Is Vitamin D the Fountain of Youth?

ObjectiveTo review the role of vitamin D deficiency for both classic and “nonclassic” effects and raise the caution that association does not prove causation.MethodsThe pertinent literature regarding vitamin D and its effects on bone, muscle function, immune function, glucose tolerance, cancer risk, and development of cardiovascular disease and other conditions is reviewed. In addition, the limitations of observational studies are discussed.ResultsVitamin D inadequacy is common worldwide and classically causes osteomalacia and rickets. More recently, the contribution of low vitamin D status to increased falls and fracture risk has become appreciated. Additionally, nonclassic effects of vitamin D inadequacy are being recognized, and low vitamin D status is being potentially associated with a multitude of conditions (including Alzheimer disease, osteoarthritis, multiple sclerosis, and hypertension) and higher overall mortality. It is important to recognize that associations in observational studies can be due to chance, bias, or confounders or may be indicative of causality.ConclusionBecause vitamin D deficiency has been established to have adverse musculoskeletal consequences, optimization of vitamin D status, for both the individual patient and the overall population, is indicated. (Endocr Pract. 2009;15:590-596)     

Primary Hyperparathyroidism and Vitamin D In African Americans

ObjectivesVitamin D deficiency is more common in African Americans than in the general population or other ethnicities. Vitamin D deficiency also occurs more frequently in patients with primary hyperparathyroidism (PHPT) than in the general population. Currently, the limited data on vitamin D deficiency in African Americans with primary hyperparathyroidism (PHPT) is inconsistent as to whether the vitamin D deficiency observed in PHPT is yet even more pronounced in Africans with PHPT relative to non-African Americans with PHPT.MethodsOn the basis of biochemical, radiological, and surgical (adenoma weight) parameters, African Americans have been reported to have a more severe form of PHPT than non-African Americans. However, comparative clinical manifestations of PHPT in African Americans have not been well described.ResultsCurrent guidelines recommend vitamin D repletion in mild, asymptomatic PHPT when levels of 25-hydroxyvitamin D are less than 20 ng/mL. Studies that reported vitamin D repletion with ergocalciferol or cholecalciferol in PHPT have not stratified data according to ethnicity. Discrepancies therefore exist between repleting vitamin D in African Americans who may potentially have a more severe PHPT profile, but simultaneously a more pronounced vitamin D deficiency.ConclusionEffectively designed clinical trials are necessary to evaluate the indications, efficacy, and safety of vitamin D in African Americans with PHPT. (Endocr Pract. 2012;18:947-953)     

Vitamin D Role and Use in Prediabetes

ObjectiveTo review the role of vitamin D in prediabetes on the basis of evidence from human studies.MethodsEnglish-language literature in MEDLINE (January 1969-July 2009) was searched for observational studies and randomized controlled trials of vitamin D deficiency and treatment in prediabetes, including impaired fasting glucose, impaired glucose tolerance, and metabolic syndrome. Search terms included hyperglycemia, glucose, glycohemoglobin, insulin resistance, diabetes, homeostasis model assessment, insulin secretion, vitamin D, and related terms. Publications were also identified from review articles and references in the found articles. Abstracts, conference proceedings, case reports, and letters were excluded. Articles concerning only type 1 and type 2 diabetes, hemodialysis, or hyperparathyroidism and studies in children were also excluded.ResultsVitamin D insufficiency is defined by a circulating 25-hydroxyvitamin D concentration less than 30 ng/mL, and it is prevalent in the United States (77% of the population). Most cross-sectional and prospective studies in various populations show inverse association between circulating 25-hydroxyvitamin D and fasting plasma glucose, impaired glucose tolerance, hemoglobin A_1c, metabolic syndrome, and incidence of prediabetes. A few clinical trials suggest beneficial effect of vitamin D supplementation in prediabetes, including improved insulin secretion, basal fasting insulin sensitivity, and postprandial peripheral insulin resistance. The limitations of the studies are small sample size, short duration of follow-up, lack of control groups, and inability to achieve vitamin D sufficiency with treatment.ConclusionAvailable data suggest that achieving vitamin D sufficiency may be beneficial in patients with prediabetes, although clinical trials are needed to provide evidence-based recommendations. (Endocr Pract. 2010;16:476-485)     

Severe Vitamin D Deficiency in Arab-American Women Living in Dearborn,Michigan

ObjectiveTo determine the prevalence and degree of 25-hydroxyvitamin D deficiency in a group of Arab- American women in the largest, most-concentrated Arab- American settlement in the United States and to search for correlations with dress, diet, and use of vitamin D–fortified foods and vitamin supplements.MethodsIn this cross-sectional study, Arab-American women, 18 years and older, who attended an ethnic market on April 7 or 14, 2007, were recruited. Participants were interviewed by bilingual English- and Arabic-speaking investigators using a semi-structured interview to assess dress; demographic variables; medical history; medication use; clinical symptoms associated with vitamin D deficiency (eg, joint or bone pain, muscle weakness); and dietary intake of vitamin D from fortified orange juice, milk, and vitamin supplementation. Blood samples were drawn to measure concentrations of serum calcium, creatinine, phosphorus, alkaline phosphatase, parathyroid hormone, and 25-hydroxyvitamin D. Participants were initially divided into 2 groups based on whether the woman was veiled and further subdivided into 3 groups on the basis of vitamin D intake from supplemented food sources (milk or vitamin D–fortified orange juice) and vitamin pills: unveiled, veiled and taking supplements, and veiled and taking no supplements.ResultsEighty-seven women participated. Serum 25-hydroxyvitamin D levels were uniformly low, with the highest levels in the unveiled group (median [interquartile range]) (8.5 ng/mL [5.75-13.5 ng/mL]) followed by the veiled, supplemented group (7 ng/mL [4-11.5 ng/mL]) and the veiled, unsupplemented group (4 ng/mL [2-6.8 ng/ mL]). 25-Hydroxyvitamin D levels were lower in women with less experience in the United States and in those with less education. Vitamin D–fortified orange juice consumption had a greater positive predictive effect on serum 25- hydroxyvitamin D levels than either milk or vitamin pills and may possibly serve as a surrogate marker for vitamin D awareness.ConclusionsVitamin D deficiency, as assessed by 25-hydroxyvitamin D concentrations, is endemic in a sample of Arab-American women living in Dearborn, Michigan. These findings potentially identify an important health problem in the largest, most-concentrated Arab- American population in the United States. (Endocr Pract. 2009;15:35-40)     

Effectiveness and Outcomes of Current Practice in Treating Vitamin D Deficiency in Patients Listed for Liver Transplantation

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     

Ethnicity,Clothing Style,and Body Mass Index are Significant Predictors of Vitamin D Insufficiency in Germany

ObjectiveTo analyze risk factors for vitamin D insufficiency in Germany with respect to ethnicity, sex, and clothing style.MethodsWe analyzed the routine diagnostic workups of 1,231 adult (45.9 ± 17.9 years old) German (n = 1,034) and Turk residents (n = 197) referred with nonspecific symptoms to the Thyroid Centers at St. Elisabeth-Hospital in Dorsten, Germany and Bottrop, Germany to assess for metabolic diseases. All subjects underwent a routine examination that consisted of a questionnaire, lab tests for 25-hydroxyvitamin-D (25OHD), and thyroid profile. Turk females with traditional clothing (headscarf and covered legs and arms) were considered to wear “covered clothing.” Logistic-regression was performed to identify factors that could predict vitamin D deficiency (< 20 ng/ mL) and insufficiency (20-30 ng/mL).ResultsVitamin D insufficiency was seen in 33% of Germans and 74.1% of Turks, and vitamin D deficiency was present in 11.3% and 44.2% of Germans and Turks, respectively (P < .001). The mean 25OHD value in Turk females with covered clothes was lower than that in Turk females with conventional clothing (16.3 ± 12.3 vs. 27.2 ± 15.8, P < .001). Vitamin D insufficiency was present in 86.0% of Turk females with covered clothing versus 62.8% with conventional clothing (odds ratio [OR] = 3.6, P = .002). Ethnicity, body mass index (BMI), and clothing style were significant predictors of vitamin D deficiency and insufficiency by logistic regression (P < .001).Conclusions(1) Vitamin D insufficiency among Turk residents in Germany is higher compared to Germans. The highest prevalence was present in Turk females with covered clothing. (2) Monitoring vitamin D in Turk residents in Germany is warranted. (3) Vitamin D supplements and access to facilities with sunlight exposure for females with covered clothing and all individuals with poor diets or limited access to sun exposure may prevent future health burden due to vitamin D insufficiency. (Endocr Pract. 2015; 21:122-127)     

Low Maternal Vitamin D Status during the Second Trimester of Pregnancy: A Cross-Sectional Study in Wuxi,China

BackgroundVitamin D deficiency is common in pregnant women, but an optimal serum vitamin D level during pregnancy has not been determined and remains an area of active research. Vitamin D data from large populations of pregnant Chinese women are still limited.ObjectiveTo evaluate the vitamin D status of women in Eastern China during the second trimester of pregnancy.MethodsA hospital-based, cross-sectional, observational study. Serum 25-hydroxyvitamin D [25(OH)D] concentration was measured in samples from 5823 pregnant women in Wuxi City, China (latitude: 31.5o N), from January 2011 to June 2012.ResultsThe median serum 25(OH)D concentration was 34.0 nmol/L [2.5 nmol/L 25(OH)D = 1 ng/mL 25(OH)D]. Vitamin D deficiency [defined as 25(OH)D < 30 nmol/L according to the Institute of Medicine (National Academy of Sciences, Washington, D.C., USA)] or inadequacy [25(OH)D of 30–49.9 nmol/L] was identified in 40.7% and 38.0% of the women, respectively. Only 0.9% had a 25(OH)D level ≥ 80.0 nmol/L, which is the concentration recommended as adequate by the Endocrine Society (Washington, D.C., USA). Compared with older women, younger women were more likely to be deficient in vitamin D. There were significant differences in the 25(OH)D levels according to season. The 25(OH)D levels reached peak values in September and were correlated with (r = 0.337, P < 0.001), and fluctuated with, average monthly air temperatures.ConclusionsThere is a high prevalence of Vitamin D deficiency among pregnant Chinese women, and 25(OH)D levels varied according to season and air temperature. The results of this study also suggest that currently there is a big gap between the levels of Vitamin D detected in pregnant Chinese women and the levels recommended by the Endocrine Society.     

The Association of Vitamin D Receptor Polymorphisms with Multiple Sclerosis in a Case-Control Study from Kuwait

Vitamin D deficiency is associated with several diseases including multiple sclerosis (MS). Several factors influence vitamin D levels and its optimal multi-function maintenance. Our objective was to assess quantifiable variables influencing vitamin D level and metabolism in MS patients from Kuwait. In a case-control study involving 50 MS patients, and 50 healthy control individuals for which plasma vitamin D levels, supplement use, vitamin D receptor (VDR) variants, and skin pigmentation indices were ascertained; we found overall vitamin D levels to be deficient in both groups, and supplement use to be common practice. VDR variants TaqI and BsmI associated with MS risk, and ApaI associated with low disease progression. VDR variant FokI associated with higher vitamin D levels in both groups. We conclude that several quantifiable variables related to vitamin D associate with MS suggesting a possible clinical immuno-modulatory application of vitamin D for MS patients in Kuwait.     

Hypovitaminosis D and Bone Mineral Density in Human Immunodeficiency Virus-Infected Men from India,with or without Antiretroviral Therapy

ObjectiveTo study the vitamin D status and bone mineral density (BMD) in men infected with human immunodeficiency virus (HIV) in a tertiary care center from southern India.MethodsWe conducted a cross-sectional study of 35 HIV-infected men (between 20 and 50 years old) receiving highly active antiretroviral therapy (HAART) (group 1) in comparison with 35 ageand body mass index-matched HIV-positive antiretroviral therapy-naïve men (group 2) and 35 HIV-negative healthy control subjects (group 3).ResultsA significantly greater proportion (P = .002) of patients (74%) in the HAART group had vitamin D deficiency (< 20 ng/mL) in comparison with the other 2 groups (37% in each group). The mean intact parathyroid hormone level was higher (P < .001) and the mean duration of exposure to sunlight was lower (P = .001) in the HAART group than in the other 2 groups. By logistic regression analysis, HAART was found to be significantly associated with vitamin D deficiency. The BMD in the femoral neck was significantly lower in men with HIV infection who were receiving HAART in comparison with the other 2 groups (P = .006). On multivariate logistic regression, older age, low body mass index, and high parathyroid hormone levels emerged as factors significantly associated with decreased BMD at the femoral neck.ConclusionA significant proportion of patients receiving HAART had vitamin D deficiency. The secondary hyperparathyroidism probably due to vitamin D deficiency is an important contributing factor for the observed changes in BMD. Vitamin D deficiency noted in this group is probably multifactorial, and further research is needed to determine whether the effect of HAART on vitamin D metabolism is an additional causative factor and what benefit vitamin D supplementation might confer in these patients. (Endocr Pract. 2010;16:547-553)     

Vitamin D in healthy Tunisian population: Preliminary results

BackgroundVitamin D deficiency is one of the most common medical conditions worldwide. In Tunisia, several studies evaluated Vitamin D status, but this was concerning specific populations (pregnant women, obese or diabetic patients and children with asthma). The only study that evaluated Vitamin D status in a healthy Tunisian population was conducted by Meddeb and associeties in 2002. The update of data available, based on the currently recommended limits, is necessary. This study aimed to estimate the prevalence of hypovitaminosis D in a healthy Tunisian population, and correlate the values with potential risk factors.MethodsIt was conducted on 209 Tunisian healthy subjects. Data collected included clinical characteristics and dietary intakes. We measured 25-hydroxyvitamin D (25(OH)D), parathyroid hormone (PTH), glycemia, creatinine, calcium, phosphorus, and alkaline phosphatase concentrations. Hypovitaminosis D was retained for 25(OH)D concentrations <75 nmol/L. Vitamin D deficiency was defined by 25(OH)D concentrations <25 nmol/L.ResultsThe prevalence of hypovitaminosis D and vitamin D deficiency were respectively 92.3% and 47.6%. The main factors that were significantly associated with low vitamin D levels in our multivariate analysis were veiling, living in rural areas and sunscreen use. However, sex, age, socioeconomic level, phototype, solar exposure score, smoking and bone mass index, were not statistically associated with hypovitaminosis D. The study of relationship between vitamin D status and serum PTH levels showed a significative and negative correlation (P < 0.005).ConclusionsGiven the high prevalence of vitamin D, an adapted health policy is essential. A widespread vitamin D supplementation and food fortification seems to be necessary in Tunisia.     

Vitamin D Binding Protein Gene Polymorphism as a Risk Factor for Vitamin D Deficiency in Thais

ObjectiveVitamin D deficiency is related to increased risks for a number of diseases. To date, at least 3 candidate genes, vitamin D binding protein (VDBP) gene (GC), 25-hydroxylase (CYP2R1), and 7-dehydrocholes-terol reductase/NAD synthetase 1 (DHCR7/NADSYN1), have been associated with serum 25-hydroxyvitamin D (25[OH]D) levels, but their influences on the prevalence of vitamin D deficiency in relation to other known risk factors have not been clearly defined.MethodsThe study assessed 4,476 individuals aged 14 to 93 years from the Thailand 4^th National Health Examination Survey (2008-2009) and the Electricity Generating Authority of Thailand (EGAT) (2008) cohorts. The GC rs2282679 polymorphism on chromosome 4q12-q13 was genotyped by real-time polymerase chain reaction (PCR). Serum 25(OH)D was measured by liquid chromatography/tandem mass spectrometry. Vitamin D deficiency was defined as a 25(OH)D concentration < 20 ng/mL.ResultsData were expressed as mean ± SD. There were 2,747 (61.4%) males and 1,729 (38.6%) females in the study, with an average body mass index (BMI) of 23.7 ± 4.2 kg/m² and a mean total 25(OH)D of 28.9 ± 9.0 ng/mL. Serum 25(OH)D levels decreased progressively with the presence of the C allele. Using multiple logistic regression analysis, vitamin D deficiency was significantly associated with the GC rs2282679 genotype (odds ratio [OR] per C allele 1.80, 95% confidence interval CI 1.57-2.01), independent of established risk factors for vitamin D deficiency including age, sex, and BMI.ConclusionA specific GC gene polymorphism is associated with lower 25(OH)D levels independent of age, sex, and adiposity in Thai subjects. (Endocr Pract. 2015;21:221-225)     

The Prevalence of Vitamin D Deficiency among Cancer Survivors in a Nationwide Survey of the Korean Population

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.     

Low Vitamin D Status is Associated with Increased Thyrotropin-Receptor Antibody Titer in Graves Disease

ObjectiveVitamin D deficiency is reportedly linked to a variety of autoimmune diseases. However, the relationship between thyroid autoimmunity in Graves disease (GD) and vitamin D deficiency is unclear. The goal of this study was to determine whether increased thyroid hormone autoantibody titer is associated with vitamin D deficiency in GD patients.MethodsA total of 70 patients with GD and 70 matched control subjects were recruited to our study. The levels of 25-hydroxyvitamin D (25[OH]D), calcium, parathyroid hormone (PTH), free triiodothyronine (FT₃), free thyroxine (FT₄), thyroid-stimulating hormone (TSH), thyrotropin-receptor antibody (TRAb), thyroid-peroxidase antibody (TPOAb), and thyroglobulin antibody (TGAb) in serum collected from these patients and controls were examined.ResultsThe level of 25(OH)D in serum from TRAb-positive GD patients was significantly lower than that in serum of healthy controls or TRAb-negative patients. However, compared with control subjects, the level of PTH in serum was increased in TRAb-positive GD patients. The rate of vitamin D deficiency (defined as serum 25[OH]D < 50 nmol/L) in TRAb-positive GD patients was significantly higher than in healthy controls or TRAb-negative GD patients. The level of 25(OH)D in serum was inversely correlated with TRAb titer in serum of TRAb-positive GD patients. However, our results did not show a correlation between 25(OH)D level and the levels of TPOAb, TGAb, FT₃, FT₄, or TSH.ConclusionLow vitamin D status is associated with increased TRAb titer in GD, suggesting a possible link between vitamin D status and increased thyroid autoim-munity in GD patients. (Endocr Pract. 2015;21:258-263)     

Hashimoto Thyroiditis not Associated with Vitamin D Deficiency

Objective: Vitamin D deficiency is associated with several autoimmune diseases. This study assessed whether vitamin D deficiency is associated with Hashimoto thyroiditis (HT).Methods: Two groups of patients were selected for which serum 25-hydroxyvitamin D (25(OH)D) levels had been measured: (1) a study group of patients diagnosed with HT as indicated by thyroid antibodies, and (2) a healthy control group. Each group was separated by sex and then controlled for age and body mass index (BMI). Groups' mean 25(OH)D levels were compared by analysis of variance (ANOVA), and percent frequencies of vitamin D sufficiency, insufficiency, and deficiency were compared with a Z-test. The correlations between 25(OH)D levels and thyroid antibodies and thyroid-stimulating hormone (TSH) levels were also tested.Results: The mean 25(OH)D levels for the HT and control groups were significantly different in females (30.75 vs. 27.56 ng/mL, respectively) but not in males (14.24 vs. 13.26 ng/mL). HT females had a higher rate of vitamin D sufficiency (51.7% vs. 31.1%) and a lower rate of insufficiency (48.3% vs. 68.9%) relative to control females. No such differences were found in the male groups. None of the females were vitamin D deficient, but almost all males were. A significant (P = .016) positive correlation (r_s = 0.436) between 25(OH)D and TPOAb was observed in males.Conclusion: HT is not associated with higher rates of vitamin D deficiency relative to a control group.Abbreviations:BMI = body mass indexHT = Hashimoto thyroiditis25(OH)D = 25-hydroxyvitamin DTgAb = thyroglobulin antibodyTSH = thyroid-stimulating hormoneTPOAb = thyroid-peroxidase antibodyVDR = Vitamin D receptor     

Effect of Vitamin D Therapy on Bone Turnover Markers in Postmenopausal Women with Osteoporosis and Osteopenia

ObjectiveTo (7) assess the rate of reduction in bone turnover with vitamin D and bisphosphonate therapies and (2) evaluate the clinical utility of bone-specific alkaline phosphatase (BSAP) in monitoring treatment response.MethodsWe retrospectively reviewed medical records of patients with newly diagnosed osteopenia and osteoporosis from 2002 to 2009 at Loyola University Medical Center. A cohort of postmenopausal women with hip or spine T-scores of less than -1, normal serum creatinine, and no prior vitamin D or bisphosphonate therapy was divided into vitamin D-deficient (n = 29) and vitamin D-sufficient (n = 13) groups. Vitamin D-deficient patients received high-dose vitamin D, whereas vitamin D-sufficient patients received orally administered bisphosphonates. BSAP levels at baseline and 1 year were compared.Resultsvitamin D therapy in the group with vitamin D deficiency led to a 26.7% decrease in BSAP (P < .01). Bisphosphonate therapy in the vitamin D-sufficient group led to a 32.7% decrease in BSAP (P = .01). The magnitude of BSAP change in the 2 study groups (6.74 ± 6.48 μg ∕ L and 8.72 ± 9.94 μgZL) did not differ significantly (P = .45).ConclusionThe results of this study suggest that correction of vitamin D deficiency in patients with osteopenia and osteoporosis can lead to a decrease in bone turnover as measured by BSAP and that the magnitude of this reduction is similar to that achieved with orally administered bisphosphonates. (Endocr Pract. 2011;17:873-879)     

Vitamin D attenuates inflammation,fatty infiltration,and cartilage loss in the knee of hyperlipidemic microswine

BackgroundOsteoarthritis (OA) of the knee joint is a degenerative process resulting in cartilage loss. Recent evidence suggests that OA is not merely a disease of cartilage but a disease of the entire knee joint and that inflammation may play an important role. OA has been associated with vitamin D deficiency. Vitamin D as an immunomodulator and anti-inflammatory agent may attenuate inflammation in the knee. The aim of this study was to assess the anti-inflammatory effect of vitamin D on inflammation in the knee.MethodsThis study was conducted with 13 microswine on a high cholesterol diet categorized into three groups of vitamin D-deficient, vitamin D-sufficient, and vitamin D supplementation. After 1 year, microswine were killed, and their knee joint tissues were harvested. Histological and immunofluorescence studies were carried out on the tissue specimens to evaluate the effect of vitamin D status.ResultsHistological and immunofluorescence studies of the knee joint tissues showed (1) increased inflammation in the knee joint tissues, (2) fatty infiltration in quadriceps muscle, patellar tendon, and collateral ligaments, and (3) chondrocyte clustering in the vitamin D-deficient and vitamin D-sufficient groups compared with the vitamin D supplementation group. Architectural distortion of the quadriceps muscle, patellar tendon, and collateral ligaments was also seen in the areas of inflammatory foci and fatty infiltration in the vitamin D-deficient group.ConclusionsDecreased inflammation and fatty infiltration in the vitamin D supplementation group suggest the potential role of vitamin D in attenuating inflammation and fatty infiltration as well as in protecting the architecture of the tissue in the knee joint.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-016-1099-6) contains supplementary material, which is available to authorized users.     

Vitamin D Deficiency and Insufficiency in Hospitalized COPD Patients

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.     

Vitamin D Deficiency Among Medical Residents and Its Relationship with Metabolic Indices

ObjectiveTo evaluate different elements of the cal- ciotropic system in a group of house staff physicians, comparing them with age, gender, and body mass index (BMI) matched controls.MethodsWe measured vitamin D, calcium, phosphorus, parathyroid hormone (PTH), glucose, insulin (estimating the insulin resistance index by the homeostatic model [HOMA]), and lipid levels in 20 medical residents and 20 age-, gender-, and BMI-matched controls. We looked for correlations between elements of the calciotropic system and metabolic indices.ResultsMedical residents and controls were similar in regard to gender distribution, weight, height, BMI, abdominal circumference, as well as systolic and diastolic blood pressure. No differences were found between the two groups in regard to low-density lipoprotein (LDL)-cholesterol, high-density lipoprotein (HDL)-cholesterol, plasma insulin levels, and HOMA-IR. Vitamin D and calcium levels were significantly lower among the medical residents (P = .001 and P = .003, respectively), whereas PTH concentrations tended to be higher. We found an inverse correlation between triglyceride concentrations and vitamin D (r = −0.31, P = .04).ConclusionVitamin D deficiency among resident physicians is frequent and could have metabolic effects. Our findings highlight the consequences of the lack of sun exposure due to occupational reasons. We recommend a higher intake of vitamin D during this period. (Endocr Pract. 2013;19:59-63)     

Vitamin D for Treatment and Prevention of Infectious Diseases; A Systematic Review of Randomized Controlled Trials

ObjectiveTo review the existing human controlled intervention studies of vitamin D as adjunctive therapy in settings of infection and provide recommendations for design and implementation of future studies in this field on the basis of the evidence reviewed.MethodsWe conducted a systematic review of randomized controlled clinical trials that studied vitamin D for treatment or prevention of infectious diseases in humans. Studies from 1948 through 2009 were identified through search terms in PubMed and Ovid MEDLINE.ResultsThirteen published controlled trials were identified by our search criteria. Ten trials were placebo controlled, and 9 of the 10 were conducted in a rigorous double-blind design. The selected clinical trials demonstrated substantial heterogeneity in baseline patient demographics, sample size, and vitamin D intervention strategies. Serious adverse events attributable to vitamin D supplementation were rare across all studies. On the basis of studies reviewed to date, the strongest evidence supports further research into adjunctive vitamin D therapy for tuberculosis, influenza, and viral upper respiratory tract illnesses. In the selected studies, certain aspects of study design are highlighted to help guide future clinical research in the field.ConclusionMore rigorously designed clinical trials are needed for further evaluation of the relationship between vitamin D status and the immune response to infection as well as for delineation of necessary changes in clinical practice and medical care of patients with vitamin D deficiency in infectious disease settings. (Endocr Pract. 2009;15:438-449)