Enhancing 1α-Hydroxylase Activity with the 25-Hydroxyvitamin D-1α-Hydroxylase Gene in Cultured Human Keratinocytes and Mouse Skin

1α,25-Dihydroxyvitamin D3 (1α,25(OH)2D3) and its analogs are used to treat psoriasis because of their potent antiproliferative activity. They have the potential for causing hypercalcemia, however, and patients often become resistant to the drug. We examined the feasibility of enhancing the cutaneous production of 1α,25(OH)2D3 using a human 25-hydroxyvitamin D-1α-hydroxylase (1α-OHase) plasmid. The 1α-OHase gene was fused to the green fluorescent protein gene (1α-OHase-GFP) driven by the cytomegalovirus promoter. Transfection of cultured normal human keratinocytes with the 1α-OHase-GFP plasmid resulted in a marked increase in the expression of 1α-OHase-GFP in the mitochondria. Transfection of keratinocytes with 1α-OHase-GFP or 1α-OHase plasmids in vitro enhanced the 1α-OHase activity substantially and increased the sensitivity of the keratinocytes to the antiproliferative effect of 25(OH)D3. The 1α-OHase-GFP plasmid was topically applied to shaved C57/BL6 mice. Twenty-four hours after topical application, immunohistochemical analysis of the skin for 1α-OHase-GFP revealed the presence of 1α-OHase-GFP in the epidermis and epidermal appendages including the hair follicles. The results from this study offer a unique new approach for the topical treatment of hyperproliferative disorders such as psoriasis and skin cancer using the 1α-OHase gene that could locally increase the production of 1α,25(OH)2D3 without causing hypercalcemia or resistance

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

Tuberculosis incidence correlates with sunshine : an ecological 28-year time series study

Birmingham is the largest UK city after London, and central Birmingham has an annual tuberculosis incidence of 80 per 100,000. We examined seasonality and sunlight as drivers of tuberculosis incidence. Hours of sunshine are seasonal, sunshine exposure is necessary for the production of vitamin D by the body and vitamin D plays a role in the host response to tuberculosis. Methods: We performed an ecological study that examined tuberculosis incidence in Birmingham from Dec 1981 to Nov 2009, using publicly-available data from statutory tuberculosis notifications, and related this to the seasons and hours of sunshine (UK Meteorological Office data) using unmeasured component models. Results: There were 9,739 tuberculosis cases over the study period. There was strong evidence for seasonality, with notifications being 24.1% higher in summer than winter (p<0.001). Winter dips in sunshine correlated with peaks in tuberculosis incidence six months later (4.7% increase in incidence for each 100 hours decrease in sunshine, p<0.001). Discussion and Conclusion: A potential mechanism for these associations includes decreased vitamin D levels with consequent impaired host defence arising from reduced sunshine exposure in winter. This is the longest time series of any published study and our use of statutory notifications means this data is essentially complete. We cannot, however, exclude the possibility that another factor closely correlated with the seasons, other than sunshine, is responsible. Furthermore, exposure to sunlight depends not only on total hours of sunshine but also on multiple individual factors. Our results should therefore be considered hypothesis-generating. Confirmation of a potential causal relationship between winter vitamin D deficiency and summer peaks in tuberculosis incidence would require a randomized-controlled trial of the effect of vitamin D supplementation on future tuberculosis incidence

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

Effects of Artificial Ultraviolet Light Exposure on Reproductive Success of the Female Panther Chameleon (Furcifer pardalis) in Captivity

Having previously documented experimentally the need for ultraviolet B (UVB) irradiation (290-315 nm) in the light environment of captive female panther chameleons (Furcifer pardalis) to ensure hatching success of their eggs, we investigated optimal UVB irradiation levels. From 1996-1998 28 hatchling female panther chameleons were raised to maturity and bred (using vitamin and mineralfortified insect diets low in vitamin D) in nine different artificial UVB light environments. Seven of the environments included long (12 hr/day) low irradiation exposures ranging from 1.7 to 22 mW/cm 2 UVB, with a corresponding conversion of provitamin D 3 to photoproducts in in vitro models of 0.18 to 1.52% in 2 hr. Two environments included short (0.5 and 1.0 hr/day), high irradiation exposures of 55 and 49 mW/cm 2 UVB, respectively, with a corresponding conversion of provitamin D 3 to photoproducts in in vitro models of 8.3% to 14.6% in the respective 0.5-and 1.0-hr time periods. Females raised with the mid-level long/low exposures (5-15 mW/cm 2 UVB; 0.52-1.32% conversion to photoproducts in in vitro models) produced viable eggs with a significantly higher percentage of hatching compared to those with the extreme (highest or lowest) long/low exposures. Those raised with the short-/high-exposure environments produced viable eggs with a generally high percentage of hatching, but success was variable. The results and techniques for light quality assessment are interpreted, with recommendations for practical application by the *Correspondence to

Vitamin D in the general population of young adults with autism in the Faroe Islands

Vitamin D deficiency has been proposed as a possible risk factor for developing autism spectrum disorder (ASD). 25-Hydroxyvitamin D3 (25(OH)D3) levels were examined in a cross-sectional population-based study in the Faroe Islands. The case group consisting of a total population cohort of 40 individuals with ASD (aged 15–24 years) had significantly lower 25(OH)D3 than their 62 typically-developing siblings and their 77 parents, and also significantly lower than 40 healthy age and gender matched comparisons. There was a trend for males having lower 25(OH)D3 than females. Effects of age, month/season of birth, IQ, various subcategories of ASD and Autism Diagnostic Observation Schedule score were also investigated, however, no association was found. The very low 25(OH)D3 in the ASD group suggests some underlying pathogenic mechanism

Lipid-soluble Vitamins A, D, and E in HIV-Infected Pregnant women in Tanzania.

There is limited published research examining lipid-soluble vitamins in human immunodeficiency virus (HIV)-infected pregnant women, particularly in resource-limited settings. This is an observational analysis of 1078 HIV-infected pregnant women enrolled in a trial of vitamin supplementation in Tanzania. Baseline data on sociodemographic and anthropometric characteristics, clinical signs and symptoms, and laboratory parameters were used to identify correlates of low plasma vitamin A (<0.7 micromol/l), vitamin D (<80 nmol/l) and vitamin E (<9.7 micromol/l) status. Binomial regression was used to estimate risk ratios and 95% confidence intervals. Approximately 35, 39 and 51% of the women had low levels of vitamins A, D and E, respectively. Severe anemia (hemoglobin <85 g/l; P<0.01), plasma vitamin E (P=0.02), selenium (P=0.01) and vitamin D (P=0.02) concentrations were significant correlates of low vitamin A status in multivariate models. Erythrocyte Sedimentation Rate (ESR) was independently related to low vitamin A status in a nonlinear manner (P=0.01). The correlates of low vitamin D status were CD8 cell count (P=0.01), high ESR (ESR >81 mm/h; P<0.01), gestational age at enrollment (nonlinear; P=0.03) and plasma vitamins A (P=0.02) and E (P=0.01). For low vitamin E status, the correlates were money spent on food per household per day (P<0.01), plasma vitamin A concentration (nonlinear; P<0.01) and a gestational age <16 weeks at enrollment (P<0.01). Low concentrations of lipid-soluble vitamins are widely prevalent among HIV-infected women in Tanzania and are correlated with other nutritional insufficiencies. Identifying HIV-infected persons at greater risk of poor nutritional status and infections may help inform design and implementation of appropriate interventions

Inherited Variation in Vitamin D Genes Is Associated With Predisposition to Autoimmune Disease Type 1 Diabetes

Objective: Vitamin D deficiency (25-hydroxyvitamin D [25(OH)D] <50 nmol/L) is commonly reported in both children and adults worldwide, and growing evidence indicates that vitamin D deficiency is associated with many extraskeletal chronic disorders, including the autoimmune diseases type 1 diabetes and multiple sclerosis. Research Design and Methods: We measured 25(OH)D concentrations in 720 case and 2,610 control plasma samples and genotyped single nucleotide polymorphisms from seven vitamin D metabolism genes in 8,517 case, 10,438 control, and 1,933 family samples. We tested genetic variants influencing 25(OH)D metabolism for an association with both circulating 25(OH)D concentrations and disease status. Results: Type 1 diabetic patients have lower circulating levels of 25(OH)D than similarly aged subjects from the British population. Only 4.3 and 18.6% of type 1 diabetic patients reached optimal levels ($\geq$75 nmol/L) of 25(OH)D for bone health in the winter and summer, respectively. We replicated the associations of four vitamin D metabolism genes (GC, DHCR7, CYP2R1, and CYP24A1) with 25(OH)D in control subjects. In addition to the previously reported association between type 1 diabetes and CYP27B1 (P = 1.4 × 10$^{−4}$), we obtained consistent evidence of type 1 diabetes being associated with DHCR7 (P = 1.2 × 10$^{−3}$) and CYP2R1 (P = 3.0 × 10$^{−3}$). Conclusions: Circulating levels of 25(OH)D in children and adolescents with type 1 diabetes vary seasonally and are under the same genetic control as in the general population but are much lower. Three key 25(OH)D metabolism genes show consistent evidence of association with type 1 diabetes risk, indicating a genetic etiological role for vitamin D deficiency in type 1 diabetes

Serum 25-Hydroxyvitamin D and Risk of Lung Cancer in Male Smokers: A Nested Case-Control Study

A role for vitamin D in cancer risk reduction has been hypothesized, but few data exist for lung cancer. We investigated the relationship between vitamin D status, using circulating 25-hydroxyvitamin D [25(OH)D], and lung cancer risk in a nested case-control study within the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study of Finnish male smokers.Lung cancer cases (n = 500) were randomly selected based on month of blood collection, and 500 controls were matched to them based on age and blood collection date. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using multivariate-adjusted conditional logistic regression. To account for seasonal variation in 25(OH)D concentrations, season-specific and season-standardized quintiles of 25(OH)D were examined, and models were also stratified on season of blood collection (darker season = November-April and sunnier season = May-October). Pre-determined, clinically-defined cutpoints for 25(OH)D and 25(OH)D as a continuous measure were also examined.Overall, 25(OH)D was not associated with lung cancer. Risks were 1.08 (95% CI 0.67-1.75) and 0.83 (95% CI 0.53-1.31) in the highest vs. lowest season-specific and season-standardized quintiles of 25(OH)D, respectively, and 0.91 (95% CI 0.48-1.72) for the ≥75 vs. <25 nmol/L clinical categories. Inverse associations were, however, suggested for subjects with blood collections from November-April, with ORs of 0.77 (95% CI 0.41-1.45, p-trend = 0.05) and 0.65 (95% CI 0.37-1.14, p-trend = 0.07) in the highest vs. lowest season-specific and season-standardized quintiles of 25(OH)D, respectively, and 0.61 (95% CI 0.24-1.52, p-trend = 0.01) for ≥75 vs. <25 nmol/L. We also found 11% lower risk for a 10 nmol/L increase in 25(OH)D in the darker season based on the continuous measure (OR = 0.89, 95% CI 0.81-0.98, p = 0.02).In this prospective study of male smokers, circulating 25(OH)D was not associated with lung cancer risk overall, although inverse associations were suggested among those whose blood was drawn during darker months