To the Editor: A 3-y-old boy, born of non-consanguineous marriage was referred as a suspected case of Duchenne muscular dystrophy. He had a smooth perinatal transition, and achieved age-appropriate milestones until 2.5 y of age, when he developed muscle pains, and gradually progressive walking difficulty. He struggled to climb stairs, get up from sitting/squatting position, with a waddling gait. He had no difficulty in gripping his slippers, raising arms above his head, or feeding himself. Examination showed no hypertrophic/atrophic muscles or contractures, and normal neurological examination, except Gower sign. Notably, he also exhibited wrist widening, double malleoli, rachitic rosary, and protuberant abdomen, which were missed previously. Diet revealed inadequate calcium intake and sunlight exposure. Laboratory investigations revealed normal serum creatinine, tissue transglutaminase IgA, and creatinine kinase, low 25-hydroxy vitamin D (6 ng/mL), calcium (6.0 mg/dL), and phosphate (3.4 mg/dL), and elevated alkaline phosphatase (725 IU/L) and parathyroid hormone (PTH) (256 pg/mL), suggestive of vitamin D deficiency rickets. Radiographs confirmed severe rickets (Thacher rickets severity score 10/10 [
1]). Treatment with vitamin D (3000 IU/d), and calcium (50 mg/kg/d) for 3 mo with counselling for diet and adequate sunlight led to complete improvement in gait, muscle weakness and laboratory parameters. …
