The media discovered the vitamin D deficiency pandemic last week. Amazingly researchers were recorded on camera saying that the D deficiencies are caused by insufficient exposure to ultraviolet in sunlight and inadequate consumption of vitamin D-laced milk. Have all of these people been avoiding the biomedical journals?
It seems that the simplest conclusion is that chronic inflammation leads to vitamin D deficiency, even though vitamin D deficiency may also contribute to inflammation.
This also probably means that chronic inflammation makes it harder for skin to produce vitamin D during exposure to sunlight.