Osteomalacia clinical features

Primary hyperparathyroidism occurs as a result of hyperplasia or the occurrence of adenoma. Secondary hyperparathyroidism may result from renal failure because of the associated phosphate retention, resistance to the metabolic actions of PTH, or impaired vitamin D metabolism. The last-mentioned factor is primarily responsible for the development of osteomalacia. Muscle symptoms are much more common in patients with osteomalacia than in primary hyperparathyroidism. Muscle biopsy has revealed disseminated atrophy, sometimes confined to type 2 fibers, but in other cases involving both fiber types. Clinical features of osteomalacic myopathy are proximal limb weakness and associated bone pain the condition responds well to treatment with vitamin D. 

Vitamin D deficiency remains the most common cause of rickets and osteomalacia in the world, with the exception of the United States and the Scandinavian countries where most dairy products are supplemented with this vitamin. This deficiency can be caused either by dietary habits or by insufficient exposure to ultraviolet light. The same type of symptoms can be observed when there is interruption of the normal vitamin D metabolic pathways due to a number of liver and/or kidney diseases. In addition, a number of inherited factors can lead to different types of vitamin D resistance which require massive supplements of vitamin D and/or minerals. Extensive reviews have been published depicting both the clinical features and their most likely causes, as well as the possible treatments of the different types of clinical disorders resulting from vitamin D deficiencies [113-117], The newly defined role for l,25(OH)2D3 upon the hematopoietic system could also have clinical relevance in bone disorders such as osteoporosis where patients have been shown to possess abnormal T-cell subsets [118]. 

Table 2 Characteristic clinical features and blood serum measurements in rickets and osteomalacia...

The primary cause of rickets and osteomalacia is vitamin D deficiency and the clinical characteristics of these diseases depend on age at onset. The biochemical patterns of too low a serum concentration of 25(0H)D3, however, remain quite similar (Table 2) even though the structural effects on the skeleton differ. One common microscopic feature of the skeleton is that both rickets and osteomalacia... 

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