Immune vitamins, anti-cancer vitamins
Vitamin D = immune vitamin
One of the most important reasons vitamin D has become so important today is because it boosts immunity. Recently, research results are coming out that vitamin D is involved in preventing various cancers and helps to overcome infectious diseases such as colds and flu. This is why vitamin D is called the immune vitamin or anti-cancer vitamin. Interestingly, there are vitamin D receptors in various white blood cells that are in charge of immunity, so they accept vitamin D entering the body. And white blood cells suppress inflammatory substances in the body through vitamin D and produce immune proteins that can kill viruses and bacteria. In addition, vitamin D promotes cell differentiation to prevent immature cells from becoming cancerous cells, and induces apoptosis so that old and diseased cells die on their own.
Effective in preventing diabetes
There is a lot of evidence that vitamin D has other health benefits. Let's look at type 1 diabetes in children. Type 1 diabetes is 400 times more common in Finland, a country with less sunlight than in Venezuela, a country with more sunlight. In Finland, when vitamin D was administered to 10,000 newborns soon after birth, the incidence of type 1 diabetes was reduced by 90% compared to newborns not receiving vitamin D. Vitamin D's immunomodulatory action appears to have helped prevent the autoimmune disease type 1 diabetes.
Effect on Infectious Diseases
The same goes for respiratory infections such as the flu. Influenza is common in winter, and there are reports that children with rickets and adults with low blood vitamin D levels are more likely to catch colds. A randomized clinical study on the efficacy of vitamin D was conducted in Japan. In a study of 167 children given 1,200 IU of vitamin D for 4 months and 167 control subjects given a placebo, a 42% reduction in influenza was observed in the vitamin D group (Am J of Clin Nutr, 2010). It means that there was a scientific basis for the old people's words that the more they burn their children in the midsummer sunlight, the less they will catch a cold in winter. In addition, studies have shown that vitamin D reduces the risk of heart attack by nearly two times, vitamin D deficiency is prone to dementia, and vitamin D preparations reduce the possibility of miscarriage.
As far as reducing mortality...?
Vitamin D has an effect on reducing mortality as well as various diseases. In a meta-analysis of 18 randomized clinical studies involving 60,000 participants, taking vitamin D supplements at 400 to 800 IU daily for an average of 5 years reduced total mortality by 7% (Arch Intern Med, 2007). In a meta-analysis by the Harvard School of Public Health, taking vitamin D supplements for 2 to 7 years reduced cancer mortality by 12%. Given that mortality is the most mobile health indicator, the fact that a non-drug vitamin D formulation reduced mortality suggests that vitamin D is powerfully beneficial to our health in all directions.
Vitamin D = anti-cancer vitamin
The anti-cancer activity of vitamin D was known in the 1980s when a study was published showing that people living in high latitudes had a high risk of colorectal cancer. The higher the latitude, the less sunlight there is, so it is easy to lack vitamin D, which is why various cancers such as colorectal cancer, breast cancer, and prostate cancer occur. Since then, many studies have begun to reveal the cancer-preventive effects of vitamin D one after another. Studies have shown that it reduces not only the chances of getting cancer (cancer incidence), but also the chance of dying from cancer (cancer mortality). In particular, colorectal cancer showed a phenomenon inversely proportional to vitamin D blood level. For example, a vitamin D deficiency doubles the risk of colorectal cancer. This strongly suggests that there is a causal relationship between vitamin D and colorectal cancer, rather than just a statistical association.
In Korea, where colorectal cancer is particularly prevalent,...
These findings are of great significance in Korea as well. This is because colorectal cancer is rapidly increasing in Korea. It has already overtaken the United States in 2008 in the incidence of colorectal cancer, and currently has the disgrace of being ranked number one in the incidence of colorectal cancer worldwide. The main reason for the explosive increase in the incidence of colorectal cancer is that screening, such as colonoscopy, has become more active and more patients have been identified than before. However, I believe that Korea is largely to blame for the fact that our country is the most deficient in vitamin D in the world. Breast cancer as well as colorectal cancer are strongly related to vitamin D. Breast cancer in Korean women has a unique pattern. In Case of Western women, breast cancer occurs more often as they get older, but in Korea, it is rather common in relatively young women in their 40s. It is estimated that the main cause is a lack of vitamin D due to excessive diet and blocking sunlight.
Cancer and related research still needed
The relationship between vitamin D and cancer requires ongoing research. This is because large-scale randomized clinical trials that prove a causal relationship are still lacking. Harvard University School of Public Health is currently conducting a large-scale randomized clinical study to prove the anti-cancer effect of vitamin D. This is a study in which 2,000 IU of vitamin D is administered daily to 20,000 healthy adults and changes in the incidence of various cancers are observed. Final results are expected in several years. Until more evidence is available, it should not be conclusively stated that vitamin D prevents cancer. This is because cancer is a very difficult and complex disease involving complex mechanisms, and the approach of solving it with just one vitamin D is difficult.
However, at least based on the findings so far, vitamin D supplementation is one of the easiest and most powerful ways to fight cancer. Vitamin D preparations are very easy to synthesize and very inexpensive. You can buy a month's supply for a few thousand won. There are few side effects if you follow the usage and dosage when ingesting. So there is no reason to wait for a final, authoritative interpretation of vitamin D's efficacy. This is why the Harvard University Food Pyramid also recommends taking a separate vitamin D supplement in addition to a daily multivitamin.
Esther Lyuh, Doctor of Preventive Medicine, Seoul National University