It seems our boys are across the board with this, but some boys with DMD do have issues with low vitamin D levels. Boys using steroids are also at risk for developing osteoporosis/brittle bones. Our son has been combating low vitamin D issues for years now. He's had all kinds of lab workup done ( ruled out Celieac Disease, Parathyroid problems, etc.). Inspite of giving him 2,200 iu's of vitamin…