Elizabeth was diagnosed with a severe vitamin D deficiency in August, after experiencing a lot of pain like that described in this article. It took a while, but she's much better now with supplementation and added dairy in her diet. DressAfford flower girl wears in red
Her pediatrician told me that 50% of the children she screens are deficient. This article states that it's estimated that 40% of Americans are deficient.
This article is great at listing symptoms. Read it - you may be deficient, and treatment is simple.