Low 1,25-Dihydroxyvitamin D, Secondary Hyperparathyroidism, and Normal Osteocalcinin Elderly Subjects

Abstract

The relationship among serum vitamin D metabolites, PTH, and osteocalcin concentrations was investigated in 20 elderly subjects. All except 2 had subnormal 25-hydroxyvitamin D concentrations. Eighteen (90%) had subnormal serum 1,25-dihydroxyvitamin D [1,25-(OH)2D] concentrations, while 8 subjects (40%) had elevated PTH concentrations. There was a highly significant inverse relationship between PTH and 1,25-(OH)2D concentrations. Serum osteocalcin concentrations were not elevated in any subject, and in fact, the mean osteocalcin concentration was in the lower part of the normal range. These data indicate no compensatory increase in 1,25-(OH)2D in response to secondary hyperparathyroidism and no increase in osteocalcin in response to hypersecretion of PTH in the elderly. These 2 defects may contribute to the bone disease of the elderly.

Bone Density, Bone Turnover, and Hormone Levels in Men Over Age 75

“…It has been postulated that the decreased calcium absorption and resultant increase in parathyroid hormone (PTH) secretion causes increased bone loss in older individuals (2). Several cross-sectional studies have detected increasing PTH with age (3)(4)(5), and increased bone mineral density (BMD) has been seen in individuals with hypoparathyroidism (6). Testosterone is important in development of peak bone mass but plays an uncertain role in age-related bone loss (7).…”

Severe Myopathy Associated With Vitamin D Deficiency in Western New York

“…These subjects may also be unable to increase osteocalcin, important for adequate bone formation. 16 Although parathyroid hormone concentrations decreased, they did not normalize despite several months of vitamin D therapy and the normalization of serum 25-hydroxyvitamin D. This has previously been described in patients with long-standing vitamin D deficiency. 4 The nonnormalization of parathyroid hormone concentrations despite normalization of 25-hydroxyvitamin D suggests a degree of autonomy of the parathyroid glands due to long-standing vitamin D deficiency.…”

Radiological spectrum of endemic fluorosis: relationship with calcium intake

“…Alternatively, the formation of fluorapatite salts in the bone leading to partial resistance to parathyroid hormone could be the explanation [14]. Another factor could be coexistent calcium or vitamin D deficiency [4].…”