Vitamin D and Calcium Absorption: Toward a New Model

2013 ◽  
pp. 261-272
Author(s):  
Robert P. Heaney
Keyword(s):  
Vitamin D ◽  
Calcium Absorption ◽  
New Model

OCCULT MALABSORPTION CAUSING OSTEITIS FIBROSA CYSTICA

1962 ◽  
Vol 40 (4) ◽  
pp. 481-492
Author(s):  
J. G. Devlin ◽  
D. K. O'Donovan
Keyword(s):  
Vitamin D ◽  
Iron Absorption ◽  
Calcium Absorption ◽  
Calcium Balance ◽  
Gluten Free ◽  
Osteitis Fibrosa Cystica ◽  
Mucosal Atrophy ◽  
Cystic Changes ◽  
Calcium Malabsorption ◽  
Radiological Examinations

ABSTRACT A case is reported of intermittent hypercalcaemia, hypophosphataemia and severe skeletal rarefaction with cystic changes. An occult calcium malabsorption was found. Fat, triolein and iron absorption and radiological examinations were normal. There was gross intestinal mucosal atrophy. She was shown to be in a state of negative calcium balance and this was reversed by vitamin D. A gluten-free diet also improved calcium absorption. It is postulated that the patient had severe secondary hyperparathyroidism as the skeleton reverted to normal after six months of medical treatment.

Calcium absorption and vitamin D in the chick

1951 ◽  
Vol 34 (1) ◽  
pp. 105-111 ◽  
Author(s):  
B.B. Migicovsky ◽  
A.M. Nielson
Keyword(s):  
Vitamin D ◽  
Calcium Absorption

The Temporal Distribution of the 1α,25-Dihydroxycholecalciferol Receptor in the Rat Jejunal Villus

1984 ◽  
Vol 67 (3) ◽  
pp. 285-290 ◽  
Author(s):  
S. D. H. Chan ◽  
D. Atkins
Keyword(s):  
Vitamin D ◽  
Vitamin D Deficiency ◽  
Calcium Absorption ◽  
Sedimentation Coefficient ◽  
Temporal Distribution ◽  
High Affinity ◽  
High Affinity Receptor ◽  
Affinity Receptor ◽  
Cell Fractions ◽  
Crypt Cells

1. The distribution of the 1α,25-dihydroxycholecalciferol receptor was studied in enterocytes isolated from the upper, mid and lower villus and crypt cells of the jejunum of normal and rachitic rats. 2. In all cell fractions a high-affinity receptor (KD ⋍ 0.07 nmol/l) with a sedimentation coefficient of 3.5S was demonstrated. 3. In normal rats there was a 60% reduction in receptor numbers in crypt cells compared with the mid and upper villous cells. 4. Vitamin D deficiency led to a reduction in receptor numbers in all cell fractions (45% upper villus, 78% crypt cells). 5. The data are compatible with the concept of calcium absorption occurring in the differentiated villous cells and also account for the reduction in absorption in rachitic animals.

SEVERE IDIOPATHIC HYPERCALCEMIA OF INFANCY

PEDIATRICS ◽  
1957 ◽  
Vol 19 (3) ◽  
pp. 362-371
Author(s):  
George L. Daeschner ◽  
C. William Daeschner
Keyword(s):  
Vitamin D ◽  
Renal Function ◽  
Impaired Renal Function ◽  
Calcium Absorption ◽  
Severe Form ◽  
Additional Case ◽  
Mild Form ◽  
Laboratory Findings ◽  
Pathologic Features ◽  
Motor Retardation

A syndrome occurring in infants and characterized clinically by anorexia, vomiting, constipation, hypotonia, hypertension, characteristic facies, and severe mental-motor retardation, and by the laboratory findings of hypercalcemia, azotemia and impaired renal function has recently been described by British and Swiss workers. The disease apparently occurs in two forms, referred to as mild and severe. The literature concerning the severe form has been reviewed and an additional case reported. Hypersensitivity to vitamin D with excessive calcium absorption has been demonstrated in the mild form of this syndrome and has also been proposed as the metabolic abnormality responsible for the pathologic features of the severe form of the disease.

scholarly journals Effects of Age and Serum 25-OH-Vitamin D on Serum Parathyroid Hormone Levels

2012 ◽  
Vol 97 (11) ◽  
pp. 3989-3995 ◽  
Author(s):  
A. Valcour ◽  
F. Blocki ◽  
D. M. Hawkins ◽  
Sudhaker D. Rao
Keyword(s):  
Vitamin D ◽  
Calcium Absorption ◽  
Small Sample Size ◽  
International Workshop ◽  
Large Population ◽  
Small Sample ◽  
Reference Laboratory ◽  
Population Database ◽  
Age Related ◽  
Serum Pth

Context: Several studies define optimal serum 25-hydroxyvitamin D (25-OHD) levels based on serum PTH level reaching an asymptote. However, results differ widely, ranging from 25-OHD levels of 12–44 ng/ml: many studies are constrained by small sample size. Objective: The objective of the study was to determine the relationship between serum PTH and 25-OHD levels and age in a very large reference laboratory database. Design: This was a detailed cross-sectional analysis of 312,962 paired serum PTH and 25-OHD levels measured from July 2010 to June 2011. Results: Median PTH levels and the proportion of patients (PTH > 65 pg/ml), from 63 successive 25-OHD frequency classes of 5000 patients, provide smooth, exceptionally well-fitted curves (R2 = 0.994 and R2 = 0.995, respectively) without discernible inflection points or asymptotes but with striking age dependencies. Serum 25-OHD was below the recent Institute of Medicine sufficiency guidance of 20 ng/ml in 27% (85,000) of the subjects. More importantly, 40 and 51% of subjects (serum 25-OHD <20 and 10 ng/ml, respectively) had biochemical hyperparathyroidism (PTH > 65 pg/ml). Conclusions: This analysis, despite inevitable inherent limitations, introduces several clinical implications. First, median 25-OHD-dependent PTH levels revealed no threshold above which increasing 25-OHD fails to further suppress PTH. Second, the large number of subjects with 25-OHD deficiency and hyperparathyroidism reinforces the Third International Workshop on Asymptomatic Primary Hyper parathyroidism's recommendations to test for, and replete, vitamin D depletion before considering parathyroidectomy. Third, strong age dependency of the PTH-25-OHD relationship likely reflects the composite effects of age-related decline in calcium absorption and renal function. Finally, this unselected large population database study could guide clinical management of patients based on an age-dependent, PTH-25-OHD continuum.

Regulation of calcium absorption by 1,25,dihydroxy-vitamin D—Studies of the effects of a bisphosphonate treatment

1982 ◽  
Vol 34 (1) ◽  
pp. 317-320 ◽  
Author(s):  
S. Adami ◽  
W. B. Frijlink ◽  
O. L. M. Bijvoet ◽  
J. L. H. O'Riordan ◽  
T. L. Clemens ◽  
...  
Keyword(s):  
Vitamin D ◽  
Calcium Absorption ◽  
Bisphosphonate Treatment
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