Sub-optimal vitamin D status in children and youth with diseases associated with low bone mass : konference: IOF World Congress on Osteoporosis, Toronto, Kanada, 2.6.-6.6.2006 [abstrakt] - Atkinson, S. A; Docherty-Skippen, S; Wang, D; Grey, V; Barr, R; Ronen, G; Odame, I (Pohybové ústrojí. Pokroky ve výzkumu, diagnostice a terapii, 2006)