Osteomalacia prevalence

The nutritional experiments with carotene and fish oils led to the conclusion that a second fat-soluble compound was essential for normal rat growth. Rickets, the condition caused by vitamin D deficiency, is a disease afflicting children where, because of impaired calcification, bone formation is disturbed and the bones become bowed and otherwise deformed. In adults, especially multiparous women, vitamin D deficiency produced osteomalacia—demineralization of bone, leading to tenderness over the bones, pain, and muscle weakness. Rickets was particularly prevalent in slum areas. Glasgow, Vienna, and Lahore were notorious for the high incidence of the disease. 

Osteoporosis, a condition in which bone becomes porous and weak (potentially leading to fractures), is a far more prevalent disease than osteomalacia. While modest levels of serum 25-hydroxyvitamin D will prevent osteomalacia, these levels may not be sufficient to minimize the risk of osteoporosis. Clinical studies have demonstrated that bone mineral density is directly related to serum 25-hydroxyvitamin D levels up to 40 ng/ml. It has also been demonstrated that in elderly women given unusually high doses of calcium and vitamin D3 the risk of both hip and vertebral fractures is substantially reduced. Optimizing bone health in both young and old may require higher levels of vitamin D activity than are typically achieved at recommended doses. This story will play out over time. 

The term hepatic osteopathy (J.E. Compston, 1986) describes skeletal changes in chronic liver diseases, including osteoporosis, which is by far the most prevalent form, and osteomalacia, which is detected very rarely, as well as their respective mixed forms. 

Metabolic bone diseases result from a partial uncoupling or imbalance between bone resorption and formation. Decreased bone mass, or osteopenia, is more common than abnormal increases of bone mass. The most prevalent metabolic bone diseases are osteoporosis, osteomalacia and rickets, and renal osteodystrophy. Osteoporosis, the most prevalent metabolic bone disease in developed countries, is characterized by loss of bone mass, microarchitectural deterioration of bone tissue, and increased risk of fracture. Rickets and osteomalacia, which are more common in the less-developed countries, are characterized by defective mineralization of bone matrix. Renal osteodystrophy is a complex condition that develops in response to abnormalities of the endocrine and excretory functions of the kidneys. These three metabolic bone diseases and Paget s disease, a localized bone disease, are discussed below followed by laboratory markers of bone metabolism. 

The prevalence of postgastrectomy osteomalacia (M20) depends largely on definition. Minor histological abnormalities are demonstrable in at least 12% of gastrectomized patients clinical cases are relatively rare (E5, G5). Serum alkaline phosphatase activities in patients with severe forms of this disorder may be as high as 5 times the upper reference limit, whereas in patients with milder forms, the values are usually normal (G5). 

The prevalence of skeletal disease among patients with nonterminal renal failure is not known. The majority of such patients do not complain of skeletal symptoms and their serum alkaline phosphatase activities are not markedly elevated. The mean for all patients in one study (15) was 1.5 times the upper reference limit for adults. In some patients with nonterminal renal failure, systemic acidosis is out of proportion to the degree of nitrogenous retention, and it currently seems that acidotic patients are more liable to develop skeletal abnormalities. Mean serum alkaline phosphatase in a group of such patients was 3.5 times the upper reference limit, with individual values of almost 10 times the upper reference limit (15). The rise in total serum alkaline phosphatase, which is largely due to increases in the bone isoenzyme (15, P15), shows a significant positive correlation with the severity of parathyroid osteopathy, irrespective of the presence or absence of concurrent osteomalacia (P15). 

In order to test this hypothesis it was necessary to compare populations with differing dietary practices but with similar exposure to environmental lead. The "Asian immigrant population in Britain, which is in fact derived from India and Pakistan, is known to differ in nutritional and cultural practices in comparison with the indigenous community. It is characterised by the prevalence of disorders of mineral metabolism including osteomalacia, and in the young, nutritional rickets and neonatal hypocalcaemia. A study was therefore undertaken in two towns located near London - Luton and Bedford - in which there are mutiracial populations (Strehlow and Barltrop 1978). Children from the Asian and non-Asian community aged 2-5 years were selected at random from computer-based local authority records and venous blood samples obtained for analysis. 

The disease itai-itai became prevalent in Japan prior to and during the 1940s, and was associated with the ingestion of cadmium-contaminated rice. The rice became contaminated after growing in waste runoff water from a lead-zinc-cadmium mine. Clinical manifestations of the disease included kidney injury, osteomalacia, myalgia, and spontaneous fracture of long bones (Tsuchiya 1978). 

The importance of vitamin D—the sunshine vitamin—in human nutrition lies in the role of regulating calcium and phosphorus metabolism. Vitamin D promotes intestinal absorption of calcium and phosphorus and influences the process of bone mineralization. In the absence of vitamin D, mineralization of bone matrix is impaired, resulting in rickets in children and osteomalacia in adults. Although rickets is rare in the United States, it is still prevalent in many countries. 

The last few years have witnessed a resurgence of rickets and osteomalacia in the US and possibly in other technologically advanced nations. The prevalence of rickets in the US has occurred primarily among young children of color, i.e., African-Americans and Hispanics, after cessation of breastfeeding and the failure to provide adequate amounts of vitamin D-fortified milk. The prevalence of... 

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