scholarly journals Vitamin D, phosphate, and vasculotoxicity

2015 ◽  
Vol 93 (12) ◽  
pp. 1077-1082 ◽  
Author(s):  
Ronald B. Brown ◽  
Afrozul Haq ◽  
Charles F. Stanford ◽  
Mohammed S. Razzaque

Vascular calcification is a complex process that results in the ectopic deposition of calcium-phosphate hydroxyapatite. Medial and intimal vascular calcification is frequently present in patients with diabetes mellitus and chronic kidney disease (CKD), and markedly increases the morbidity and mortality of these patients. Increased serum levels of calcium and phosphate, along with the use of active vitamin D metabolites, are commonly implicated in the evolvement of vascular wall mineralization in CKD patients. Because CKD patients have lower serum levels of vitamin D, they are routinely prescribed vitamin D supplements that exert a dualistic role that is both healthful and harmful in these patients, perhaps protecting bone health, but at the expense of promoting vascular pathology. This review briefly explains how reducing the phosphate burden in CKD patients could minimize vitamin-D-associated vascular wall calcification.

Author(s):  
Jan Mieszkowski ◽  
Andrzej Kochanowicz ◽  
Elżbieta Piskorska ◽  
Bartłomiej Niespodziński ◽  
Joanna Siódmiak ◽  
...  

Abstract Purpose/introduction To compare serum levels of bone turnover markers in athletes and non-athletes, and to evaluate the relationship between serum levels of vitamin D metabolites and exercise-induced changes in biomarker levels. Methods Sixteen elite male artistic gymnasts (EG; 21.4 ± 0.8 years-old) and 16 physically active men (the control group, PAM; 20.9 ± 1.2 years-old) performed lower and upper body 30-s Wingate anaerobic tests (LBWT and UBWT, respectively). For biomarker analysis, blood samples were collected before, and 5 and 30 min after exercise. Samples for vitamin D levels were collected before exercise. N-terminal propeptide of type I collagen (PINP) was analysed as a marker of bone formation. C-terminal telopeptide of type I collagen (CTX) was analysed as a marker of bone resorption. Results UBWT fitness readings were better in the EG group than in the PAM group, with no difference in LBWT readings between the groups. UBWT mean power was 8.8% higher in subjects with 25(OH)D3 levels over 22.50 ng/ml and in those with 24,25(OH)2D3 levels over 1.27 ng/ml. Serum CTX levels increased after both tests in the PAM group, with no change in the EG group. PINP levels did not change in either group; however, in PAM subjects with 25(OH)D3 levels above the median, they were higher than those in EG subjects. Conclusion Vitamin D metabolites affect the anaerobic performance and bone turnover markers at rest and after exercise. Further, adaptation to physical activity modulates the effect of anaerobic exercise on bone metabolism markers.


2021 ◽  
pp. jim-2020-001645
Author(s):  
Laura D Carbone ◽  
Karen Johnson ◽  
Joseph C Larson ◽  
Fridtjof Thomas ◽  
Jean Wactawski-Wende ◽  
...  

The relationship between vitamin D and glaucoma is controversial. The objective of this study was to examine women from the Women’s Health Initiative (WHI) to determine if there is an association between vitamin D and incident glaucoma in postmenopausal women. We examined the association between dietary vitamin D intake, vitamin D supplements and serum 25 hydroxyvitamin D (25(OH)D) levels and the risk of developing glaucoma. 143,389 postmenopausal women from the WHI including a subset with serum 25(OH) D measurements were examined to determine the association of dietary, supplemental and serum levels of vitamin D to the development of glaucoma. Dietary intakes of vitamin D, use of vitamin D supplements and serum levels of 25(OH) D were predictors examined for the main outcome of incident glaucoma. In multivariable models adjusted for demographic, clinical variables and medication use, dietary vitamin D, vitamin D supplements, total vitamin D intake (diet plus supplements) and serum 25 (OH) D measurements were not significantly associated with incident glaucoma. In the CaD placebo-controlled intervention clinical trial, there was also no association in the active intervention arm with glaucoma. We conclude that dietary vitamin D intake, supplements and serum levels are not significantly related to the risk of developing glaucoma in postmenopausal women.


1986 ◽  
Vol 10 (2) ◽  
pp. 191-194 ◽  
Author(s):  
Saburo Kimura ◽  
Osamu Nose ◽  
Tokuzo Harada ◽  
Ichiro Maki ◽  
Shinobu Kanaya ◽  
...  

Nutrients ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 2778 ◽  
Author(s):  
Carmelinda Ruggiero ◽  
Marta Baroni ◽  
Vittorio Bini ◽  
Annalisa Brozzetti ◽  
Luca Parretti ◽  
...  

Vitamin D inadequacy is pervasive in the oldest-old. Many vitamin D metabolites are available for supplementation, their effects on the recovery of adequate serum levels remain unknown. We investigate the effects of supplementation with cholecalciferol (D3) and calcifediol (25D3) on serum levels of 25(OH)D, 1-25(OH)D, bone and inflammatory markers, ultimately identifying clinical predictors of successful treatment. Sixty-seven oldest-old individuals were randomized to weekly administration of 150 mcg of 25D3 or D3, from hospital admission to 7 months after discharge. Supplementation of 25D3 and D3 were associated with increasing serum levels of 25(OH)D (p < 0.001) and 1-25(OH)D (p = 0.01). Participants on 25D3 experienced a steeper rise than those on D3 (group*time interaction p = 0.01), after adjustment for intact parathyroid hormone (iPTH) levels the differences disappeared (intervention*iPTH interaction p = 0.04). Vitamin D supplementation was associated with a decreasing trend of iPTH and C-reactive protein (CRP) (p < 0.001). Polypharmacy and low handgrip strength were predictors of failure of intervention, independent of vitamin D metabolites. In conclusion, D3 and 25D3 supplementation significantly increase vitamin D serum levels in the oldest-old individuals, with a tendency of 25D3 to show a faster recovery of acceptable iPTH levels than D3. Polypharmacy and low muscle strength weaken the recovery of adequate vitamin D serum levels.


Nutrients ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3629 ◽  
Author(s):  
Jan Mieszkowski ◽  
Błażej Stankiewicz ◽  
Andrzej Kochanowicz ◽  
Bartłomiej Niespodziński ◽  
Tomasz Kowalik ◽  
...  

Purpose: While an increasing number of studies demonstrate the importance of vitamin D for athletic performance, the effects of any type of exercise on vitamin D metabolism are poorly characterized. We aimed to identify the responses of some vitamin D metabolites to ultra-marathon runs. Methods: A repeated-measures design was implemented, in which 27 amateur runners were assigned into two groups: those who received a single dose of vitamin D3 (150,000 IU) 24 h before the start of the marathon (n = 13) and those (n = 14) who received a placebo. Blood samples were collected 24 h before, immediately after, and 24 h after the run. Results: In both groups of runners, serum 25(OH)D3, 24,25(OH)2D3, and 3-epi-25(OH)D3 levels significantly increased by 83%, 63%, and 182% after the ultra-marathon, respectively. The increase was most pronounced in the vitamin D group. Body mass and fat mass significantly decreased after the run in both groups. Conclusions: Ultra-marathon induces the mobilization of vitamin D into the blood. Furthermore, the 24,25(OH)2D3 and 3-epi-25(OH)D3 increases imply that the exercise stimulates vitamin D metabolism.


1991 ◽  
Vol 125 (2) ◽  
pp. 127-131 ◽  
Author(s):  
Gorm Thamsborg ◽  
Tommy L. Storm ◽  
Henrik Daugaard ◽  
Søren Schifter ◽  
Ole H. Sørensen

Abstract. Circulating levels of calciotropic hormones were measured during one year of treatment with either 200 IU of salmon calcitonin daily or placebo as a nasal spray in 20 postmenopausal women with a former Colles' fracture. A supplement of 0.5 gram elemental calcium was given to all participants. Serum levels of parathyroid hormone and human calcitonin were determined with radioimmunoassays, and serum levels of vitamin D metabolites were determined with protein binding assays. We did not find any significant differences between the two groups with respect to serum levels of calciotropic hormones. In the salmon calcitonin treated group there was a tendency towards a small decrease in serum levels of human calcitonin and an increase in serum levels of calcitriol. Our results suggest that treatment with 200 IU of salmon calcitonin daily as a nasal spray does not markedly affect fasting serum levels of parathyroid hormone, human calcitonin, and vitamin D metabolitis.


2020 ◽  
Vol 9 ◽  
pp. 1592
Author(s):  
Babak Pezeshki ◽  
Ali Ahmadi ◽  
Aliasghar Karimi

Background: Subclinical hypothyroidism (SCH) is characterized by an elevated Thyroid Stimulating Hormone (TSH) with a normal T4. The prevalence of Vitamin D deficiency in patients SCH is high. Some studies suggested that Vitamin D supplements could be reduced serum concentration of TSH so improve SCH and prevent overt hypothyroidism. This study aims to explore the effect of vitamin D replacement on subclinical hypothyroidism. Materials and Methods: Fifty-nine patients, diagnosed with both subclinical hypothyroidism and Vitamin D deficiency by the Endocrinology outpatient clinics between January 2018 and March 2019, were included in this trial. The patients with overt hypothyroidism, cardiovascular risk factors, or positive TPO antibody, abnormal T4, and pregnant women were excluded from this study. The 40 subjects were investigated who received vitamin D supplements for two months.  Analyses were conducted through paired-samples t-test and independent-samples t-test using SPSS 24 (Armonk, NY: IBM Corp). Results: The mean serum levels of TSH was decreased from 6.89 mIU/l in the pre-test to 3.34 mIU/l in the post-test, and the difference was found to be statistically significant at P<0.001. Conclusion: We found that the TSH mean level significantly dropped through the use of vitamin D supplements. Thus, it is recommended that all the patients with subclinical hypothyroidism be screened and treated with vitamin D supplements. [GMJ.2020;9:e1592]


2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Haipeng Yao ◽  
Zhen Sun ◽  
Guangyao Zang ◽  
Lili Zhang ◽  
Lina Hou ◽  
...  

Vascular calcification is the transformation of arterial wall mesenchymal cells, particularly smooth muscle cells (SMCs), into osteoblast phenotypes by various pathological factors. Additionally, vascular transformation mediates the abnormal deposition of calcium salts in the vascular wall, such as intimal and media calcification. Various pathological types have been described, such as calcification and valve calcification. The incidence of vascular calcification in patients with diabetes is much higher than that in nondiabetic patients, representing a critical cause of cardiovascular events in patients with diabetes. Because basic research on the clinical transformation of vascular calcification has yet to be conducted, this study systematically expounds on the risk factors for vascular calcification, vascular bed differences, sex differences, ethnic differences, diagnosis, severity assessments, and treatments to facilitate the identification of a new entry point for basic research and subsequent clinical transformation regarding vascular calcification and corresponding clinical evaluation strategies.


1987 ◽  
Vol 253 (4) ◽  
pp. F712-F718
Author(s):  
C. H. Hsu ◽  
C. S. Yang ◽  
S. R. Patel ◽  
M. G. Stevens

We have studied the effect of dietary vitamin D restriction on serum levels of vitamin D metabolites in spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto rats (WKY). Both WKY and SHR were fed a vitamin D-deficient or a vitamin D-supplemented diet beginning at 4 wk of age. In vitamin D-supplemented animals, the serum 1,25-dihydroxycholecalciferol [1,25(OH)2D3] concentration of WKY (55.4+/- 6.6 pg/ml, n = 5) was similar to the level of SHR (46.3+/- 5.9 pg/ml, n = 5). Plasma calcium concentration was not different between WKY and SHR. In animals fed a vitamin D-deficient diet, the serum concentration of 1,25-(OH)2D3 of SHR (23.0+/- 1.3 pg/ml, n = 5) was significantly lower than that of WKY (67.6+/- 4.6 pg/ml, n = 5, P less than 0.01). Plasma 25-hydroxycholecalciferol level was markedly decreased in both WKY (3.6+/- 0.5 ng/ml, n = 7) and SHR (2.8+/- 0.4 ng/ml). The SHR, but not the WKY, developed hypocalcemia (WKY, 9.68 mg/dl; SHR, 6.70 mg/dl). Despite hypocalcemia, fasting urinary Ca2+ excretion of SHR exceeded that of WKY. We conclude that the lower 1,25(OH)2D3 level in SHR fed a vitamin D-deficient diet may be due to a defect in the synthesis of 1,25(OH)2D3. The low level of 1,25(OH)2D3 is associated with renal wasting of calcium and hypocalcemia in SHR.


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