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1.
The vitamin D state of 60 apparently healthy adult Hindu Asian couples living in Britain was studied on a community basis. Twenty six (22%) of the Asian subjects had pronounced vitamin D deficiency, defined as 25-hydroxycholecalciferol concentrations below 10 nmol/l (4 ng/ml), while none of the white controls had such low concentrations. Asian men and women were equally affected, and plasma concentrations were similar in husbands and wives. Vitamin supplements were being taken by only 31 (26%) subjects, most of whom were women. It is suggested that the spouses of patients with osteomalacia should be screened for vitamin D deficiency.  相似文献   

2.
Serum concentrations of 25-hydroxy vitamin D (25-OHD3) were measured in seven Asians of Indian extraction and eight Europeans before and at intervals after taking 1 mg vitamin D3 by mouth. In all subjects the concentrations rose in the 24 hours after ingestion. There was little change over the next nine days in the concentrations in the Europeans but those in the Asians continued to rise until about day 10. Subsequent rates of fall in 25-OHD3 were similar in the two groups. Our observations suggest that the low serum concentrations of 25-OHD3 found in Asians are not caused by either impaired intestinal absorption of vitamin D or rapid clearance of 25-ODH3 from the plasma.  相似文献   

3.
The presence of vascular calcification (VC) is a predictor of poor survival in the general population. The development of VC is an active process that requires a pre-existing injury as an inducer and promoting factors such as hyperphosphatemia and hypercalcemia, as well as a deficiency in calcification repressor factors. Vascular smooth muscle cells possess an endogenous enzyme system for the biosynthesis of the vitamin D hormone calcitriol from its precursor 25-hydroxyvitamin D and also a cytosolic calcitriol receptor, indicating that the vasculature is an important target tissue for vitamin D. The toxic effects of supra-physiological vitamin D dosages on the vasculature have been known for several decades. Recent experimental data also demonstrate important physiological effects of vitamin D on factors that are protective for vascular health. This review article summarises the molecular basis of protective and toxic vitamin D actions on the vasculature. Chronic kidney disease can be considered as a human model of severe VC and poor survival. The disease is associated with calcitriol deficiency, hyperparathyroidism, and hyperphosphatemia. Evidence is increasing that phosphate overload plays a key role in the process of VC in chronic kidney disease. The first clinical studies indicate that vitamin D receptor activation can improve survival in these patients. Although less severe than in chronic kidney disease, vitamin D deficiency and secondary hyperparathyroidism are also frequent in the general population, especially in elderly and obese subjects. Future studies should focus on the impact of vitamin D deficiency on VC and clinical outcome in these groups.  相似文献   

4.
The essentiality of vitamin D for normal growth and development has been recognized for over 80 years, and vitamin D fortification programs have been in place in the United States for more than 70 years. Despite the above, vitamin D deficiency continues to be a common finding in certain population groups. Vitamin D deficiency has been suggested as a potential risk factor for the development of preeclampsia, and vitamin D deficiency during infancy and early childhood is associated with an increased risk for numerous skeletal disorders, as well as immunological and vascular abnormalities. Vitamin D deficiency can occur through multiple mechanisms including the consumption of diets low in this vitamin and inadequate exposure to environmental ultraviolet B rays. The potential value of vitamin D supplementation in high‐risk pregnancies and during infancy and early childhood is discussed. Currently, there is vigorous debate concerning what constitutes appropriate vitamin D intakes during early development as exemplified by differing recommendations from the Institute of Medicine Dietary Reference Intake report and recent recommendations by the Endocrine Society. As is discussed, a major issue that needs to be resolved is what key biological endpoint should be used when making vitamin D recommendations for the pregnant woman and her offspring. Birth Defects Research (Part C) 99:24–44, 2013. © 2013 Wiley Periodicals, Inc.  相似文献   

5.
There is no doubt that solar ultraviolet (UV) exposure is the most important environmental risk factor for the development of non-melanoma skin cancer. Therefore, sun protection is of particular importance to prevent these malignancies, especially in risk groups. However, 90% of all requisite vitamin D has to be formed in the skin through the action of the sun-a serious problem, for a connection between vitamin D deficiency and a broad variety of independent diseases including various types of cancer, bone diseases, autoimmune diseases, hypertension and cardiovascular disease has now been clearly indicated in a large number of epidemiologic and laboratory studies. An important link that improved our understanding of these new findings was the discovery that the biologically active vitamin D metabolite 1,25(OH)(2)D is not exclusively produced in the kidney, but in many other tissues such as prostate, colon, skin and osteoblasts. Extra-renally produced 1,25(OH)(2)D is now considered to be an autocrine or paracrine hormone, regulating various cellular functions including cell growth. We and others have shown that strict sun protection causes vitamin D deficiency in risk groups. In the light of new scientific findings that convincingly demonstrate an association of vitamin D deficiency with a variety of severe diseases including various cancers, the detection and treatment of vitamin D deficiency in sun-deprived risk groups is of high importance. It has to be emphasized that in groups that are at high risk of developing vitamin D deficiency (e.g., nursing home residents or patients under immunosuppressive therapy), vitamin D status has to be monitored. Vitamin D deficiency should be treated, e.g., by giving vitamin D orally. Dermatologists and other clinicians have to recognize that there is convincing evidence that the protective effect of less intense solar UV radiation outweighs its mutagenic effects. Although further work is necessary to define an adequate vitamin D status and adequate guidelines for solar UV exposure, it is at present mandatory that public health campaigns and recommendations of dermatologists on sun protection consider these facts. Well-balanced recommendations on sun protection have to ensure an adequate vitamin D status, thereby protecting people against adverse effects of strict sun protection without significantly increasing the risk of developing UV-induced skin cancer.  相似文献   

6.
Vitamin D(3), via its active metabolite 1alpha,25-dihydroxyvitamin D(3), helps maintain normal calcium levels in the body. Apart from the maintenance of calcium homeostasis, the active form of vitamin D(3) is now known to be involved in a number of other functions including that of pancreatic beta cells. Low serum insulin levels and impaired glucose tolerance in a vitamin D-deficient state have been reported in experimental animals. Hypocalcemia is a major consequence of vitamin D deficiency. Whether the impairment observed is due to vitamin D deficiency per se or is secondary to low calcium is still a matter of controversy. The present study was conducted to delineate the roles of vitamin D and calcium in glucose intolerance associated with vitamin D deficiency in vivo. It was found that supplementation with either vitamin D(3) or high calcium alone to vitamin D-deficient rats could correct the defects. In addition, insulin sensitivity was found to be enhanced in the vitamin D-deficient group compared with vitamin D control or calcium-supplemented groups. Hence the present study demonstrates that calcium per se in the absence of vitamin D increases insulin secretion and normalizes intolerance to glucose seen in vitamin D deficiency.  相似文献   

7.
Cyclic AMP-dependent protein kinase activity in supernatants of homogenates of kidneys from vitamin D-deficient chicks is decreased to 70% of the level measured in kidneys from normal chicks. Activity was restored to normal by oral administration of vitamin D or 1,25-dihydroxyvitamin D3 for 1 or 2 weeks. Both isozymes of cAMP-dependent protein kinase were reduced to the same extent by vitamin D deficiency. The decreased enzyme activity could not be accounted for by a shift to the particulate fraction nor by an increased requirement for cyclic AMP. A heat stable, trichloroacetic acid-precipitable, trypsin-labile inhibitor of protein kinase activity was identified and quantitated in kidneys from vitamin D-deficient chicks (16 to 26 units/mg of protein) and from those given vitamin D (2 to 6 units/mg of protein). The measured difference in inhibitor levels could not be attributed to differential stability in kidney homogenates from vitamin D-deficient or -repleted chicks. The observed increase in inhibitor level with vitamin D deficiency is not sufficient to account for the decrease in cyclic AMP-dependent protein kinase activity, suggesting that the total amount of this enzyme activity is reduced in vitamin D deficiency.  相似文献   

8.
To assess the effect of religious dietary practices and social customs on the vitamin D status of Asian immigrants, we kept records of the dietary intake and time spent out of doors of 81 Ugandan Asian men, women, and girls (9-19 years old). Sera were analysed for 25-hydroxycholecalciferol (25-OHD3), and 28% of the subjects were found to have levels below the lower limit of normal. The (vegetarian) Hindus had the lowest dietary intakes, least time out of doors, and lowest serum 25-OHD3. The Goan (Roman Catholic) Asians, despite more pigmentation, had 25-OHD3 levels similar to those found among indigenous British people and had the most satisfactory vitamin D intakes. Among Asians, whose exposure to sunlight may be limited, dietary vitamin D becomes the major determinant of serum 25-OHD3.  相似文献   

9.
PURPOSE OF REVIEW: Vascular calcification is frequently found in patients with osteoporosis, atherosclerosis and chronic kidney disease, leading to high morbidity and mortality rates. The effects of vitamin D excess and deficiency on vascular calcification are reviewed in this article. RECENT FINDINGS: There is evidence from experimental studies that mediacalcinosis induced by vitamin D excess is an active and reversible process. Vitamin D excess, however, is rarely seen in the general human population. Experimental data also demonstrate that physiologic vitamin D actions include the inhibition of processes that are important for intimal and medial artery calcification such as pro-inflammatory cytokine release, adhesion molecule release, and proliferation and migration of vascular smooth muscle cells. In uremic rats, low levels of the vitamin D hormone calcitriol are associated with massive vascular and soft tissue calcifications. Whereas retrospective studies already indicate a beneficial effect of active vitamin D on mortality rates in chronic kidney disease, little is yet known about the effect of vitamin D deficiency on cardiovascular morbidity and mortality in the general population. SUMMARY: Available data indicate that vitamin D exerts a biphasic 'dose response' curve on vascular calcification with deleterious consequences not only of vitamin D excess but also of vitamin D deficiency.  相似文献   

10.

Introduction

Vitamin D deficiency is highly prevalent and is associated with bone disease, cardiovascular disease, metabolic syndrome and malignancy. Injection drug users (IDUs), with or without HIV infection, are at risk for these conditions; however, limited data on vitamin D deficiency exist in this population. We determined the prevalence and correlates of vitamin D deficiency among urban IDUs in the AIDS Linked to the IntraVenous Experience (ALIVE) Study cohort.

Methods

For this cross-sectional sub-study, vitamin D deficiency was defined as a serum 25(OH)-vitamin D level <20 ng/mL. Multivariable logistic regression was used to identify factors independently associated with vitamin D deficiency.

Results

Of 950 individuals analyzed, 29% were HIV-infected. The median age was 49 years; 65% were male, and 91% were black. The median vitamin D level was 13.5 ng/mL (IQR, 9.0–20.3); 74% were deficient (68% in HIV-infected vs. 76% in HIV-uninfected, p = 0.01). Non-black race, fall/winter season, multivitamin intake, higher serum albumin, HCV seropositivity and HIV-infection were associated with significantly lower odds of vitamin D deficiency.

Conclusions

Vitamin D deficiency is prevalent among IDUs. Notably, HIV-infected IDUs were less likely to be vitamin D deficient. Higher vitamin D levels were associated with multivitamin intake and with higher albumin levels, suggesting that nutritional status contributes substantially to deficiency. The association between HCV serostatus and vitamin D level remains unclear. Further investigation is needed to define the clinical implications of the heavy burden of vitamin D deficiency in this high-risk, aging population with significant co-morbidities.  相似文献   

11.

Background

Recent studies have shown that inadequate vitamin D levels are associated with a poor cancer prognosis, but data regarding actual vitamin D levels in cancer survivors are limited. This study investigated the vitamin D levels and prevalence of vitamin D deficiency among Korean cancer survivors compared with non-cancer controls, and identified the factors associated with vitamin D deficiency.

Methods

Using the Korea National Health and Nutrition Examination Survey (KNHANES), 915 cancer survivors and 29,694 controls without a history of cancer were selected. Serum 25(OH)D levels were measured; vitamin D deficiency was defined as 25(OH)D levels less than 20 ng/mL. Chi-square tests and multiple logistic regression analyses were used to evaluate the prevalence of vitamin D deficiency and associated factors.

Results

Vitamin D deficiency was observed in 62.7% of cancer survivors and 67.1% of controls. Among cancer survivors, vitamin D deficiency was most prevalent among 19–44 year olds (76.2%) and among managers, professionals, and related workers (79.3%). Multiple logistic regression analysis revealed that younger cancer survivors and those who work indoors were predisposed to vitamin D deficiency.

Conclusion

Vitamin D deficiency was prevalent among both cancer survivors and controls in Korea. The regular evaluation and management of vitamin D levels is needed for both bone health and general health in cancer survivors.  相似文献   

12.
Epidemiological evidence indicates a significant association between vitamin D deficiency and an increased incidence of autoimmune diseases. The presence of vitamin D receptors in the cells of the immune system and the fact that several of these cells produce the vitamin D hormone suggested that vitamin D could have immunoregulatory properties, and now potent immuno-mudulatory activities on dendritic cells, Th1 and Th17 cells, as well as B cells have been confirmed. Patients with undifferentiated connective tissue disease also show vitamin D deficiency and, interestingly, patients who progress into connective tissue diseases have lower vitamin D levels than those who remain in the undifferentiated connective tissue disease stage.  相似文献   

13.
The vitamin D and K deficiency was studied for its effect on creatine kinase, phosphorylase and alkaline phosphatase activity of rat kidneys and intestinal mucosa. The results show that creatine kinase and phosphorylase activity of kidneys varies depending on the content of these vitamins, e.g. it is activated with vitamin D depletion irrespective of the vitamin K status and remains unchanged with the deficiency of vitamin K alone. In this case the vitamin D deficiency affects kidney phosphorylase and intestinal mucosa differently. Data obtained and those available in literature permit suggesting that the deficiency of the same vitamin may exert a different action on the activity of isoforms of such enzymes as creatine kinase and phosphorylase.  相似文献   

14.
《Endocrine practice》2015,21(7):761-769
Objective: Vitamin D deficiency is prevalent in cirrhotic patients awaiting liver transplantation (LT). Optimal vitamin D management for these patients remains undefined. We sought to determine the effectiveness of our practice in addressing vitamin D deficiency in LT patients.Methods: This retrospective study included 127 patients who received a first LT between July 2010 and July 2011. Outcomes measured included readmission rates, fractures, and functional status post-LT. 25-Hydroxyvitamin D (25-OH D) deficiency was stratified as: mild (20–30 ng/mL), moderate (15–19.9 ng/mL), and severe (<15 ng/mL). We estimated the amount of vitamin D supplementation required for each patient.Results: At LT evaluation, 107 patients (84%) had vitamin D deficiency, and 74% remained vitamin D deficient at LT. Only 62% received vitamin D supplementation pre-LT. Moderate and severe deficiencies were less common at LT and rare 4 months post-LT. There was an association between improvement in vitamin D deficiency category at LT and increased vitamin D (>400,000 IU total) supplementation (P = .004). We found no association between vitamin D deficiency at LT and functional status, fractures, or readmissions post-LT. Patients receiving induction immunosuppressant therapy with basiliximab had a significantly greater degree of worsening in bone mineral density (BMD) post-LT.Conclusion: Moderate-to-severe vitamin D deficiency was very prevalent in a cohort of patients undergoing evaluation for LT. Deficiency was improved with increased vitamin D replacement therapy. Vitamin D deficiency at LT was not associated with worse bone or functional outcomes post-LT. The influence of basiliximab on bone health post-LT requires further evaluation.Abbreviations: 25-OH D = 25-hydroxyvitamin D BMD = bone mineral density BMI = body mass index CI = confidence interval LT = liver transplantation MELD = Model for End-Stage Liver Disease PTH = parathyroid hormone  相似文献   

15.
The mechanism(s) by which vitamin D(3) regulates female reproduction is minimally understood. We tested the hypothesis that peripubertal vitamin D(3) deficiency disrupts hypothalamic-pituitary-ovarian physiology. To test this hypothesis, we used wild-type mice and Cyp27b1 (the rate-limiting enzyme in the synthesis of 1,25-dihydroxyvitamin D(3)) null mice to study the effect of vitamin D(3) deficiency on puberty and reproductive physiology. At the time of weaning, mice were randomized to a vitamin D(3)-replete or -deficient diet supplemented with calcium. We assessed the age of vaginal opening and first estrus (puberty markers), gonadotropin levels, ovarian histology, ovarian responsiveness to exogenous gonadotropins, and estrous cyclicity. Peripubertal vitamin D(3) deficiency significantly delayed vaginal opening without affecting the number of GnRH-immunopositive neurons or estradiol-negative feedback on gonadotropin levels during diestrus. Young adult females maintained on a vitamin D(3)-deficient diet after puberty had arrested follicular development and prolonged estrous cycles characterized by extended periods of diestrus. Ovaries of vitamin D(3)-deficient Cyp27b1 null mice responded to exogenous gonadotropins and deposited significantly more oocytes into the oviducts than mice maintained on a vitamin D(3)-replete diet. Estrous cycles were restored when vitamin D(3)-deficient Cyp27b1 null young adult females were transferred to a vitamin D(3)-replete diet. This study is the first to demonstrate that peripubertal vitamin D(3) sufficiency is important for an appropriately timed pubertal transition and maintenance of normal female reproductive physiology. These data suggest vitamin D(3) is a key regulator of neuroendocrine and ovarian physiology.  相似文献   

16.
A connection between vitamin D deficiency and severe health problems including various types of cancer has been demonstrated. We have shown that patients that have to protect themselves against solar UV radiation for medical reasons, including patients with xeroderma pigmentosum (XP), basal cell nevus syndrome (BCNS), lupus erythematodes (LE) or transplant recipients, are at risk to develop vitamin D deficiency. We conclude that 25-hydroxyvitamin D serum levels as a measure of vitamin D status have to be analyzed in patients that have to protect themselves against solar UV radiation for medical reasons. Suboptimal vitamin D status has to be substituted (e.g. via oral treatment) to protect against serious vitamin D deficiency-related health problems without increasing the risk to develop solar UV-induced skin cancer. Our finding that protection against solar UV radiation causes vitamin D deficiency underlines the need for re-defining dermatological recommendations for solar UV protection in skin cancer prevention programs.  相似文献   

17.
《Endocrine practice》2020,26(10):1062-1069
Objective: Subacute thyroiditis (SAT) is an inflammatory thyroid disease that manifests with severe pain. The presence of the vitamin D receptor in immune system cells shows that vitamin D deficiency can trigger inflammatory diseases. The aim of the present study was to determine the prevalence of vitamin D deficiency in SAT patients, and the relationship between vitamin D level and permanent hypothyroidism and recurrence rate.Methods: In this retrospective study, 25-hydroxyvitamin D (25&lsqb;OH]D) levels of 170 SAT patients and 86 control subjects were compared.Results: The 25(OH)D levels were significantly lower in the SAT patients, and there was no seasonal difference. A negative correlation was determined between the erythrocyte sedimentation rate and 25(OH)D, but no significant relationship was found between vitamin D level and prognosis.Conclusion: As a result of this study, it was shown that vitamin D levels in subacute thyroiditis patients were significantly lower than in the healthy control group. Although there is no relationship between vitamin D level and disease prognosis, vitamin D deficiency may increase the rate of respiratory tract infections (especially, influenza, coxsackievirus, measles, adenovirus, retroviruses) and eventually SAT development.  相似文献   

18.
An increasing number of studies suggest that vitamin D deficiency during pregnancy is associated with multiple adverse health outcomes in mothers, neonates and children. There are no representative country data available on vitamin D status of pregnant women in Europe. The aim of this study was to estimate the prevalence of vitamin D deficiency among Belgian pregnant women and to assess the determinants of vitamin D status in the first and third trimester of pregnancy. The women were selected via a multi-stage proportionate-to-size sampling design. Blood samples were collected and a questionnaire was completed face-to-face. 55 obstetric clinics were randomly selected and 1311 pregnant women participated in the study. The median serum 25-hydroxyvitamin D [25-(OH)D] concentration was significantly lower in the first trimester (20.4 ng/ml) than in third trimester (22.7 ng/ml). Of all women, 74.1% (95%CI = 71.8–76.5%) were vitamin D insufficient (25-(OH)D <30 ng/ml), 44.6% (95%CI = 41.9–47.3%) were vitamin D deficient (25-(OH)D <20 ng/ml), while 12.1% (95%CI = 10.3–13.8%) were severely vitamin D deficient (25-(OH)D <10 ng/ml). Of all women included, 62.0% reported taking vitamin D-containing multivitamins, of which only 24.2% started taking those before pregnancy. The risk of vitamin D deficiency (25-(OH)D <20 ng/ml) was significantly higher for less educated women and women who reported not going on holidays to sunny climates. The risk of severe vitamin D deficiency (25-(OH)D <10 ng/ml) decreased for women who reported alcohol consumption during pregnancy, decreased with more frequent use of sunscreen lotion and increased for smokers and women who reported preference for shadow. In conclusion, vitamin D deficiency is highly prevalent among pregnant women in Belgium and this raises concerns about the health consequences for the mother and the offspring. A targeted screening strategy to detect and treat women at high risk of severe vitamin D deficiency is needed in Belgium and in Europe.  相似文献   

19.
There is a growing number of diseases which prevalence can be associated with vitamin D deficiency. The link between low cholecalciferol concentration and bone diseases is well established, however there is also data suggesting that it may influence development and progression of different cancers and autoimmune diseases. The in vitro studies proved that the active vitamin D metabolite--1,25(OH)(2)D(3) may arrest the cell cycle progression, induce apoptosis as well as regulate T cells and antigen presenting cells function. Results of the in vivo experiments suggest that vitamin D deficiency accelerates development of autoimmune diseases and cancers in animals. Epidemiological studies imply that the vitamin D deficiency is also associated with the increased incidence of autoimmune diseases and cancers in people. The main determinant of vitamin D serum concentration in a human body is skin synthesis. The changes in the lifestyle, air pollution as well as a common use of sun screens caused that the contemporary European receives little sunlight compared to his ancestors. According to the recent epidemiological studies, the vitamin D concentrations in serum of people who live in high latitudes (above 34 degrees N/S), including Poland, is far from being sufficient. This paper reviews results of the recent studies concerning the potential role of the vitamin D in the development of cancers and autoimmune diseases, as well as provides guidelines for vitamin D supplementation.  相似文献   

20.

Introduction

31–77% of patients with COPD have vitamin D deficiency and insufficiency, with results being highly variable between studies. Vitamin D may also correlate with disease characteristics.

Aim

To find out the prevalence of vitamin D deficiency and insufficiency in patients with COPD admitted for exacerbation and a risk factors for lower vitamin D levels among comorbidities and COPD characteristics.

Methods

152 patients were studied for vitamin D serum levels (25(OH)D). All of them were also assessed for diabetes mellitus (DM) and metabolic syndrome (MS). Data were gathered also for smoking status and exacerbations in last year. All patients completed CAT and mMRC questionnaires and underwent spirometry.

Results

A total of 83,6% of patients have reduced levels of vitamin D. 42,8% (65/152) have vitamin D insufficiency (defined as 25–50 nmol/L) and 40,8% (62/152) have vitamin D deficiency (<25 nmol/L). The mean level of 25(OH)D for all patients is 31,97 nmol/L (95%CI 29,12–34,68). Vitamin D deficiency and insufficiency are more prevalent in females vs. males (97,7 vs 77,8%; p = 0.003). The prevalence and severity of vitamin D deficiency and insufficiency in this study is significantly higher when compared to an unselected Bulgarian population (prevalence 75,8%; mean level 38,75 nmol/L). Vitamin D levels correlate with quality of life (measured by the mMRC scale) and lung function (FVC, FEV1, FEV6, FEF2575, FEV3, but not with FEV1/FVC ratio and PEF), it does not correlate with the presence of arterial hypertension, DM, MS and number of moderate, severe and total exacerbations. Vitamin D deficiency is a risk factor for longer hospital stay.

Conclusions

The patients with COPD admitted for exacerbation are a risk group for vitamin D deficiency and insufficiency, which is associated with worse disease characteristics.  相似文献   

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