We make Vitamin D in our bodies when we expose our skin to the sun as you can see from the graphic below. The sun needs to be at the proper angle, unfettered by clouds. Folks, not only is this one chariot we can't harness, we also can't change our position on the planet.
This simple fact - the necessity for sun exposure - poses a huge problem for us. For most of the year, because of our northern latitude, the sun's rays fall on us at an angle that is far too low to provide adequate ultraviolet B exposure. The angle is wrong for SEVEN months. As a matter of fact, everyone who lives above the 37th parallel is at risk during the winter months. And we are way north of the 37th parallel. In Juneau, we are at the 58th parallel which is not even on this map below; not only that, the rest of Alaska is way north of the 58th parallel. Take a look at the map below to see which parts of the US have adequate sun during the whole year.
Can you see the scope of our problem? And here is another problem that can't be solved. Even though Juneau is in the southern part of Alaska, it is one of the cloudiest places in the entire country - #6, in fact. So even when the angle of the sun is high enough to allow proper exposure, cloud cover often prevents it for those of us who live in the rain forest. (According to weather research, Juneau is cloudy 88% of the year.)
It was disheartening to discover that Vitamin D deficiency is related to all kinds of diseases: cancers of the breast, colon and prostate; rheumatoid arthritis, multiple sclerosis, heart disease, diabetes, periodontal disease, SAD, and more. The long list takes my breath away. Just by living year round in Alaska, we are at risk. Wow. How can this incredible environment not support human health? A traditional diet did, but few eat that way anymore.
It is a wonder that we are all not falling down, one after the other, from lack of Vitamin D. But I think it happens without our being really aware of it. It happens every time someone is diagnosed with cancer, with MS, with arthritis... According to Seaton's resolution, our state has "a high incidence of preventable diseases that numerous studies indicate may be correlated with insufficient blood serum levels of Vitamin D."
I tell myself I would be bored silly living in a tropical paradise, but at least I wouldn't have to worry about Vitamin D. Until I find myself lolling about on a beach, I need to remember to take my supplements every day!