A population-based cohort study on sun habits and endometrial cancer

Background:No large cohort study has examined the risk of endometrial cancer in relation to sun exposure.Methods:A population-based cohort study of 29 508 women who answered a questionnaire in 1990-92, of whom 24 098 responded to a follow-up enquiry in 2000-02. They were followed for an average of 15.5 years.Results:Among the 17 822 postmenopausal women included, 166 cases of endometrial cancer were diagnosed. We used a multivariate Cox regression analysis adjusting for age and other selected demographic variables to determine the risk of endometrial cancer. Women using sun beds >3 times per year reduced their hazard risk (HR) by 40% (0.6, 95% confidence interval (CI) 0.4-0.9) or by 50% when adjusting for body mass index or physical activity (HR 0.5, 95% CI 0.3-0.9), and those women who were sunbathing during summer reduced their risk by 20% (HR 0.8 95% CI 0.5-1.5) compared with women who did not expose themselves to the sun or to artificial sun (i.e., sun beds).Conclusion:Exposure to artificial sun by the use of sun beds >3 times per year was associated with a 40% reduction in the risk of endometrial cancer, probably by improving the vitamin D levels during winter.British Journal of Cancer advance online publication, 23 June 2009; doi:10.1038/sj.bjc.6605149 www.bjcancer.com

Vitamin D inadequacy in Belgian postmenopausal osteoporotic women

BACKGROUND: Inadequate serum vitamin D [25(OH)D] concentrations are associated with secondary hyperparathyroidism, increased bone turnover and bone loss, which increase fracture risk. The objective of this study is to assess the prevalence of inadequate serum 25(OH)D concentrations in postmenopausal Belgian women. Opinions with regard to the definition of vitamin D deficiency and adequate vitamin D status vary widely and there are no clear international agreements on what constitute adequate concentrations of vitamin D. METHODS: Assessment of 25-hydroxyvitamin D [25(OH)D] and parathyroid hormone was performed in 1195 Belgian postmenopausal women aged over 50 years. Main analysis has been performed in the whole study population and according to the previous use of vitamin D and calcium supplements. Four cut-offs of 25(OH)D inadequacy were fixed : < 80 nmol/L, <75 nmol/L, < 50 nmol/L and < 30 nmol/L. RESULTS: Mean (SD) age of the patients was 76.9 (7.5) years, body mass index was 25.7 (4.5) kg/m(2). Concentrations of 25(OH)D were 52.5 (21.4) nmol/L. In the whole study population, the prevalence of 25(OH)D inadequacy was 91.3 %, 87.5 %, 43.1 % and 15.9% when considering cut-offs of 80, 75, 50 and 30 nmol/L, respectively. Women who used vitamin D supplements, alone or combined with calcium supplements, had higher concentrations of 25(OH)D than non-users. Significant inverse correlations were found between age/serum PTH and serum 25(OH)D (r = -0.23/r = -0.31) and also between age/serum PTH and femoral neck BMD (r = -0.29/r = -0.15). There is a significant positive relation between age and PTH (r = 0.16), serum 25(OH)D and femoral neck BMD (r = 0.07). (P < 0.05) Vitamin D concentrations varied with the season of sampling but did not reach statistical significance (P = 0.09). CONCLUSION: This study points out a high prevalence of vitamin D inadequacy in Belgian postmenopausal osteoporotic women, even among subjects receiving vitamin D supplements

Vitamin D Status in Relation to Glucose Metabolism and Type 2 Diabetes in Septuagenarians

Objective: Vitamin D deficiency is thought to be a risk factor for development of type 2 diabetes, and elderly subjects at northern latitudes may therefore be at particular risk. Research Design and Methods: Vitamin D status was assessed from serum concentrations of 25-hydroxyvitamin D3 [25(OH)D3] in 668 Faroese residents aged 70–74 years (64% of eligible population). We determined type 2 diabetes prevalence from past medical histories, fasting plasma concentrations of glucose, and/or glycosylated hemoglobin (HbA1c). Results: We observed 70 (11%) new type 2 diabetic subjects, whereas 88 (13%) were previously diagnosed. Having vitamin D status <50 nmol/L doubled the risk of newly diagnosed type 2 diabetes after adjustment for BMI, sex, exposure to polychlorinated biphenyls, serum triacylglyceride concentration, serum HDL concentration, smoking status, and month of blood sampling. Furthermore, the HbA1c concentration decreased at higher serum 25(OH)D3 concentrations independent of covariates. Conclusions: In elderly subjects, vitamin D sufficiency may provide protection against type 2 diabetes. Because the study is cross-sectional, intervention studies are needed to elucidate whether vitamin D could be used to prevent development of type 2 diabetes

Regional variation and determinants of vitamin D status in sunshine-abundant Thailand

<p>Abstract</p> <p>Background</p> <p>Vitamin D insufficiency is highly prevalent. Most of the studies concerning vitamin D status were generated from countries situated at temperate latitudes. It is less clear what the extent of vitamin D insufficiency is in countries situated in the tropics and how geographical regions within country would affect vitamin D status. In the present study, we investigated vitamin D status in Thais according to geographical regions and other risk factors.</p> <p>Methods</p> <p>Subjects consisted of 2,641 adults, aged 15 - 98 years, randomly selected from the Thai 4th National Health Examination Survey (2008-9) cohort. Serum 25 hydroxyvitamin D were measured by liquid chromatography/tandem mass spectrometry. Data were expressed as mean ± SE.</p> <p>Results</p> <p>Subjects residing in Bangkok, the capital city of Thailand, had lower 25(OH)D levels than other parts of the country (Bangkok, central, northern, northeastern and southern regions: 64.8 ± 0.7, 79.5 ± 1.1, 81.7 ± 1.2, 82.2 ± 0.8 and 78.3 ± 1.3 nmol/L, respectively; <it>p </it>< 0.001). Within each region, except for the northeastern part of the country, subjects living inside municipal areas had lower circulating 25(OH)D (central, 77.0 ± 20.9 nmol/L vs 85.0 ± 22.1 nmol/L, <it>p </it>< 0.001; north 79.3 ± 22.1 nmol/L vs 86.8 ± 21.8 nmol/L, <it>p </it>< 0.001; northeast 84.1 ± 23.3 nmol/L vs 87.3 ± 20.9 nmol/L, <it>p </it>= 0.001; south, 76.6 ± 20.5 nmol/L vs 85.2 ± 24.7 nmol/L, <it>p </it>< 0.001). Overall, the prevalence of vitamin D insufficiency was 64.6%, 46.7%, and 33.5% in Bangkok, municipal areas except Bangkok, and outside municipal area in other parts of the country, respectively. In addition, the prevalence of vitamin D insufficiency according to geographical regions was 43.1%, 39.1%, 34.2% and 43.8% in the central, north, northeast and south, respectively. After controlling for covariates in multiple linear regression analysis, the results showed that low serum 25(OH)D levels were associated with being female, younger age, living in urban and Bangkok.</p> <p>Conclusions</p> <p>Vitamin D insufficiency is common and varies across geographical regions in Thailand.</p

Vitamin D Levels in Asymptomatic Adults-A Population Survey in Karachi, Pakistan

Background: It is well established that low levels of 25(OH) Vitamin D (/dL) are a common finding world over, affecting over a billion of the global population. Our primary objective was to determine the prevalence of vitamin D deficiency and insufficiency in the asymptomatic adult population of Karachi, Pakistan and the demographic, nutritional and co-morbidity characteristics associated with serum vitamin D levels. Methods: A cross-sectional population survey was conducted at two spaced out densely populated areas of the city. Serum levels of 25OH vitamin D were measured and GFR as renal function was assessed by using 4 variable MDRD formula. Results: Our sample of 300 had a median age of 48(interquartile range 38-55) years. The median level of serum vitamin D was 18.8 (IQ range 12.65-24.62) ng/dL. A total of 253 (84.3%) respondents had low levels (/dL) of 25OH vitamin D. Serum PTH and vitamin D were negatively correlated (r = -0.176, p = 0.001). The median PTH in the vitamin D sufficiency group was 38.4 (IQ range28.0-48.8)pg/mL compared with 44.4 (IQ range 34.3-56.8) pg/mL in the deficiency group (p = 0.011).The median serum calcium level in the sample was 9.46(IQ range 9.18-9.68) ng/dL. Low serum levels of vitamin D were not associated with hypertension (p = 0.771) or with an elevated spot blood pressure (p = 0.164).In our sample 75(26%) respondents had an eGFR corresponding to stage 2 and stage 3 CKD. There was no significant correlation between levels of vitamin D and eGFR (r = -0.127, p-value = 0.277). Respondents using daily vitamin D supplements had higher 25 OH vitamin D levels (p-value = 0.021). Conclusion: We observed a high proportion of the asymptomatic adult population having low levels of vitamin D and subclinical deterioration of eGFR. The specific cause(s) for this observed high prevalence of low 25OH vitamin D levels are not clear and need to be investigated further upon

Determining Vitamin D Status: A Comparison between Commercially Available Assays

Background: Vitamin D is not only important for bone health but can also affect the development of several non-bone diseases. The definition of vitamin D insufficiency by serum levels of 25-hydroxyvitamin D depends on the clinical outcome but might also be a consequence of analytical methods used for the definition. Although numerous 25-hydroxyvitamin D assays are available, their comparability is uncertain. We therefore aim to investigate the precision, accuracy and clinical consequences of differences in performance between three common commercially available assays. Methodology/Principal Findings: Serum 25-hydroxyvitamin D levels from 204 twins from the Swedish Twin Registry were determined with high-pressure liquid chromatography-atmospheric pressure chemical ionization-mass spectrometry (HPLCAPCI-MS), a radioimmunoassay (RIA) and a chemiluminescent immunoassay (CLIA). High inter-assay disagreement was found. Mean 25-hydroxyvitamin D levels were highest for the HPLC-APCI-MS technique (85 nmol/L, 95% CI 81-89), intermediate for RIA (70 nmol/L, 95% CI 66-74) and lowest with CLIA (60 nmol/L, 95% CI 56-64). Using a 50-nmol/L cut-off, 8% of the subjects were insufficient using HPLC-APCI-MS, 22% with RIA and 43% by CLIA. Because of the heritable component of 25-hydroxyvitamin D status, the accuracy of each method could indirectly be assessed by comparison of within-twin pair correlations. The strongest correlation was found for HPLC-APCI-MS (r = 0.7), intermediate for RIA (r = 0.5) and lowest for CLIA (r = 0.4). Regression analyses between the methods revealed a non-uniform variance (p&lt;0.0001) depending on level of 25-hydroxyvitamin D. Conclusions/Significance: There are substantial inter-assay differences in performance. The most valid method was HPLCAPCI-MS. Calibration between 25-hydroxyvitamin D assays is intricate

Effect of vitamin D supplementation on bone health parameters of healthy young Indian women

Summary There is a huge prevalence of hypovitaminosis D in the Indian population. We studied the efficacy and safety of oral vitamin D supplementation in apparently healthy adult women. Monthly cholecalciferol given orally, 60,000 IU/month during summers and 120,000 IU/month during winters, safely increases 25-hydroxyvitamin D (25 (OH)D) levels to near normal levels. Introduction There is a huge burden of hypovitaminosis D in the Indian population. The current recommendation for vitamin D supplementation is not supported by sufficient evidence. Methods Study subjects included 100 healthy adult women of reproductive age group from hospital staff. They wer

High prevalence of vitamin D deficiency among women of child-bearing age in Lahore Pakistan, associating with lack of sun exposure and illiteracy

BACKGROUND: Vitamin D status is a key determinant of maternal and neonatal health. Deficiency has been reported to be common in Pakistani women, but information regarding environmental and genetic determinants of vitamin D status is lacking in this population. METHODS: We conducted a cross-sectional study among three groups of healthy women living in Lahore, Pakistan: university students, students or employees of Medrasas or Islamic Institutes, and employees working in office, hospital or domestic settings. Multivariate analysis was performed to identify environmental and genetic determinants of vitamin D status: polymorphisms in genes encoding the vitamin D receptor, vitamin D 25-hydroxylase enzyme CYP2R1 and vitamin D binding protein [DBP] were investigated. We also conducted analyses to identify determinants of body ache and bone pain in this population, and to determine the sensitivity and specificity of testing for hypocalcaemia and raised serum alkaline phosphatase to screen for vitamin D deficiency. RESULTS: Of 215 participants, 156 (73 %) were vitamin D deficient (serum 25[OH]D <50 nmol/L). Risk of vitamin D deficiency was independently associated with illiteracy (adjusted OR 4.0, 95 % CI 1.03–15.52, P = 0.04), <30 min sun exposure per day (adjusted OR 2.13, 95 % CI 1.08–4.19, P = 0.02), sampling in January to March (adjusted OR 2.38, 95 % CI 1.20–4.70), P = 0.01) and lack of regular intake of multivitamins (adjusted OR 2.61, 95 % CI 1.32–5.16, p = 0.005). Participants with the GG genotype of the rs4588 polymorphism in the gene encoding vitamin D binding protein tended to have lower 25(OH)D concentrations than those with GT/TT genotypes (95 % CI for difference 22.7 to −0.13 nmol/L, P = 0.053). Vitamin D deficiency was independently associated with increased risk of body ache or bone pain (adjusted OR 4.43, 95 % CI 2.07 to 9.49, P = 0.001). Hypocalcaemia (serum calcium concentration ≤9.5 mg/dL) and raised alkaline phosphatase concentration (≥280 IU/L) had low sensitivity and very low specificity for identification of vitamin D deficiency. CONCLUSION: Vitamin D deficiency is common among healthy women of child-bearing age in Lahore, Pakistan: illiteracy, decreased sun exposure and lack of multivitamin intake are risk factors

Locally harvested foods support serum 25-hydroxyvitamin D sufficiency in an indigenous population of Western Alaska

Background: Low serum vitamin D is associated with higher latitude, age, body fat percentage and low intake of fatty fish. Little documentation of vitamin D concentrations is available for Alaska Native populations. Objective: This study was undertaken to investigate serum 25-hydroxyvitamin D (25(OH)D) concentrations of the Yup'ik people of southwestern Alaska in relation to demographic and lifestyle variables, particularly with the use of locally harvested (local) foods. Design: Cross-sectional study. Methods: We estimated 25(OH)D, dietary vitamin D and calcium, percent of energy from local foods and demographic variables in 497 Yup'ik people (43% males) aged 14–92 residing in southwestern Alaska. Sampling was approximately equally divided between synthesizing and non-synthesizing seasons, although the preponderance of samples were drawn during months of increasing daylight. Results: Mean vitamin D intake was 15.1±20.2 µg/d, while local foods accounted for 22.9±17.1% of energy intake. The leading sources of vitamin D were local fish (90.1%) followed by market foods. Mean 25(OH)D concentration was 95.6±40.7 nmol/L. Participants in the upper 50th percentile of 25(OH)D concentration tended to be older, male, of lower body mass index, sampled during the synthesizing season, and among the upper 50th percentile of local food use. Conclusions: A shift away from locally harvested foods will likely increase the risk for serum 25(OH)D insufficiency in this population