Vitamin D deficiencies in Tokyo
Study of blood tests in Tokyo finds 98% as having vitamin D deficiencies
According to a recent study by Japanese Jikei University School of Medicine, which was announced on June 5, a whopping 98 percent of physical examination results in Tokyo showed a lack of vitamin D.
Vitamin D is the one that helps the body to properly take in calcium, among other minerals, which leads to strong bones. It can be taken into the body in three ways: through the absorption of sunlight, through eating certain animal products such as oily fish, and through eating certain plant products such as mushrooms.
The actual range of foods that contain significant amounts of vitamin D are actually rather few and far between and include fish such as salmon, mackerel, and tuna or mushrooms like shiitake. As luck would have it, these are all rather common foods in Japanese cuisine.
However, when Jikei University examined the blood tests of about 5,500 adult men and women from the year before the pandemic, they found that 98 percent of them had lower than the recommended levels of vitamin D. In particular, the type of vitamin D derived from mushrooms was lacking in blood samples.
The deficiencies appear to be more prevalent in younger people as well, which is causing the researchers to suspect a westernization of diets to be a contributing factor.
If that’s the case, then it begs the question of why people in Western countries aren’t all walking around with rickets. One reason is that other countries tend to compensate by fortifying other more commonly consumed foods with the vitamin, such as North America which has a custom of putting vitamin D in milk.
On the other hand, Japanese milk is not normally fortified with vitamin D, except for a few specialty brands. So, while a Western diet may be gradually making its way into Japanese society, the appropriate countermeasures that such a diet requires have not.
This is still all just speculation though, and a lot of comments online seem to feel that a lack of sunlight is a more widespread problem than consumption of mushrooms among residents of Japan.
Researchers agree that the deficiency is partly due to a lack of exposure to sunlight in urban areas. But in general, most people get their vitamin D from a combination of all three sources, unless you enjoy sitting by a window with your palms up for 20 minutes a day.
