Not to be the correlation/causation asshole, but I wonder if possibly low vitamin D is to some extent a proxy for being a low income sedentary shut-in, all things that on their own are tied to disease.
As the article points out Vitamin D supplementation is not very effective vice working up a tan a couple times a year. So in modern America we can surmise the individual with low vitamin D levels is someone who sits inside watching TV all year. And can't afford a winter vacation to somewhere sunny.
Is the problem low vitamin D, or is it being sedentary inside all year? It's probably actually the vitamin D.
As the article points out Vitamin D supplementation is not very effective vice working up a tan a couple times a year. So in modern America we can surmise the individual with low vitamin D levels is someone who sits inside watching TV all year. And can't afford a winter vacation to somewhere sunny.
Is the problem low vitamin D, or is it being sedentary inside all year? It's probably actually the vitamin D.