scholarly journals Age-Related Changes in the 25-Hydroxyvitamin D Versus Parathyroid Hormone Relationship Suggest a Different Reason Why Older Adults Require More Vitamin D

2003 ◽  
Vol 88 (1) ◽  
pp. 185-191 ◽  
Author(s):  
Reinhold Vieth ◽  
Yasmin Ladak ◽  
Paul G. Walfish
Keyword(s):  
Older Adults ◽  
Vitamin D ◽  
Secondary Hyperparathyroidism ◽  
Age Groups ◽  
The Elderly ◽  
Age Group ◽  
Hydroxyvitamin D ◽  
Age Related ◽  
25 Hydroxyvitamin D ◽  
The Relationship

Vitamin D requirements are thought to vary with age, but there is little comparative evidence for this. One goal in establishing a vitamin D requirement is to avoid secondary hyperparathyroidism. We studied 1741 euthyroid, thyroid clinic outpatients without evidence of calcium abnormalities, ranging in age from 19 to 97 yr, whose serum and urine had been analyzed for calcium, vitamin D, and parathyroid status. We found no effect of age on the 25-hydroxyvitamin D [25(OH)D] concentration associated with specific vitamin D intakes, and there was no relationship between 25(OH)D and 1,25hydroxyvitamin D [1,25(OH)2D]. In every age group, serum 1,25(OH)2D declined with increasing creatinine (P < 0.001). What changed with age included creatinine, which correlated with 25(OH)D (r = 0.146, P < 0.001) only in the youngest age group (19–50 yr) but not in the older age groups (P > 0.1). Creatinine did not correlate with PTH in the youngest age group, but the relationship became significant as age increased (e.g. for the elderly, r = 0.365, P < 0.001). Linear regression of log PTH vs. log 25(OH)D agreed with the natural shape of the relationship observed with scatterplot smoothing, and this showed no plateau in PTH as 25(OH)D increased. We compared PTH concentrations among age groups, based on 20 nmol/liter increments in 25(OH)D. Mean PTH in adults older than 70 yr was consistently higher than in adults younger than 50 yr (P < 0.05 by ANOVA and Dunnett’s t test). PTH levels of the elderly who had 25(OH)D concentrations greater than 100 nmol/liter matched PTH of younger adults having 25(OH)D concentrations near 70 nmol/liter. This study shows that all age groups exhibit a high prevalence of 25(OH)D insufficiency and secondary hyperparathyroidism. Older adults are just as efficient in maintaining 25(OH)D, but they need more vitamin D to produce the higher 25(OH)D concentrations required to overcome the hyperparathyroidism associated with their diminishing renal function.

scholarly journals Age-related alteration of vitamin D metabolism in response to low-phosphate diet in rats

2005 ◽  
Vol 93 (3) ◽  
pp. 299-307 ◽  
Author(s):  
Tsui-Shan Chau ◽  
Wan-Ping Lai ◽  
Pik-Yuen Cheung ◽  
Murray J. Favus ◽  
Man-Sau Wong
Keyword(s):  
Vitamin D ◽  
Mrna Expression ◽  
Age Groups ◽  
Metabolic Clearance ◽  
Adult Rats ◽  
Vitamin D Metabolism ◽  
Hydroxyvitamin D ◽  
Dihydroxyvitamin D ◽  
Age Related ◽  
25 Hydroxyvitamin D

The responses of renal vitamin D metabolism to its major stimuli alter with age. Previous studies showed that the increase in circulating 1,25-dihydroxyvitamin D (1,25(OH)2D3) as well as renal 25-hydroxyvitamin D3 1-α hydroxylase (1-OHase) activity in response to dietary Ca or P restriction reduced with age in rats. We hypothesized that the mechanism involved in increasing circulating 1,25(OH)2D3 in response to mineral deficiency alters with age. In the present study, we tested the hypothesis by studying the expression of genes involved in renal vitamin D metabolism (renal 1-OHase, 25-hydroxyvitamin D 24-hydroxylase (24-OHase) and vitamin D receptor (VDR)) in young (1-month-old) and adult (6-month-old) rats in response to low-phosphate diet (LPD). As expected, serum 1,25(OH)2D3 increased in both young and adult rats upon LPD treatment and the increase was much higher in younger rats. In young rats, LPD treatment decreased renal 24-OHase (days 1–7, P<0·01) and increased renal 1-OHase mRNA expression (days 1–5, P<0·01). LPD treatment failed to increase renal 1-OHase but did suppress 24-OHase mRNA expression (P<0·01) within 7 d of LPD treatment in adult rats. Renal expression of VDR mRNA decreased with age (P<0·001) and was suppressed by LPD treatment in both age groups (P<0·05) Feeding of adult rats with 10 d of LPD increased 1-OHase (P<0·05) and suppressed 24-OHase (P<0·001) as well as VDR (P<0·05) mRNA expression. These results indicate that the increase in serum 1,25(OH)2D3 level in adult rats during short-term LPD treatment is likely to be mediated by a decrease in metabolic clearance via the down-regulation of both renal 24-OHase and VDR expression. The induction of renal 1-OHase mRNA expression in adult rats requires longer duration of LPD treatment than in younger rats.

The Relationship Between Vitamin D and Telomere/Telomerase: a comprehensive review

2020 ◽  
pp. 1-8
Author(s):  
M. Zarei ◽  
M. Zarezadeh ◽  
F. Hamedi Kalajahi ◽  
M.H. Javanbakht
Keyword(s):  
Vitamin D ◽  
Telomere Length ◽  
Genomic Stability ◽  
Telomerase Activity ◽  
Cellular Aging ◽  
Hydroxyvitamin D ◽  
Age Related ◽  
25 Hydroxyvitamin D ◽  
Telomere Biology ◽  
The Relationship

Telomeres are repetitive nucleotide sequences that together with the associated sheltrin complex protect the ends of chromosomes and maintain genomic stability. Evidences from various organisms suggests that several factors influence telomere length regulation, such as telomere binding proteins, telomere capping proteins, telomerase, and DNA replication enzymes. Recent studies suggest that micronutrients, such as vitamin D, folate and vitamin B12, are involved in telomere biology and cellular aging. In particular, vitamin D is important for a range of vital cellular processes including cellular differentiation, proliferation and apoptosis. As a result of the multiple functions of vitamin D it has been speculated that vitamin D might play a role in telomere biology and genomic stability. In this study, our main goal is investigating the relationship between telomerase enzyme and vitamin D. Findings of this study suggest that higher vitamin D concentrations, which are easily modifiable through nutritional supplementation, are associated with longer LTL, which underscores the potentially beneficial effects of this hormone on aging and age-related diseases. Vitamin D may reduce telomere shortening through anti-inflammatory and anti-cell proliferation mechanisms. Significant Low levels of telomerase activity create short telomeres, which in turn signal exit from the cell cycle resulting in cell senescence and apoptosis. In follow-up examination, the patients who remained vitamin D deficient tended to have shorter telomeres than those patients whose 25-hydroxyvitamin D levels were depleted. Increasing 25-hydroxyvitamin D levels in patients with SLE may be beneficial in maintaining telomere length and preventing cellular aging. Moreover, anti-telomere antibody levels may be a promising biomarker of SLE status and disease activity.

scholarly journals Relationship Between Level of Serum 25-Hydroxyvitamin D and Risk of Squamous Cell Carcinoma in an Iranian Population

2019 ◽  
pp. 278-282
Author(s):  
Mahboobeh-Sadat Hosseini ◽  
Fereshteh Salarvand ◽  
Amir Houshang Ehsani ◽  
Pedram Noormohammadpour ◽  
Shadi Azizzadeh ◽  
...  
Keyword(s):  
Vitamin D ◽  
Squamous Cell Carcinoma ◽  
Cell Carcinoma ◽  
Squamous Cell ◽  
Outdoor Environment ◽  
Hydroxyvitamin D ◽  
Vitamin D Levels ◽  
History Of ◽  
25 Hydroxyvitamin D ◽  
The Relationship

Background: The relationship between vitamin D and skin squamous cell carcinoma (SCC) is not well defined. Objective: To investigate the relationship between vitamin D levels and the incidence of skin SCC for the first time in Iran. Methods and Study Design: In this case-control study, 126 subjects were enrolled (63 in each group) out of referents to Razi Skin Hospital in Tehran in 2014. The risk factors for cancer gathered by self-reported questionnaires and blood samples were obtained to measure the level of 25-hydroxyvitamin D. Multivariate logistic regression was used to neutralize the effect of confounding factors. Results: Cases of SCC were more likely to be in men, older than 49 years and working in an outdoor environment, and with longtime exposure to sunlight and a personal history of skin cancers. Family history of skin cancer and of cigarette smoking were not significantly related to SCC. In the SCC and control groups, 69.8% and 31.7%, respectively, had sufficient levels of vitamin D (P < 0.001). Mean level of 25-hydroxyvitamin D was 40.99 ng/mL in the SCC group and 26.34 ng/mL in the control group (P < 0.05). In the unadjusted model, the level of vitamin D as a continuous variable was positively related to SCC risk. In the adjusted model, vitamin D did not independently predict the likelihood of SCC. Conclusion: Vitamin D level and SCC risk are directly related, although not in an independent fashion. Indeed, this relation is severely confounded by exposure to sunlight, which was evidenced by an increased vitamin D level in the people working outside and the higher prevalence of SCC in the same population.

scholarly journals Determinants of serum 25-hydroxyvitamin D in Hong Kong

2015 ◽  
Vol 114 (1) ◽  
pp. 144-151 ◽  
Author(s):  
Cuiling Xu ◽  
Ranawaka A. P. M. Perera ◽  
Yap-Hang Chan ◽  
Vicky J. Fang ◽  
Sophia Ng ◽  
...  
Keyword(s):  
Vitamin D ◽  
Hong Kong ◽  
Southern China ◽  
Age Groups ◽  
Dietary Vitamin ◽  
Skeletal Health ◽  
Mean Values ◽  
Hydroxyvitamin D ◽  
25 Hydroxyvitamin D ◽  
The Mean

Vitamin D plays an important role in skeletal health throughout life. Some studies have hypothesised that vitamin D may reduce the risk of other diseases. Our study aimed to estimate age-specific and sex-specific serum 25-hydroxyvitamin D (25(OH)D) status and to identify the determinants of serum 25(OH)D status in Hong Kong, a subtropical city in southern China. In 2009–2010, households in Hong Kong were followed up to identify acute respiratory illnesses, and sera from 2694 subjects were collected in three to four different study phases to permit measurement of 25(OH)D levels at different times of the year. A questionnaire survey on diet and lifestyle was conducted among children, with simultaneous serum collection in April and May 2010. The mean of serum 25(OH)D levels in age groups ranged from 39 to 63 nmol/l throughout the year with the mean values in all age groups in spring below 50 nmol/l. Children aged 6–17 years, and girls and women had significantly lower serum 25(OH)D levels than adults, and boys and men, respectively (allP< 0·001). We estimated that serum 25(OH)D levels in Hong Kong followed a lagged pattern relative to climatic season by 5 weeks with lowest observed levels in early spring (March). For children aged 6–17 years, reporting a suntan, having at least 1 servings of fish/week and having at least 1 serving of eggs/week were independently associated with higher serum 25(OH)D levels. Adequate sunlight exposure and increased intake of dietary vitamin D could improve vitamin D status, especially for children and females in the winter and spring.

scholarly journals Vitamin D status and secondary hyperparathyroidism: The importance of 25-hydroxyvitamin D cut-off levels

2003 ◽  
Vol 63 ◽  
pp. S44-S48 ◽  
Author(s):  
Carlos Gómez-Alonso ◽  
Manuel L. Naves-Díaz ◽  
Jose L. Fernández-Martín ◽  
Jose B. Díaz-López ◽  
Maria T. Fernández-Coto ◽  
...  
Keyword(s):  
Vitamin D ◽  
Secondary Hyperparathyroidism ◽  
Vitamin D Status ◽  
Hydroxyvitamin D ◽  
25 Hydroxyvitamin D

scholarly journals Epidemiology of the association between serum 25-hydroxyvitamin D levels and musculoskeletal conditions among elderly individuals: a literature review

2020 ◽  
Vol 39 (1) ◽  
Author(s):  
Kazuhiko Arima ◽  
Satoshi Mizukami ◽  
Takayuki Nishimura ◽  
Yoshihito Tomita ◽  
Hiroki Nakashima ◽  
...  
Keyword(s):  
Older Adults ◽  
Vitamin D ◽  
Risk Factor ◽  
Vitamin D Deficiency ◽  
Muscle Weakness ◽  
Elderly Individuals ◽  
Musculoskeletal Conditions ◽  
Hydroxyvitamin D ◽  
25 Hydroxyvitamin D ◽  
Osteoporosis Fracture

Abstract Background Vitamin D deficiency is associated with osteoporosis, fracture, muscle weakness, falls, and osteoarthritis in adults. Elderly individuals are more likely to present with poor musculoskeletal conditions. Recently, several epidemiological studies have assessed the correlation between serum 25-hydroxyvitamin D (25(OH)D) levels and musculoskeletal conditions in elderly individuals. Main text Osteoporosis is a skeletal disease characterized by low bone mass and microarchitectural deterioration of bone tissue, with a consequent increase in bone fragility and susceptibility to fracture. Numerous studies have shown a positive association between serum 25(OH)D levels and bone mineral density. Only a few studies have reported an association between serum 25(OH)D levels and quantitative ultrasound (QUS) parameters. Low serum 25(OH)D level may be a risk factor for hip fracture. However, data on the association between vitamin D deficiency and the incidence of non-hip fracture are contrasting. Falls are a major cause of mortality and morbidity in older adults. Several prospective population-based cohort studies have shown that low 25(OH)D levels are associated with an increased risk of falls. Reduced muscle strength and physical performance are risk factors for adverse events, including disability, institutionalization, and mortality. The role of vitamin D in musculoskeletal functionality (muscle weakness and physical performance) among elderly individuals is still controversial. Osteoarthritis (OA) is the most common form of arthritis and is a leading cause of disability among older adults. Data on the association between serum 25(OH)D levels and OA are contrasting. Conclusion Some studies have shown that vitamin D deficiency may be a risk factor for poor musculoskeletal conditions, such as osteoporosis, fracture, muscle weakness, falls, and osteoarthritis in adults. However, other studies did not find an association between serum 25(OH)D levels and musculoskeletal conditions.

Role of vitamin D and sFlt-1/PlGF ratio in the development of early- and late-onset preeclampsia

2015 ◽  
Vol 53 (7) ◽  
Author(s):  
Indira Álvarez-Fernández ◽  
Belén Prieto ◽  
Verónica Rodríguez ◽  
Yolanda Ruano ◽  
Ana I. Escudero ◽  
...  
Keyword(s):  
Vitamin D ◽  
Late Onset ◽  
Tertiary Care ◽  
Care Hospital ◽  
Hydroxyvitamin D ◽  
Increased Risk ◽  
25 Hydroxyvitamin D ◽  
The Relationship ◽  
Plgf Ratio

AbstractThe imbalanced production of placental biomarkers and vitamin D deficiency have been proposed as risk factors for the development of preeclampsia (PE). However, little is known about the relationship between them and their role in early- versus late-onset PE. The objectives were to assess the role of 25-hydroxyvitamin D [25(OH)D] concentrations and the soluble fms-like tyrosine kinase 1 (sFlt-1) to placental growth factor (PlGF) ratio in the development of early- and late-onset PE; and to evaluate the relationship between 25(OH)D and the biomarkers.A retrospective, full-blinded cohort study was conducted at the Obstetric Emergency Service of a tertiary care hospital. Pregnant women (n=257) attending obstetric triage with suspicion of PE were included. sFlt-1, PlGF and 25(OH)D concentrations were measured by electrochemoluminescence (ECLIA) immunoassay and pregnancy outcome (development of PE) was registered from patients records.PE women showed lower 25(OH)D concentrations at clinical presentation than non-PE women (median: 35.0 nmol/L and 39.6 nmol/L, respectively; p=0.027). Women with 25(OH)D levels <50 nmol/L experienced an increased risk of developing late-onset PE [odds ratio (OR) 4.6, 95% confidence interval (CI) 1.4–15], but no association was found for early-onset PE. However, a sFlt-1/PlGF ratio above the corresponding cutpoints increased the risk of developing both early- and late-onset PE [ORs 58 (95% CI 11–312) and 12 (95% CI 5.0–27), respectively]. No association was found between 25(OH)D levels and sFlt-1/PlGF ratio.Low vitamin D status in women with suspected late-onset PE increases the risk of imminent development of the disease.

scholarly journals Very high rates of vitamin D insufficiency in women of child-bearing age living in Beijing and Hong Kong

2008 ◽  
Vol 99 (6) ◽  
pp. 1330-1334 ◽  
Author(s):  
Jean Woo ◽  
Christopher W. K. Lam ◽  
Jason Leung ◽  
Winny Y. Lau ◽  
Edith Lau ◽  
...  
Keyword(s):  
Vitamin D ◽  
Hong Kong ◽  
Pregnant Women ◽  
Vitamin D Deficiency ◽  
Vitamin D Insufficiency ◽  
Dietary Intakes ◽  
Hydroxyvitamin D ◽  
The North ◽  
25 Hydroxyvitamin D ◽  
The Relationship

We aimed to describe the vitamin D status of young women living in two Chinese cities in the spring – Beijing in the north (latitude 39° north) and Hong Kong (latitude 22° north) in the south. We also examined the relationship between serum 25-hydroxyvitamin D and parathyroid hormone (PTH) concentrations to determine a threshold for serum 25-hydroxyvitamin D above which there is no further suppression of PTH. Finally, we examined whether dietary Ca intake influences this relationship. Non-pregnant women aged 18–40 years (n 441) were recruited between February and June. Fasting blood was collected and dietary intakes were assessed using 5 d food records. Mean serum 25-hydroxyvitamin D concentration was lower in Beijing than Hong Kong women (29 v. 34 nmol/l; P < 0·001). Vitamin D deficiency ( ≤  25 nmol/l) was indicated in 40 % of Beijing and 18 % of Hong Kong women, and over 90 % of women in both cities were insufficient ( ≤ 50 nmol/l). Mean Ca and vitamin D intakes were 478 mg/d and 2·0 μg/d, respectively. The relationship between 25-hydroxyvitamin D concentration and PTH was linear throughout the range with a slope of − 0·36 (different from 0; P < 0·001; R 0·26), with no apparent threshold. There was no influence of Ca intake on the relationship between 25-hydroxyvitamin D and PTH concentration. Vitamin D deficiency is common and insufficiency is very common in non-pregnant women in Hong Kong and Beijing during spring. Serum 25-hydroxyvitamin D was inversely associated with PTH with no apparent threshold. Strategies such as vitamin D fortification or supplementation may be required.

scholarly journals Associations of Sun Exposure with 25-Hydroxyvitamin D and Parathyroid Hormone Levels in a Cohort of Hypertensive Patients: The Graz Endocrine Causes of Hypertension (GECOH) Study

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Stefan Pilz ◽  
Katharina Kienreich ◽  
Daniel Stückler ◽  
Andreas Meinitzer ◽  
Andreas Tomaschitz
Keyword(s):  
Vitamin D ◽  
Parathyroid Hormone ◽  
Scalp Hair ◽  
Sun Exposure ◽  
Hypertensive Patients ◽  
Hydroxyvitamin D ◽  
Outdoor Sports ◽  
25 Hydroxyvitamin D ◽  
Relationship Of ◽  
The Relationship

Sunlight-induced vitamin D, synthesis in the skin is the major source of vitamin D, but data on the relationship of sun-related behaviour with vitamin D and parathyroid hormone (PTH) levels are relatively sparse. We evaluated whether habitual sun exposure is associated with 25-hydroxyvitamin D (25[OH]D) and PTH levels and whether there exist seasonal variations. We examined 111 hypertensive patients in Austria (latitude 47° N). Frequent sunbathing at home and outdoor sports were associated with higher 25(OH)D levels (P<0.05for both). Red or blond scalp hair as a child, memory of sunburns, preferring sunbathing, frequent stays on the beach or in open-air pools, and solarium use were associated with lower PTH levels (P<0.05for all). Multiple linear regression analyses including age, sex, and body mass index showed that sun exposure score was significantly associated with 25(OH)D (betacoefficient=0.27;P=0.004) and by trend with PTH (betacoefficient=−0.16;P=0.09). These associations were more prominent in summer in which 25(OH)D levels were significantly higher compared to winter. Translation of these findings into recommendations for the prevention and treatment of vitamin D deficiency remains a challenge for the future.

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