Osteomalacia and Vitamin D Status: A Clinical Update 2020

Abstract

Historically, rickets and osteomalacia have been synonymous with vitamin D deficiency dating back to the 17th century. The term osteomalacia, which literally means soft bone, was traditionally applied to characteristic radiologically or histologically documented skeletal disease and not just to clinical or biochemical abnormalities. Osteomalacia results from impaired mineralization of bone that can manifest in several types, which differ from one another by the relationships of osteoid (ie, unmineralized bone matrix) thickness both with osteoid surface and mineral apposition rate. Osteomalacia related to vitamin D deficiency evolves in three stages. The initial stage is characterized by normal serum levels of calcium and phosphate and elevated alkaline phosphatase, PTH, and 1,25-dihydroxyvitamin D [1,25(OH) 2 D]-the latter a consequence of increased PTH. In the second stage, serum calcium and often phosphate levels usually decline, and both serum PTH and alkaline phosphatase values increase further. However, serum 1,25 (OH) 2 D returns to normal or low values depending on the concentration of its substrate, 25-hydroxyvitamin D (25OHD; the best available index of vitamin D nutrition) and the degree of PTH elevation. In the final stage, hypocalcemia and hypophosphatemia are invariably low with further exacerbation of secondary hyperparathyroidism. The exact,or even an approximate, prevalence of osteomalacia caused by vitamin D deficiency is difficult to estimate, most likely it is underrecognized or misdiagnosed as osteoporosis. Signs and symptoms include diffuse bone, muscle weakness, and characteristic fracture pattern, often referred to as pseudofractures, involving ribs, scapulae, pubic rami, proximal femurs, and codfish-type vertebrae. The goal of therapy of vitamin D-deficiency osteomalacia is to alleviate symptoms, promote fracture healing, restore bone strength, and improve quality of life while correcting biochemical abnormalities. There is a need for better understanding of the epidemiology of osteomalacia. Simplified tools validated by concurrent bone histology should be developed to help clinicians promptly diagnose osteomalacia.

Genetics and Epigenetics of Bone Remodeling and Metabolic Bone Diseases

“…It is more common in elderly females than elderly males [189]. Osteomalacia is caused by disorders that lead to decreased mineralization of bone [190]. It is associated with poor bone quality causing atraumatic fractures, pseudofractures, delayed fracture healing, and bone pain [191].…”

“…It is associated with poor bone quality causing atraumatic fractures, pseudofractures, delayed fracture healing, and bone pain [191]. This disease is defined by a marked softening of the bones and is commonly caused by a lack of vitamin D [190]. Perhaps the rarest cause of osteomalacia is that caused by a neoplasm, so-called tumor-induced osteomalacia (TIO) [192].…”

Das Knochenmarködemsyndrom

“…Es gibt verschiedene Formen der Osteomalazie, wobei die Vitamin-D-Mangel-bedingte die mit Abstand häufigste Form darstellt [22]. Eine Vitamin-D-Insuffizienz ist definiert als ein 25-OH-D-Serumspiegel von unter 30 ng/ml und stellt in Deutschland ein endemisches Problem dar [23].…”

A Case of Femoral Neck Insufficiency Fracture due to Tumor-Induced Osteomalacia

“…Complete resection of the tumor can lead to rapid improvement and resolution of all symptoms. However, if the tumor remains unresected or partially resected, persistent osteomalacia could lead to delayed fracture unions due to disordered bone calcification [ 4 ]. Herein, we report a case of insufficiency fracture of the left femoral neck due to TIO resulting from a partially resected tumor.…”