Symptoms common to osteomalacia and rickets
Clinical features that are common to osteomalacia and rickets
Osteomalacia and rickets cause pain and deformity in the long bones and pelvis. Laboratory features of those with osteomalacia due to vitamin D deficiency include low or low-normal serum calcium and phosphate levels, low 25-OH vitamin D levels, elevated serum alkaline phosphatase, elevated PTH levels, and low 24-hour urinary calcium excretion. Laboratory features of those with osteomalacia due to renal phosphate wasting (familial hypophosphatemic rickets/adult-onset vitamin D-resistant osteomalacia and oncogenic osteomalacia) include low serum phosphate, high serum alkaline phosphatase, high urinary phosphate (low tubular reabsorption of phosphate), and inappropriately normal or low 1,25 (OH) 2 vitamin D for the degree of hypophosphatemia. Radiographs in adults may show characteristic pseudofractures (milkman’s fractures, Looser’s zones) where large arteries cross bones or in children may show changes of rickets (see Question 26). Bone biopsies show increased osteoid seams but with reduced hydroxyapatite deposition.