Fractional Sunburn Threshold UVR Doses Generate Equivalent Vitamin D and DNA Damage in Skin Types I-VI but with Epidermal DNA Damage Gradient Correlated to Skin Darkness.

Public health guidance recommends limiting sun exposure to sub-sunburn levels, but it is unknown whether these can gain vitamin D (for musculoskeletal health) while avoiding epidermal DNA damage (initiates skin cancer). Well-characterized healthy humans of all skin types (I-VI, lightest to darkest skin) were exposed to a low-dose series of solar simulated UVR of 20%-80% their individual sunburn threshold dose (minimal erythema dose). Significant UVR dose responses were seen for serum 25-hydroxyvitamin D and whole epidermal cyclobutane pyrimidine dimers (CPDs), with as little as 0.

Daily supplementation with 15 μg vitamin D compared with vitamin D to increase wintertime 25-hydroxyvitamin D status in healthy South Asian and white European women: a 12-wk randomized, placebo-controlled food-fortification trial.

There are conflicting views in the literature as to whether vitamin D and vitamin D are equally effective in increasing and maintaining serum concentrations of 25-hydroxyvitamin D [25(OH)D], particularly at lower doses of vitamin D. We aimed to investigate whether vitamin D or vitamin D fortified in juice or food, at a relatively low dose of 15 μg/d, was effective in increasing serum total 25(OH)D and to compare their respective efficacy in South Asian and white European women over the winter months within the setting of a large randomized controlled trial. A randomized, double-blind, placebo-controlled food-fortification trial was conducted in healthy South Asian and white European women aged 20-64 y ( = 335; Surrey, United Kingdom) who consumed placebo, juice supplemented with 15 μg vitamin D, biscuit supplemented with 15 μg vitamin D, juice supplemented with 15 μg vitamin D, or biscuit supplemented with 15 μg vitamin D daily for 12 wk.

Vitamin D status of White pregnant women and infants at birth and 4 months in North West England: A cohort study.

The prevalence of vitamin D deficiency in pregnant white-skinned women (WSW) and their infants has not been investigated at northern latitudes in a developed county. A 2-year observational cohort study was undertaken in the North West of England to determine 25-hydroxyvitamin D (25OHD) levels in WSW and their infants during pregnancy and 4 months postdelivery and to explore factors associated with these levels. Nutritional and lifestyle questionnaires were completed and 25OHD levels measured at 28 weeks and 4 months postdelivery.

Sun Exposure Behavior, Seasonal Vitamin D Deficiency, and Relationship to Bone Health in Adolescents.

Context: Vitamin D is essential for bone health in adolescence, when there is rapid bone mineral content accrual. Because cutaneous sun exposure provides vitamin D, there is no recommended oral intake for UK adolescents.

Objective: Our objective was to assess seasonal vitamin D status and its contributors in white Caucasian adolescents and examine bone health in those found deficient.

Relationship between vitamin D status and leukocytes in hospitalised cats.

Objectives Vitamin D deficiency, as assessed by serum 25-hydroxyvitamin D (25[OH]D) concentrations, has been linked to markers of systemic inflammation in human and canine medicine. However, the relationship between vitamin D status and inflammation has not been previously investigated in cats. The aim of this study was to examine the relationship between serum 25(OH)D concentrations and leukocyte counts in hospitalised sick cats.

Vitamin D status predicts reproductive fitness in a wild sheep population.

Vitamin D deficiency has been associated with the development of many human diseases, and with poor reproductive performance in laboratory rodents. We currently have no idea how natural selection directly acts on variation in vitamin D metabolism due to a total lack of studies in wild animals. Here, we measured serum 25 hydroxyvitamin D (25(OH)D) concentrations in female Soay sheep that were part of a long-term field study on St Kilda.

A modeling approach to determine how much UV radiation is available across the UK and Ireland for health risk and benefit studies.

A detailed map of the available UV across the UK from 2003 to 2012 is provided. A suite of data derived from climatologies and satellite observations are used to calculate spectral UV irradiance and related weighted doses (erythema, DNA damage, vitamin D). The result is a well-validated tool that has two advantages: (i) the output is simulated spectral UV irradiance that can be weighted with any action spectrum for use in any research studies that require ambient UV data, (ii) reliance on instruments with planned operational lives of at least several years that ensures data and method homogeneity for extension to future studies.

The direction of shift-work rotation impacts metabolic risk independent of chronotype and social jetlag--an exploratory pilot study.

The aim of this pilot study was to explore the risk of metabolic abnormalities in steel workers employed in different shift-work rotations. Male workers in a steel factory [16 employed in a fast clockwise rotation (CW), 18 in slow counterclockwise rotation (CC), 9 day workers (DW); mean age 43.3 ± SD 6.

Differential effects of different vitamin D replacement strategies in patients with diabetes.

Background: The optimal treatment regimen for correcting vitamin D insufficiency in diabetic patients has not been established.

Methods: Two hundred and forty four adult diabetic patients with vitamin D insufficiency were enrolled to receive: Ergocalciferol (D2) 50,000 IU daily over 10 days (500,000 IU) followed by Calcichew D3 (calcium carbonate/Cholecalciferol) BID (~24,000 IU cholecalciferol/month) (ECC) (n=53); Cholecalciferol (D3) 40,000 IU daily over 10 days (400,000 IU) followed by Calcichew D3 BID (~24,000 IU cholecalciferol/month) (CCC) (n=94) or Cholecalciferol 40,000 IU daily over 10 days (400,000 IU) followed by Cholecalciferol 40,000 IU monthly (CC) (n=97). The 25(OH)D, HbA1c, lipids, blood pressure and eGFR were assessed at baseline and after a mean follow up of 8.

Efficacy of a dose range of simulated sunlight exposures in raising vitamin D status in South Asian adults: implications for targeted guidance on sun exposure.

Background: Vitamin D is essential for bone health, and cutaneous synthesis is an important source. South Asians cannot attain adequate amounts of vitamin D by following general recommendations on summer sunlight exposure at northerly latitudes, and increased exposure may be appropriate for improving their vitamin D status.

Objective: We examined the efficacy of a dose range of simulated summer sunlight exposures in raising vitamin D status in UK adults of South Asian ethnicity.

Adaptations in tibial cortical thickness and total volumetric bone density in postmenopausal South Asian women with small bone size.

There is some evidence that South Asian women may have an increased risk of osteoporosis compared with Caucasian women, although whether South Asians are at increased risk of fracture is not clear. It is unknown whether older South Asian women differ from Caucasian women in bone geometry. This is the first study, to the authors' knowledge, to use peripheral Quantitative Computed Tomography (pQCT) to measure radial and tibial bone geometry in postmenopausal South Asian women.

25-Hydroxyvitamin D deficiency is associated with increased aortic stiffness in patients with systemic lupus erythematosus.

Objective: To determine the relationship between serum vitamin D and markers of subclinical cardiovascular disease (CVD) in patients with SLE.

Methods: We recruited SLE patients (≥ 4 ACR 1997 criteria) from outpatient clinics between January 2007 and January 2009. Vitamin D deficiency was defined as serum 25(OH)D <20 ng/ml measured by ELISA.

Recommended summer sunlight exposure amounts fail to produce sufficient vitamin D status in UK adults of South Asian origin.

Background: The cutaneous synthesis of vitamin D is dependent on UVB from sunlight, but melanin reduces the penetration of UVB and thus contributes to vitamin D insufficiency in individuals with darker skin. The national guidance provided on amounts of sunlight exposure in the United Kingdom is for the light-skinned population, and in the absence of dedicated information, darker-skinned people may attempt to follow this guidance.

Objectives: We determined the relative effect of a simulation of UK recommendations of summer sunlight exposure on the vitamin D status of individuals of South Asian ethnicity compared with that of whites.

The vitamin D debate: translating controlled experiments into reality for human sun exposure times.

Exposure to sunlight, specifically the ultraviolet radiation, has both positive and negative health effects. Maximizing the benefits (vitamin D synthesis) while minimizing the damage is a multifaceted problem in which many of the elements are poorly quantified. Here we show how rigorously conducted large sample size laboratory studies of the effect of ultraviolet radiation dose on vitamin D status can be applied to real-life situations.

Recommended summer sunlight exposure levels can produce sufficient (> or =20 ng ml(-1)) but not the proposed optimal (> or =32 ng ml(-1)) 25(OH)D levels at UK latitudes.

Recommendations on limitation of summer sunlight exposure to prevent skin cancer may conflict with requirements to protect bone health through adequate vitamin D levels, the principal source being UVB in summer sunlight. We determined whether sufficient (> or =20 ng ml(-1)) and proposed optimal (> or =32 ng ml(-1)) 25(OH)D levels are attained by following UK guidance advising casual short exposures to UVB in summer sunlight, and performed the study under known conditions to enhance the specificity of future recommendations. During wintertime, when ambient UVB is negligible, 120 white Caucasians, aged 20-60 years, from Greater Manchester, UK (53.

A prospective study of micronutrient status in adolescent pregnancy.

Background: Adolescents are more likely than adults to consume energy-dense, micronutrient-poor diets and to experience adverse pregnancy outcomes.

Objectives: The objectives were to assess micronutrient intake and blood biomarkers prospectively in pregnant adolescents recruited to the About Teenage Eating (ATE) Study and to determine associations with pregnancy outcome.

Design: Pregnant adolescents (n = 500) were recruited from 2 UK inner city populations.

Vitamin D status and muscle function in post-menarchal adolescent girls.

Context: There has been a resurgence of vitamin D deficiency among infants, toddlers, and adolescents in the United Kingdom. Myopathy is an important clinical symptom of vitamin D deficiency, yet it has not been widely studied.

Objective: Our objective was to investigate the relationship of baseline serum 25 hydroxyvitamin D [25(OH)D] concentration and PTH with muscle power and force.

The effect of ultraviolet B-induced vitamin D levels on host resistance to Mycobacterium tuberculosis: a pilot study in immigrant Asian adults living in the United Kingdom.

Asian immigrants to the United Kingdom demonstrate much higher tuberculosis rates than the indigenous population. This is postulated to be because of their low vitamin D levels, consequent upon a combination of diet and their reduced ultraviolet (UV) exposure in the United Kingdom, because vitamin D enhances antimycobacterial activity in in vitro systems. The aim of this study was to examine the relationship between UVB exposure, vitamin D levels and tuberculo-immunity in Asian immigrants in the United Kingdom.

The effect of a low-protein diet in pregnancy on offspring renal calcium handling.

Low birth weight humans and rats exposed to a low-protein diet in utero have reduced bone mineral content. Renal calcium loss during the period of rapid skeletal growth is associated with bone loss. Because young rats exposed to low protein display altered renal function, we tested the hypothesis that renal calcium excretion is perturbed in this model.

A single dose of vitamin D enhances immunity to mycobacteria.

Rationale: Vitamin D was used to treat tuberculosis (TB) in the preantibiotic era. Prospective studies to evaluate the effect of vitamin D supplementation on antimycobacterial immunity have not previously been performed.

Objectives: To determine the effect of vitamin D supplementation on antimycobacterial immunity and vitamin D status.

The effects of Vitamin D metabolites on expression of genes for calcium transporters in human duodenum.

The role of Vitamin D in the regulation of calcium absorption in the intestine is well recognized but the mechanisms of the effects on human genes are surprisingly poorly understood. We have determined the expression of transcripts of the apical membrane calcium transporter TRPV6, the cytoplasmic calcium binding protein calbindin-D9k, the basolateral plasma membrane Ca(2+)-ATPase (PMCA1) and the Vitamin D receptor (VDR) in normal endoscopic duodenal mucosal biopsies using quantitative real-time RT-PCR and related baseline expression to Vitamin D metabolites. TRPV6 transcript levels have been shown to be significantly correlated with serum 1,25(OH)(2)D levels in men, but not overall in women, where negative effects of age predominate.

Observations from the UK Supra-Regional Assay Service laboratory for the measurement of Vitamin D metabolites.

As a Supra-Regional Assay Service (SAS) laboratory, we receive samples from all over the UK. Of these some are sent frozen and others by post or courier. We have examined transport and storage conditions to see whether they affect the measurement of Vitamin D metabolites and potentially contribute to the variation in measurement of 25-hydroxyvitamin D (25OHD) seen in the DEQAS scheme.

Calcium channel TRPV6 expression in human duodenum: different relationships to the vitamin D system and aging in men and women.

Unlabelled: Intestinal absorption of calcium affects bone mineralization and varies greatly. In human duodenum, expression of the calcium channel TRPV6 was directly related to blood 1,25-dihydroxyvitamin D in men, but effects of age with lower median vitamin D receptor levels were more significant in women.

Introduction: The TRPV6 calcium channel/transporter is implicated in animal studies of intestinal calcium absorption, but in humans, its role and relationship to differences in mineral metabolism is unclear.

Vitamin D status and bone mass in UK South Asian women.

Introduction: Low vitamin D status is prevalent among South Asians living in the UK. The relationship, however, between serum 25-hydroxyvitamin D level (25OHD), serum parathyroid level (PTH) and bone mass in this group of women is unknown. The aim of this study was to determine the association between serum PTH, 25OHD and bone mass in a population based sample of young UK South Asian women.

Meat consumption reduces the risk of nutritional rickets and osteomalacia.

Endogenous vitamin D deficiency (low serum 25(OH)D3) is a necessary but insufficient requirement for the genesis of vitamin D-deficiency rickets and osteomalacia. The magnitude of the independent contributions of dietary factors to rachitic and osteomalacic risk remains uncertain. We reanalysed two weighed dietary surveys of sixty-two cases of rickets and osteomalacia and 113 normal women and children.