Even Sunscreen has Disadvantages

Here's a recent article from AOL News: Study Finds Vitamin D Deficiency in Kids.

A study of 6,000 people, ages 1-21, showed a Vitamin D deficiency in 70% of the nation's children and teens. That's 58.4 million youth. Lack of Vitamin D is associated with bone diseases like rickets and osteoporosis. Long term effects may include type 1 diabetes, cancer, and multiple sclerosis.
The cause is sited as poor diet and lack of sunshine. Fish, shiitake mushrooms, and milk top the list of foods rich in Vitamin D. Personally, those aren't foods that often show up in my own diet. As for sunshine, study leader Dr. Michal L. Melamed said, "Kids have more sedentary lifestyles today and are not spending as much time outdoors. The widespread use of sunscreens, which block UV-B rays, has only compounded the problem." Sunburn is bad for our skin and poses more risk for skin cancer, but not every outdoor occasion requires spf 50+.

Milk (including soymilk), orange juice, infant formula, and some dry foods are fortified with added Vitamin D. However, another article posted on Reuters last year noted that "6 percent of the children fed fortified formula also were vitamin D deficient. The researchers said this raised questions about whether the fortification was sufficient." For me, this raises the question is laboratory fortification as good as the real thing?