The present invention provides methods for manipulating epigenetic factors to treat pediatric or juvenile osteoporosis. Specifically, the present invention provides methods for the application of H3K27 demethylase inhibitors in pediatric or juvenile subjects with osteoporosis. Thus, the present invention provides methods of administration of the H3K27 demethylase inhibitor, GSK-J4, to pediatric or juvenile subjects to effectively inhibit primary and secondary pediatric osteoporosis, especially for long-term glucocorticoid treated patients (juvenile rheumatoid disorders, Crohn's disease, nephrotic syndrome, and Duchenne muscular dystrophy) and patients who have compromised mobility (cerebral palsy, Rett syndrome, Duchenne muscular dystrophy, spina bifida, and spinal muscular atrophy).