamin D is called calcitriol, a steroid hormone that plays an important role in regulating blood calcium and blood phosphorus levels.) Healthy people should take a small amount of sunlight and fish, oil, and daily. Vitamin D is consumed in foods such as mushrooms and dairy products, rather than relying on imposters.

We should also believe that the evolution of thousands of years has enabled us to cope with the natural decline in vitamin D levels in winter and will not easily break our limbs. About half of people take vitamins daily, which has no benefit, and there is growing evidence that it is harmful. The trend of adding uncontrolled vitamins to processed foods worldwide is now strongly questioned.

Although vitamin D still plays a very limited role in medicine for the treatment of patients who are severely deficient or bedridden, others should avoid using this steroid to "treat" this pseudo-disease and develop a healthy Lifestyle, more sun. More importantly, save money and energy and eat nutritious “real food”.