Vitamin D Metabolism in Adult Rats at Low and Normal Calcium Intake and the Effect of Cadmium Exposure

1977 ◽  
Vol 53 (5) ◽  
pp. 439-446
Author(s):  
R. Lorentzon ◽  
S.-E. Larsson
Keyword(s):  
Vitamin D ◽  
Dietary Intake ◽  
Intestinal Mucosa ◽  
Vitamin D3 ◽  
Calcium Intake ◽  
Dietary Calcium ◽  
Cadmium Exposure ◽  
Dietary Calcium Intake ◽  
Adult Rats ◽  
25 Hydroxycholecalciferol

1. Chromatography measurements indicated that adult rats converted 25-hydroxycholecalciferol into 1,25-dihydroxycholecalciferol at a lower rate than that reported earlier for young animals. In serum, less-polar metabolites were found which probably represented vitamin D esters and vitamin D3. 2. A low dietary intake of calcium resulted in an evident increase in the fraction corresponding to 1,25-dihydroxycholecalciferol in the kidneys and also in the intestinal mucosa and serum. 3. Inclusion of 0·67 mmol of cadmium/l of drinking water at a low dietary intake of calcium resulted in an increased accumulation of both cadmium and zinc in the kidneys and liver compared with values at a normal dietary calcium intake. 4. At a normal dietary calcium intake, cadmium exposure caused inhibited production of 1,25-dihydroxycholecalciferol by the kidneys and an increased accumulation of 24,25-dihydroxycholecalciferol, vitamin D3 and vitamin D esters in the serum. 5. The inhibitory effect of cadmium on the renal conversion of 25-hydroxycholecalciferol into 1,25-dihydroxycholecalciferol was almost completely counteracted by a simultaneous low dietary calcium intake. Cadmium-exposed, calcium-deficient animals also showed a maintained accumulation of 1,25-dihydroxycholecalciferol in the intestinal mucosa.

scholarly journals Dietary Calcium Intake and Calcium Supplementation in Hungarian Patients with Osteoporosis

2013 ◽  
Vol 2013 ◽  
pp. 1-8
Author(s):  
Gábor Speer ◽  
Pál Szamosujvári ◽  
Péter Dombai ◽  
Katalin Csóré ◽  
Kinga Mikófalvi ◽  
...  
Keyword(s):  
Dietary Intake ◽  
Calcium Intake ◽  
Calcium Supplementation ◽  
Dietary Calcium ◽  
Dietary Calcium Intake ◽  
Current Recommendation ◽  
High Calcium Intake ◽  
Osteoporosis Therapy ◽  
Average Intake ◽  
High Calcium

Purpose. Adequate calcium intake is the basis of osteoporosis therapy—when this proves insufficient, even specific antiosteoporotic agents cannot exert their actions properly.Methods. Our representative survey analyzed the dietary intake and supplementation of calcium in 8033 Hungarian female and male (mean age: 68 years) (68.01 (CI95: 67.81–68.21)) patients with osteoporosis.Results. Mean intake from dietary sources was665±7.9 mg (68.01 (CI95: 67.81–68.21)) daily. A significant positive relationship could be detected between total dietary calcium intake and lumbar spine BMD (P=0.045), whereas such correlation could not be demonstrated with femoralT-score. Milk consumption positively correlated with femur (P=0.041), but not with lumbar BMD. The ingestion of one liter of milk daily increased theT-score by 0.133. Average intake from supplementation was558±6.2 mg (68.01 (CI95: 67.81–68.21)) daily. The cumulative dose of calcium—from both dietary intake and supplementation—was significantly associated with lumbar (r=0.024,P=0.049), but not with femur BMD (r=0.021,P=0.107). The currently recommended 1000–1500 mg total daily calcium intake was achieved in 34.5% of patients only. It was lower than recommended in 47.8% of the cases and substantially higher in 17.7% of subjects.Conclusions. We conclude that calcium intake in Hungarian osteoporotic patients is much lower than the current recommendation, while routinely applied calcium supplementation will result in inappropriately high calcium intake in numerous patients.

The impact of dietary calcium intake and vitamin D status on the effects of zoledronate

2012 ◽  
Vol 24 (1) ◽  
pp. 349-354 ◽  
Author(s):  
S. Bourke ◽  
M. J. Bolland ◽  
A. Grey ◽  
A. M. Horne ◽  
D. J. Wattie ◽  
...  
Keyword(s):  
Vitamin D ◽  
Calcium Intake ◽  
Dietary Calcium ◽  
Dietary Calcium Intake ◽  
Vitamin D Status ◽  
The Impact

Dietary calcium intake and serum vitamin D are major determinants of bone mass variations in women. A longitudinal study

2002 ◽  
Vol 14 (5) ◽  
pp. 382-388 ◽  
Author(s):  
Antonio del Puente ◽  
Antonella Esposito ◽  
Silvia Savastano ◽  
Assunta Carpinelli ◽  
Loredana Postiglione ◽  
...  
Keyword(s):  
Vitamin D ◽  
Longitudinal Study ◽  
Bone Mass ◽  
Calcium Intake ◽  
Serum Vitamin ◽  
Dietary Calcium ◽  
Dietary Calcium Intake ◽  
Serum Vitamin D

scholarly journals Dietary Calcium Intake, Vitamin D Status, and Bone Health in Postmenopausal Women in Rural Pakistan

2011 ◽  
Vol 29 (5) ◽  
Author(s):  
Nicola M Lowe ◽  
Basma Ellahi ◽  
Qudsia Bano ◽  
Sonia Ali Bangash ◽  
Soma R Mitra ◽  
...  
Keyword(s):  
Vitamin D ◽  
Postmenopausal Women ◽  
Bone Health ◽  
Calcium Intake ◽  
Dietary Calcium ◽  
Dietary Calcium Intake ◽  
Vitamin D Status ◽  
Rural Pakistan

The Effects of a Diphosphonate and Dietary Calcium on the Metabolism of Vitamin D3 (Cholecalciferol) in the Chick

1975 ◽  
Vol 49 (5) ◽  
pp. 391-400
Author(s):  
Carol M. Taylor ◽  
E. Barbara Mawer ◽  
A. Reeve
Keyword(s):  
Vitamin D ◽  
Oral Dose ◽  
Single Oral Dose ◽  
Vitamin D3 ◽  
Dietary Calcium ◽  
No Inhibition ◽  
25 Hydroxycholecalciferol

1. Vitamin D-deficient chicks, maintained on a diet adequate in calcium and treated with ethane-1-hydroxy-1,1-diphosphonate for 2 days before a single oral dose of cholecalciferol (vitamin D3), converted the vitamin into 24,25-dihydroxycholecalciferol instead of into the normal metabolite 1,25-dihydroxycholecalciferol. 2. This inhibition of the renal 1-hydroxylase disappeared on withdrawal of the diphosphonate. 3. Kidneys from chicks given diphosphonate for 12 days converted 25-hydroxycholecalciferol into 24,25-dihydroxycholecalciferol on incubation in vitro. 4. The inhibition of the 1-hydroxylase was markedly accelerated by treating the birds with cholecalciferol. 5. No inhibition of renal 1-hydroxylation was observed in birds maintained on a diet low in calcium. 6. A possible mechanism producing this effect is discussed.

scholarly journals Do Vitamin D Level and Dietary Calcium Intake Modify the Association Between Loop Diuretics and Bone Health?

2019 ◽  
Vol 106 (2) ◽  
pp. 104-114 ◽  
Author(s):  
Sadaf Oliai Araghi ◽  
Jessica C. Kiefte-de Jong ◽  
Katerina Trajanoska ◽  
Fjorda Koromani ◽  
Fernando Rivadeneira ◽  
...  
Keyword(s):  
Vitamin D ◽  
Bone Health ◽  
Calcium Intake ◽  
Trabecular Bone Score ◽  
Dietary Calcium ◽  
Population Based ◽  
Loop Diuretics ◽  
Dietary Calcium Intake ◽  
Mineral Density ◽  
Dxa Scan

Abstract Loop diuretics (LD) may affect bone health by inhibiting renal calcium reuptake. However, whether vitamin D status and dietary calcium intake modify the association between LD and bone outcome is unclear. Therefore, this study aimed to evaluate whether vitamin D level or calcium intake modify the association between LD and various indices of bone health including bone mineral density (BMD) and Trabecular Bone Score (TBS). From The Rotterdam Study, a prospective population-based cohort study, we used data from 6990 participants aged > 45 year with a DXA scan (2002–2008), 6908 participants with femoral neck (FN)-BMD, 6677 participants with lumbar spine (LS)-BMD and 6476 participants with LS-TBS measurements. Use of LD was available from pharmacy dispensing records. Vitamin D (25(OH)D) level was measured in serum, and dietary calcium intake was measured with a validated food frequency questionnaire. Almost eight percent of the participants used LD. The association between LD (past-users compared to never-users) and LS-TBS was significantly different by 25(OH)D concentrations (P for interaction = 0.04). A significantly lower LS-TBS among LD past-users was observed for 25(OH)D ≥ 50 nmol/l compared to ≤ 20 and 20–50 nmol/l (β = − 0.036, 95% CI − 0.060; − 0.013 vs. β = − 0.012, 95% CI − 0.036; 0.013 and β = − 0.031, 95% CI − 0.096; 0.034, respectively). However, no other significant effect modification by 25(OH)D and dietary calcium intake was found in the associations between LD use and bone health outcomes (P-interaction > 0.13). This study suggests that the association between LD use and indices of bone health is not consistently modified by vitamin D or dietary calcium intake.

The effect of dietary calcium on the activity of 25-hydroxycholecalciferol-l-hydroxylase and Ca absorption in vitamin D-replete chicks

1977 ◽  
Vol 38 (1) ◽  
pp. 47-54 ◽  
Author(s):  
R. Swaminathan ◽  
Barbara A. Sommerville ◽  
A. D. Care
Keyword(s):  
Vitamin D ◽  
Dietary Intake ◽  
Specific Activity ◽  
Dietary Calcium ◽  
Duodenal Mucosa ◽  
List Type ◽  
Type Number ◽  
Hydroxylase Activity ◽  
Dietary Level ◽  
25 Hydroxycholecalciferol

1.As most of the studies on the regulation of renal 25-hydroxycholecalciferol-1-hydroxylase (25-HCC-1-hydroxylase) activity have been done in marginally-vitamin D-defieient animals and as it is known that vitamin D administration suppresses the specific activity of the 25-HCC-1-hydroxylase, it was decided to study the effect of dietary calcium on the activity of 25-HCC-1-hydroxylase and on Ca absorption in vitamin Dreplete chicks.2.Chicks, 10 d old, were given diets differing in their Ca contents (65 nmol cholecalciferol/kg diet) for 10 d and the activity of 25-HCC-1-hydroxylase in kidney homogenates, Ca absorption from the duodenum, Cabinding protein (CaBP) activity in the duodenal mucosa and plasma Ca and phosphate concentrations were all determined.3.The CaBP activity and the efficiency of Ca absorption both decreased with increasing dietary intake of Ca. Ca absorption and CaBP activity were significantly correlated (r 0.995, P < 0.01).4.The activity of 25-HCC-1-hydroxylase decreased as the dietary level of Ca increased and was significantly correlated with Ca absorption (r0.900, P < 005). The plasma Ca concentration and the activity of 25-HCC-1-hydroxylase were inversely related (r-0.940, P < 0.01).5.It is concluded that in the vitamin D-replete chick the efficiency of duodenal Ca absorption is regulated by the renal 25-HCC-1-hydroxylase activity via production of 1,25-dihydroxycholecalciferol and CaBP synthesis.

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