The work presented here is funded by a UK Medical Research Council grant (G0701603). The UK Medical Research Council, the Wellcome Trust and the University of Bristol provide core support for ALSPAC. Salary support for AS is provided by Wellcome

Trust grant ref. 079960, which also funded the pQCT scans. DAL works in a centre that receives core funds from the UK Medical Research Council (G G0600705) and University of Bristol. No funding body directed the study or interfered with its conduct and interpretation of results; the views presented here are those of the authors and not necessarily any funding body. This publication is the work of the authors who serve as guarantors for the contents of this paper. Conflicts of interest None. Open Access This article is distributed under the Apitolisib terms of the Creative Commons Attribution Noncommercial License which permits any noncommercial use, distribution, and reproduction in any medium, provided the original author(s)

and source are credited. Electronic MK-1775 manufacturer supplementary material Below is the link to the electronic supplementary material. Table S1 Associations between plasma concentration of 25(OH)D2 and pQCT strength parametres (DOC 60.0 kb) Table S2 Associations between plasma concentration of 25(OH)D3 and pQCT strength parametres (DOC 59.0 kb) Table S3 Sensitivity analysis of the Florfenicol associations of plasma concentration of 25(OH)D2 and 25(OH)D3 with buckling ratio (DOC 61.5 kb) References 1. Mosekilde L (2005) Vitamin D and the elderly. Clin Endocrinol (Oxf) 62(3):265–281CrossRef 2. Weaver CM (2007) Vitamin D, calcium homeostasis, and skeleton accretion in children. J Bone Miner Res 22(Suppl 2):V45–V49PubMedCrossRef 3. Sullivan SS, Rosen CJ, Halteman WA, Chen TC, Holick MF

(2005) Adolescent girls in Maine are at risk for vitamin D insufficiency. J Am Dietetic Assoc 105(6):971–974CrossRef 4. Ross AC, Taylor LC, Yaktine AL, Del Valle HB (2010) Committee to review dietary reference intakes for vitamin D and calcium. Institute of Medicine Institute of Medicine 5. Winzenberg TM, Powell S, Shaw KA, Jones G (2010) Vitamin D supplementation for improving bone mineral density in children. Cochrane Database Syst Rev 10:CD006944PubMed 6. El-Hajj Fuleihan G, Nabulsi M, Tamim H et al (2006) Effect of vitamin D replacement on musculoskeletal parameters in school children: a randomized controlled trial. J Clin Endocrinol Metab 91(2):405–412PubMedCrossRef 7. Greene DA, Naughton GA (2010) Calcium and vitamin-D supplementation on bone structural properties in peripubertal female identical twins: a randomised controlled trial. Osteoporos Int. Jun 11 8.