Excessive Sun Protection Measures Leading to Vitamin D Deficiency

I often find myself wondering about the health effects of excessive sun protection measures. The type you see in Japan, where somebody has their entire skin surface completely covered. So, today, I did a little bit of research on it. And I am not surprised to see that there have been studies (including this 2024 Osaka Metropolitan University one) that indicate that sun avoidance behavior in Japan is contributing to vitamin D deficiency, particularly in young Japanese women.

To be honest, I am not surprised, because I often see Japanese women who literally cover themselves from head to toe to avoid sunrays - all year round, not just in summer. With arm covers that even conceal the hands, full length trousers and wide hats. I'm sure you've seen the hats with a full-face mask attached, leaving only the eyes exposed. I often see people wear sunglasses over the eyes too, so literally not one inch of their body is exposed to the sun. 

In my home country it is commonly believed that people of all ages should let the sun on their skin for at least 20 minutes a day. For children, they recommend with sunscreen. But for adults, recently some doctors even recommend 20 minutes in the sun without sunscreen. Not to sunbathe, but to sit on the patio with a book or take a walk or gardening or chatting with your neighbor over the fence! As it remains the most natural and efficient way our bodies obtain vitamin D.