Bone demineralization

D Calciferol Maintenance of calcium balance enhances intestinal absorption of Ca and mobilizes bone mineral Rickets = poor mineralization of bone osteomalacia = bone demineralization... 

Pediatric patients are also at higher risk for IBD-associated bone demineralization, which is accelerated by the use of systemic corticosteroids. 

Women. Studies of women suggest that conditions of pregnancy, lactation, and osteoporosis may intensify bone demineralization, thus mobilizing bone lead into the blood resulting in increased body burdens of lead (Silbergeld et al. 1988). For example, women show an increased rate of bone lead loss with age relative to men (Drasch et al. 1987). Women with postmenopausal osteoporosis may be at an... 

The major manifestation of chronic metabolic acidosis is bone demineralization with the development of rickets in children and osteomalacia and osteopenia in adults. 

Cirrhosis and liver failure may produce bone demineralization. 

Exceeding the 2-wk treatment periods for osteoporosis may lead to bone demineralization and osteomalacia... 

Osteoporosis Generalized bone demineralization often associated with effects of aging and hormonal changes in postmenopausal women Calcium supplements, vitamin D, calcitonin, bisphosphonates, intermittent parathyroid hormone, estrogen, or SERMs (raloxifene] (see Chapter 30]... 

Brief History. R.D. is a 74-year-old woman with a history of generalized bone demineralization caused by osteomalacia that was primarily brought on by poor diet that is, her... 

Despite the logic of ketogenic diets for PDC deficiency on biochemical grounds, there are several theoretical concerns regarding their long-term use. For example, diets in which the fat intake is relatively low (<65%) may contain an amount of protein (to accommodate caloric needs) that exceeds the age-adjusted recommended dietary allowance. The acid load from such diets could exacerbate the congenital acid-base disorder in PDC-defective individuals and could contribute to the renal hyperfiltration reported to occur in some patients. Ketogenic diets may also cause hypercalciuria and increase the risk of bone demineralization in PDC deficiency. 

A2. Antoniazzi, F., Bertoldo, F., Lauriola, S., Sirpresi, S., Gasperi, E., etal., Prevention of bone demineralization by calcium supplementation in precocious puberty during gonadotropin-releasing hormone agonist treatment. J. Clin. Endocrinol. Metab. 84, 1992-1996 (1999). 

Q5 An increase in the secretion of PTH results in development of hyperparathyroidism. This causes hypercalcaemia and bone demineralization. It can promote the following effects on the body ... 

EXCESS results in hypercalcemia calcium may deposit in various tissues or precipitate as renal stones there is bone demineralization. 

Corticosteroids stimulate the conversion of vitamin D to its inactive metabolite and have been shown to cause bone demineralization when used for long period of time. 

Barcia, J. E, Strife, C. R, and Langman, C. (1997). Infantile hypophosphatemia Treatment options to control hyperealcemip, hypcicalciuria, and chronic bone demineralization, /. Pediair 130, 825-828-... 

It is difficult to distinguish between the mean bone loss that occurs in normal pregnancy and the additive effect on bone demineralization that results from heparin therapy further prospective studies on bone demineralization during pregnancy are needed to clarify this point. 

Vitamin D Hypertension Hypercalcemia Metastatic calcification Bone demineralization Renal calcinosis and kidney failure... 

Excess vitamin D results in hypercalcemia and hype-rcalciuria, due to increased calcium absorption, bone demineralization, and hyperphosphatemia. 

Once consumed, dairy products contribute to acidity in multiple ways. They contain acidic saturated fats and acidic concentrated animal protein. And acidity plays a role in bone demineralization and osteoporosis, as you will discover in chapter 3. 

Dumping calcium and other substances from the bones might be a relatively harmless mechanism if it is rarely used, but it is not a sustainable approach to blood pH balance over the long term. Yet because of poor dietary and lifestyle patterns, that is precisely what most people are forcing their bodies to do. Balance may be restored to the blood, but it comes at a high cost weakened bones and a suppressed capacity for additional bone formation. So it is no surprise that the incidence of bone-demineralizing diseases such as osteoporosis are on the rise. (You ll leam more about this tragic disorder in the next chapter.)... 

You may be thinking, I can just eat more dairy products. After all, they build strong bones. That s what conventional medical thought and the various dairy bureaus that market and profit from dairy products would have you believe, but it couldn t be further from the truth. Dairy products are high in concentrated proteins that cause acidity in the body. Scientists link a high-protein diet from meat and dairy products to bone demineralization. Consuming dairy products can cause the body to lose more calcium from the bones than it can take in. 

Chronic metabolic acidosis is usually not associated with severe acidemia and is relatively asymptomatic. The major manifestations are in the bones, where chronic acidemia causes bone demineralization with the development of rickets in children and osteomalacia and osteopenia in adults. In infants and children, chronic metabolic acidosis is associated with growth failure and short stature and may be associated with nonspecific symptoms including anorexia, nausea, weight loss, and muscle weakness. 

The kidney plays a critical role in calcium homeostasis. PTH acts directly on the kidney to suppress calcium ion excretion in the urine by maximizing tubular calcium reabsorption. It increases phosphate ion excretion in the kidney (phosphaturic effect) to prevent excessive accumulation of this anion released during bone demineralization. 

B. Hyperparathyroidism is the likely cause of all of the patient s symptoms. Increased parathyroid hormone leads to bone demineralization, increased calcium uptake from the intestine, increased blood levels of calcium, decreased calcium ion excretion by the kidney, and increased phosphate excretion in the urine. Increased blood calcium levels caused renal stones, while bone demineralization progressed to osteopenia. The patient s intake of calcium and vitamin D are not excessive. Calcitonin acts to decrease bone demineralization. Muscle weakness and depression reflect the widespread role of calcium ion in many physiologic processes. 

C. The major action of vitamin D is to increase absorption of calcium from the small intestine. Deficiency of the vitamin leads to low blood calcium levels, stimulation of parathyroid hormone secretion, and acting synergistically, promotion of bone demineralization. Renal excretion of calcium is decreased by hypocalcemia but elevated parathyroid hormone levels promote renal excretion of phosphate, to prevent excessive accumulation of this product of bone demineralization. Although lack of exercise decreases bone density, it does not lead to rickets if vitamin D is sufficient. 

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