Calcium Absorption and Plasma 25-Hydroxy-Vitamin D in Elderly Women after Oral 25-Hydroxy-Vitamin D3

1980 ◽  
Vol 59 (3) ◽  
pp. 14P-14P ◽  
Author(s):  
R. M. Francis ◽  
M. Peacock ◽  
J. H. Storer ◽  
B. E. C. Nordin
Keyword(s):  
Vitamin D ◽  
Vitamin D3 ◽  
Calcium Absorption ◽  
Elderly Women ◽  
25 Hydroxy Vitamin D

The Effect of 25-Hydroxy Vitamin D3 in the Osteomalacia of Chronic Renal Failure

1977 ◽  
Vol 52 (5) ◽  
pp. 499-508 ◽  
Author(s):  
J. B. Eastwood ◽  
T. C. B. Stamp ◽  
H. E. De Wardener ◽  
P. J. Bordier ◽  
C. D. Arnaud
Keyword(s):  
Vitamin D ◽  
Renal Failure ◽  
Chronic Renal Failure ◽  
Plasma Concentration ◽  
Muscle Strength ◽  
Vitamin D3 ◽  
Calcium Absorption ◽  
Bone Mineralization ◽  
25 Hydroxy Vitamin D ◽  
Substantial Rise

1. Five patients with the osteomalacia of chronic renal failure were given 50–100 nmol of 25-hydroxy vitamin D3 intravenously per day for 24–28 days. 2. In all five patients, during administration of 25-hydroxy vitamin D3 there was a substantial rise in the plasma concentration of 25-hydroxy vitamin D from initially abnormally low values. 3. Significant improvement in bone mineralization, intestinal calcium absorption and muscle strength occurred in the three patients with the greatest rise in plasma 25-hydroxy vitamin D.

In Vitro Cellular Muscle Calcium Metabolism. Characterization of Effects of 1,25-Dihydroxy-Vitamin D3 and 25-Hydroxy-Vitamin D3

1985 ◽  
Vol 40 (1-2) ◽  
pp. 102-108 ◽  
Author(s):  
Ana R. de Boland ◽  
Ricardo Boland
Keyword(s):  
Vitamin D ◽  
Vitamin D3 ◽  
Plasma Membranes ◽  
Selective Inhibition ◽  
Ruthenium Red ◽  
Ca Uptake ◽  
25 Hydroxy Vitamin D ◽  
Muscle Calcium

Cultures of vitamin D-deficient chick soleus muscle and 12 day-old chick embryo myoblasts were used to characterize the effects of 1,25-dihydroxy-vitamin D3 and 25-hydroxy-vitamin D3 on muscle cell Ca metabolism. Physiological amounts of both sterols increased the rate and extent of 45Ca uptake by cultures. However. 1.25(OH)2D3 was significantly more effective than 25 OHD3. The greater potency of 1,25(OH)2D3 to increase Ca uptake could be shown after various treatment intervals of cultures and using a wide concentration range of both derivatives. Information about Ca pools affected by vitamin D3 metabolites was obtained through kinetic analysis of Ca efflux in cultured myoblasts. Cytoplasmic and mitochondria Ca pools were identified on the basis of their half-times of desaturation and by selective inhibition of plasma membrane and mitochondrial Ca transport with LaCl3 and Ruthenium Red, respectively. The data suggests that 1,25(OH)2D3 acts on muscle cellular Ca by increasing Ca efflux and influx through mitochondrial and plasma membranes whereas the predominant effect of 25 OHD3 is to increase Ca influx into mitochondria.

scholarly journals Suboptimal Serum 25-Hydroxy-Vitamin D Is Associated with a History of Recent Disease Exacerbation in Pediatric Patients with Bronchial Asthma or Asthma-Suggestive Recurrent Wheezing

2020 ◽  
Vol 17 (18) ◽  
pp. 6545
Author(s):  
Teodora-Irina Adam-Bonci ◽  
Paraschiva Cherecheș-Panța ◽  
Eduard-Alexandru Bonci ◽  
Sorin Claudiu Man ◽  
Ancuța Cutaș-Benedec ◽  
...  
Keyword(s):  
Vitamin D ◽  
Vitamin D3 ◽  
Pediatric Asthma ◽  
Asthma Severity ◽  
Cross Sectional Study ◽  
Disease Exacerbation ◽  
Recurrent Wheezing ◽  
Cross Sectional ◽  
25 Hydroxy Vitamin D ◽  
History Of

Even though vitamin D is widely acknowledged as having a potential immunomodulatory role in asthma, its exact beneficial mechanisms are yet to be clarified. An optimal serum 25-hydroxy-vitamin D (25-OH-VitD) level in pediatric asthma patients might not rely solely on the effect of dose-dependent vitamin D3 intake, but might also be influenced by factors related to insufficient asthma control. We aimed to survey the prevalence of serum 25-OH-VitD deficiency and analyze whether suboptimal levels were associated with asthma severity factors. The current cross-sectional study enrolled 131 pediatric asthma or asthma-suggestive recurrent wheezing patients, for whom serum 25-OH-VitD, IgE, and eosinophil count were assessed. The prevalence of suboptimal serum 25-OH-VitD was 58.8%. A suboptimal vitamin D status was associated with asthma exacerbation in the previous month (p = 0.02). Even under seasonal oral vitamin D3 supplementation, patients with a positive history of asthma attack in the previous four weeks presented significantly lower serum 25-OH-VitD concentrations, compared to their peers with no disease exacerbation. In conclusion, sequential measurements of serum 25-OH-VitD might prove useful for future studies evaluating the dynamic changes in vitamin D3 status in regard to asthma, especially in symptomatic patients.

scholarly journals Dietary Intake of Vitamin D from Dairy Products Reduces the Risk of Osteoporosis

Nutrients ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1743 ◽  
Author(s):  
Valeria Polzonetti ◽  
Stefania Pucciarelli ◽  
Silvia Vincenzetti ◽  
Paolo Polidori
Keyword(s):  
Vitamin D ◽  
Older People ◽  
Dietary Intake ◽  
Vitamin D3 ◽  
Calcium Absorption ◽  
Daily Intake ◽  
Winter Season ◽  
The United States ◽  
Ultraviolet B ◽  
Dietary Vitamin

Background: Vitamin D and calcium are important dietary compounds that affect bone mass, even if other minerals (potassium, zinc, etc.) and vitamins (A, C and K) are also involved. Vitamin D and certain minerals, in fact, play an important role in calcium homeostasis and calcium absorption. Hip fracture incidence is higher in Europe and the United States, where calcium is frequently included in the human diet; while the occurrence of these fractures is lower in developing countries, where diets are often poor in calcium. This condition is named the “calcium paradox”, and may be partially explained by phosphate toxicity, which can negatively affect mineral metabolism. It is important to maintain correct dietary calcium-phosphate balance in order to have a healthy life, reducing the risk of osteoporotic fractures in older people. Vitamin D can also act as a hormone; vitamin D2 (ergocalciferol) is derived from the UV-B radiation of ergosterol, the natural vitamin D precursor detected in plants, fungi, and invertebrates. Vitamin D3 (cholecalciferol) is synthesized by sunlight exposure from 7-dehydrocholesterol, a precursor of cholesterol that can also act as provitamin D3. Dietary intake of vitamin D3 is essential when the skin is exposed for short periods to ultraviolet B light (UV-B), a category of invisible light rays such as UV-A and UV-C. This can be considered the usual situation in northern latitudes during the winter season, or the typical lifestyle for older people and/or for people with very white delicate skin. The actual recommended daily intake of dietary vitamin D is strictly correlated with age, ranging from 5 μg for infants, children, teenagers, and adults—including pregnant and lactating women—to 15 μg for people over 65 years.

Calcium absorption and intestinal calcium-binding protein: quantitative relationship.

1979 ◽  
Vol 236 (5) ◽  
pp. E556 ◽  
Author(s):  
J J Feher ◽  
R H Wasserman
Keyword(s):  
Vitamin D ◽  
Vitamin D3 ◽  
Calcium Binding ◽  
Calcium Absorption ◽  
Binding Protein ◽  
Quantitative Relationship ◽  
Calcium Binding Protein ◽  
Vitamin D Status ◽  
Loop Technique

The concentration of the vitamin D-induced calcium-binding protein (CaBP) and calcium absorption from the duodenum were investigated in chicks with an in vivo ligated-loop technique. The relation between CaBP and calcium absorption was dependent on a) source of vitamin D activity (either vitamin D3 or 1,25-dihydroxycholecalciferol); b) dosage of vitamin D3; c) time after administration of vitamin D3 to rachitic animals. To aid in the interpretation of these results, a phenomenological model was developed in which CaBP was viewed as being linearly related to a portion of calcium absorption. The model, when applied to the data, suggests that there is a "nonfunctional" pool of CaBP the size of which is determined by the vitamin D status of the animal. After correction for this nonfunctional pool, the proportionality between CaBP and calcium absorption is independent of the vitamin D status of the animal.

scholarly journals Novel vitamin D analogs that modulate leukemic cell growth and differentiation with little effect on either intestinal calcium absorption or bone mobilization

Blood ◽  
1989 ◽  
Vol 74 (1) ◽  
pp. 82-93 ◽  
Author(s):  
JY Zhou ◽  
AW Norman ◽  
M Lubbert ◽  
ED Collins ◽  
MR Uskokovic ◽  
...  
Keyword(s):  
Vitamin D ◽  
Mechanism Of Action ◽  
Vitamin D3 ◽  
Clonal Growth ◽  
Calcium Absorption ◽  
Active Form ◽  
Intestinal Calcium Absorption ◽  
Leukemic Cells ◽  
Binding Studies ◽  
Vitamin D Analogs

Abstract Induction of terminal differentiation of leukemic and preleukemic cells is a therapeutic approach to leukemia and preleukemia. The 1 alpha, 25- dihydroxyvitamin D3 [1,25(OH)2D3], the hormonally active form of vitamin D3, can induce differentiation and inhibit proliferation of leukemia cells, but concentrations required to achieve these effects cause life-threatening hypercalcemia. Seven new analogs of 1,25(OH)2D3 were discovered to be either equivalent or more potent than 1,25(OH)2D3 as assessed by: (a) inhibition of clonal proliferation of HL-60, EM-2, U937, and patients' myeloid leukemic cells: and (b) induction of differentiation of HL-60 promyelocytes. Furthermore, these analogs stimulated clonal growth of normal human myeloid stem cells. The most potent analog, 1,25-dihydroxy-16ene-23yne-vitamin D3, was about fourfold more potent than 1,25(OH)2D3. This analog decreased clonal growth and expression of c-myc oncogene in HL-60 cells by 50% within ten hours of exposure. Effects on calcium metabolism of these novel analogs in vivo was assessed by intestinal calcium absorption (ICA) and bone calcium mobilization (BCM). Each of the analogs mediated markedly less (10 to 200-fold) ICA and BCM as compared with 1,25(OH)2D3. To gain insight into the possible mechanism of action of these new analogs, receptor binding studies were done with 1,25(OH)2–16ene-23yne-D3 and showed that it competed only about 60% as effectively as 1,25(OH)2D3 for 1,25(OH)2D3 receptors present in HL-60 cells and 98% as effective as 1,25(OH)2D3 for receptors present in chick intestinal cells. In summary, we have discovered seven novel vitamin D analogs that are more potent than the physiologic 1,25(OH)2D3 as measured by a variety of hematopoietic assays. In contrast, these compounds appear to have the potential to be markedly less toxic (induction of hypercalcemia). These novel vitamin D compounds may be superior to 1,25(OH)2D3 in a number of clinical situations including leukemia/preleukemia; they will provide a tool to dissect the mechanism of action of vitamin D seco-steroids in promoting cellular differentiation.

Calcium Malabsorption in Elderly Women with Vertebral Fractures: Evidence for Resistance to the Action of Vitamin D Metabolites on the Bowel

1984 ◽  
Vol 66 (1) ◽  
pp. 103-107 ◽  
Author(s):  
R. M. Francis ◽  
M. Peacock ◽  
G. A. Taylor ◽  
J. H. Storer ◽  
B. E. C. Nordin
Keyword(s):  
Vitamin D ◽  
Vertebral Fractures ◽  
Calcium Absorption ◽  
Elderly Women ◽  
Vitamin D Metabolites ◽  
Hydroxyvitamin D ◽  
Dihydroxyvitamin D ◽  
Significant Difference ◽  
Before And After ◽  
Calcium Malabsorption

1. Radio-calcium absorption, plasma 25-hydroxyvitamin D [25-(OH)D] and 1,25-dihydroxyvitamin D [1,25-(OH)2D] concentrations were measured in 19 elderly women with, and 21 without, vertebral fractures, before and after treatment with 25-hydroxyvitamin D3 [25-(OH)D3], to establish whether malabsorption of calcium in elderly women with vertebral fractures has a cause different from that in elderly women without vertebral fractures. 2. Malabsorption of calcium and low plasma 25-(OH)D and 1,25-(OH)2D concentrations were common in both groups of women but there was no significant difference in these variables between the two groups. 3. After treatment with 40 μg of 25-(OH)D3 daily for 7 days, there was a significant increase in plasma 25-(OH)D and 1,25-(OH)2D in both groups of women, but radio-calcium absorption increased significantly only in the group without vertebral fractures. 4. Elderly women with vertebral fractures have malabsorption of calcium which is resistant to the action of vitamin D metabolites at concentrations which correct calcium malabsorption in elderly women without vertebral fractures.

Regulation of 25-Hydroxy-Vitamin D-1α-Hydroxylase in Chick Isolated Renal Tubules: Effects of Prostaglandin E2, Frusemide and Acetylsalicylic Acid

1981 ◽  
Vol 61 (1) ◽  
pp. 53-59 ◽  
Author(s):  
J. D. Wark ◽  
R. G. Larkins ◽  
J. A. Eisman ◽  
K. R. Wilson
Keyword(s):  
Vitamin D ◽  
Prostaglandin E2 ◽  
Acetylsalicylic Acid ◽  
Vitamin D3 ◽  
Incubation Medium ◽  
Prostaglandin E ◽  
Renal Tubules ◽  
Endogenous Prostaglandin ◽  
25 Hydroxy Vitamin D ◽  
1,25 Dihydroxy Vitamin D3

1. Isolated renal tubules were prepared from vitamin D-deficient chicks. The effects of added prostaglandin E2 (PGE2) and agents which modify prostaglandin metabolism on the metabolism of 25-hydroxy-vitamin D3 were studied. 2. Frusemide (0.1 mmol/l) raised the prostaglandin E (PGE) content of the tubule incubation medium; it significantly increased 1,25-dihydroxy-vitamin D3 [1,25-(OH)2D3] production from 25-hydroxy-vitamin D3 [25-(OH)D3] and significantly inhibited the net production of 24,25-dihydroxy-vitamin D3 [24,25-(OH)2D3]. 3. Acetylsalicylic acid (aspirin; 0.1 mmol/l) decreased the PGE content of the tubule incubation medium and significantly inhibited 1,25-(OH)2D3 production. 4. In the presence of 1,25-(OH)2D3, 4 h exposure of tubules from vitamin D-deficient chicks to concentrations of PGE2 between 2.8 × 10−6 and 2.8 × 10−8 mol/l significantly enhanced 1,25-(OH)2D3 production. 5. It is concluded that, in view of the effects of modulation of endogenous prostaglandin levels by frusemide in aspirin, and the stimulatory effect of exogenous PGE2, prostaglandins should be considered potential regulators of the renal 25-hydroxy-vitamin D-1α-hydroxylase [25-(OH)D-1α-hydroxylase] enzyme.

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