Why is there an epidemic of vitamin D deficiency?

It is estimated that anywhere from 30 to 100% of Americans, depending upon their age and community living environments, are deficient in Vitamin D. More than half of all American children are vitamin deficient. Supposedly almost 3/4s of pregnant women are vitamin D deficient, predisposing their unborn children to all sorts of problems. Worldwide, it is estimated that the epidemic of vitamin D deficiency affects one billion people.

The fact is that we spend too much time indoors and when we go out into the sun, we lather sunscreen on ourselves. We no longer provide our bodies with the genetically required nutrients and we have a major epidemic on our hands.