Limited Sun Exposure Research Articles

Severe Hypocalcemia and Vitamin D Deficiency in Adolescence - A Case Series

Background: Hypocalcemia due to vitamin D (vit D) deficiency is uncommon among adolescents in the US. Only 3% to 6% of those ages 12- to 19-years-old have a vit D level <12 ng/ml.1 We present three cases of severe hypocalcemia secondary to vit D deficiency in non-obese adolescents with restricted diets and limited sun exposure. Clinical Cases: A 14-year-old Ethiopian male with history of absence seizures presented with bloody stool. Incidentally, labs revealed: Ca 5.6 (8.4–10.2) mg/dL, iCal 0.71 (1.2–1.38) mmol/L, PTH 295.1 (10.0–65.0) pg/mL, 25(OH)D <4 (20–100) ng/mL, Mg 1.9 (1.7–2.2) mg/dL, PO4 3.8 (2.5–4.5) mg/dL. He endorsed weight loss and knee pain, but denied paresthesias, tetany and seizures. He was a vegetarian and had minimal sun exposure. EKG and femur X-ray were unremarkable. He was started on IV calcium gluconate initially. Oral calcium carbonate and cholecalciferol were started on days three and four. He was discharged on day ten with iCal 0.84 on oral calcium carbonate and calcitriol.A 16-year-old male with history of autism, ADHD and bipolar disorder presented with a seizure. Labs revealed: Ca 5.7, iCal 0.62, PTH 372, 25(OH)D <4, Mg 1.9, PO4 3.5. Exam showed tetany, carpopedal spasms and positive Trousseau and Chvostek signs. EKG revealed prolonged QTc of 480 (<450) ms. He had a restricted diet and minimal sun exposure. His mother described his gait as “waddling” for the past two years. X-ray revealed bilateral femoral head fractures and evidence of rickets. He underwent bilateral surgical repair. He was started on IV calcium gluconate initially. Oral calcium carbonate and cholecalciferol were started on days two and four. He was discharged on day 14 with iCal 1.01 on oral calcium carbonate and cholecalciferol.A 16-year-old male with history of severe food allergies and restricted diet presented with a seizure. He visited urgent care three months prior for perioral tingling, muscle cramps and chest pain. He started a multivitamin for “low Ca” and “prolonged QTc.” The ED labs revealed: Ca 4.8, PTH 414.8, 25(OH)D 11, Mg 1.9, PO4 5.0, Alk Phos 539 (44–147) IU/L. Exam showed upper extremity twitching and QTc was 543 ms. He received 2 g calcium gluconate IV, then began oral calcium carbonate and cholecalciferol and continued supplementation following discharge on day six. Conclusions: Vit D deficiency among adolescents is re-emerging, likely due to decreasing sun exposure, unbalanced diets and increasing obesity.2 Adolescents with restricted diets due to allergy or behavioral disorders may be at higher risk of vit D deficiency. Increased screening of high-risk adolescents may lead to early identification of cases.

VITAMINA D Y DIABETES MELLITUS. PARTE 1

Introduction: diabetes mellitus (DM) has become a major global public health problem. Vitamin D (VD) deficiency, on the other hand, has pandemic characteristics and its consequences go beyond its known effect on bone metabolism. The discovery of vitamin receptors in various tissues has led to increased interest in non-skeletal functions, many of which are related to the prevention and progression of DM. 25(OH) D is the main circulating form and is the most appropriate and most widely used marker for assessing the nutritional status of VD, since it reflects both endogenous production and intake of the vitamin. Objectives: as a Working Group we proposed to make a review of the topic VD and Diabetes. In this first part we analyzed the VD: metabolic aspects, food intake and controversies about the definition of adequate serum levels. Materials and methods: a bibliographic search was carried out using the PubMed, MEDLINE, Cochrane, Research Gate search engines. The search criteria were "vitamin D", "vitamin D and diabetes", "vitamin D functions, metabolism, sources" "vitamin D toxicity". Complete articles related to the topic were selected. The vitamin D content of foods was obtained from the Souci Fachmann Kraut and USDA food composition data bases. Conclusions: considering the scarce distribution of VD in natural foods, the low consumption of source foods in the Argentine population and the current recommendations to limit sun exposure due to skin cancer, it is necessary to have fortified foods for massive consumption, in addition to milk. Nutritional supplements offer a safe option to supplement the diet as long as serum levels are monitored. There is no consensus on reference levels for considering an individual deficient, although most authors agree on the need to maintain serum levels above 30 ng/ml.

The Determinant of Vitamin D Adequacy in Fishermen

Background: The prevalence of vitamin D deficiency in both developed and developing countries are 30% - 75% with increased risk reported among women, elderly, obese individuals and those with low sun exposure. Fisherman has been acknowledged as an occupation with high sun exposure. However, a previous study showed that 4 in 5 fishermen were vitamin D deficient. The objective of this study is to investigate vitamin D intake and sun exposure among fishermen.&#x0D; Method: This cross-sectional study recruited fishermen residing in the working area of several public health centres in Mataram and West Lombok districts. The subjects were classified as fishermen and non-fishermen. Vitamin D intake and sun exposure were the the main variables.&#x0D; Results: One in two fishermen and three in four non-fishermen exhibited low intake of vitamin D. Fish intake in the fisherman and the non-fisherman groups were 937 gram per week and 652 gram per week, respectively. The most consumed fish was tuna. Fish intake of 937 gram per week was equivalent to ~12 µg vitamin D intake and 23.6 nmol/L vitamin D concentration. The majority of subjects were unable to achieve the optimal UVB radiation. &#x0D; Conclusion: Insufficient vitamin D intake and limited sun exposure are prevalent in fisherman and non-fisherman groups.

Biological, Ecological, and Distributional Aspects of Two Native Species of Lucilia Genus (Diptera: Calliphoridae) of Forensic Interest in Yungas Environments of Argentina.

This study determined the spatial and temporal dynamics of two native neotropical species flies of forensic interest, belonging to the Lucilia (Robineau-Desvoidy) genus. The study focused on their abundance and reproductive behaviors associated with different habitats and phenological parameters. In the Province of Salta, Argentina, monthly samplings were performed over 1 yr in urban, rural, and native habitats, at morning, mid-day, and afternoon periods, controlling the oviposition of captured specimens. Environmental variables were also assessed: cloudiness, precipitation, relative humidity, temperature, and tree cover. Lucilia purpurascens (Walker) appeared to be associated with native habitats, whereas Lucilia ochricornis (Wiedemann) was mainly associated with rural habitats, exhibiting distinct habitat preferences. Two ecotones were also identified: rural-urban and rural-native, suggesting rural habitats promoted habitable conditions at its margins. Both species were recorded at the end of winter to the middle of autumn, with an initial peak in early spring, and a second peak at late summer. These peaks were associated with the highest numbers of laid eggs. Lucilia purpurascens preferred high tree coverings, whereas L. ochricornis resisted areas with intermediate sun, suggesting limited sun exposure was important. The latter was also associated with daily flight activities; during the warm season, the densest catches occurred at morning and afternoon periods, whereas during the cold season, they occurred at mid-day. Climatic variables explained 77% of variability in terms of abundance and oviposition. Synergistic effects were observed between these variables, suggesting that these variables conditioned insect distribution and reproduction, and not just temperature per se.

Poor dietary consumption and limited sun exposure are risk factors for vitamin D deficiency in premenopausal Kuwaiti women: A cross-sectional study

Background: Low serum vitamin D levels are reported constantly among females living in the Arabian Gulf countries, presumably due to their lifestyle, which limits direct sun exposure. Because Vitamin D deficiency has been implicated in a wide range of ailments, healthy females with the deficiency might be at risk for developing many health problems. Thus, the aim was to assess lifestyle risk factors for vitamin D deficiency in healthy women in Kuwait. Methods: A total of 104, disease-free, premenopausal women were recruited for assessment of their serum 25OHD and intact PTH levels. Physical examination, blood withdrawal and interviewer-administered questionnaires were used to collect the relevant data. Associations were detected statistically using nonparametric tests and logistic regression was used to identify risk factors for vitamin D deficiency. Results: Vitamin D deficiency ( < 25 nmol/L) occurred in 84.6%, and hyperparathyroidism ( ≥ 6.9 pmol/L) occurred in 25% of women, among which all were vitamin D deficient. Significant risk factors of vitamin D deficiency were nondaily milk intake (OR:25, CI%:4.2–147), no fish intake (OR:5, CI%:1–22.8), and no weekend sun exposure (OR:8.2, CI%:1.28–52.6). Having PTH ≥ 6 pmol/L was also associated with a higher likelihood of having vitamin D deficiency. Conclusion: Vitamin D deficiency is very common in disease-free, premenopausal Kuwaiti women and can be avoided by improving food consumption and obtaining more sun exposure.

Vitamin D deficiency: It's contributing factors and prevention

Vitamin D deficiency is prevalent across the globe. The most important role of vitamin D is in strengthening the bones. Besides this, vitamin D is likely to be associated with prevention against different types of cancers and chronic diseases like cardiovascular diseases, hypertension, diabetes mellitus and stroke as well as osteoporosis. It also has role in preventing many neurological diseases like depression, chronic fatigue syndrome and neuro-degenerative diseases including Alzheimer’s disease autoimmune diseases, birth defects and periodontal diseases.&#x0D; Main source of vitamin D is sunlight, also called sunshine vitamin. People with old age, dark skinned and obese cannot produce sufficient amount of Vitamin D. Food sources include fatty fish, animal liver, egg yolk and dairy products, though these are poor sources. Vitamin D deficiency is endemic in Pakistan, India, Sri Lanka as well as Middle Eastern Countries. Though it’s sunny there all the year round, still the bulk of population is vitamin D deficient due to limited sun exposure in extremes of high temperature and socio religious reasons. Similarly, population in Europe and America are also affected. Pregnant mothers and infants are more at risk. Population at risk should be screened and treated. Appropriate health policies, public awareness, and fortification of dairy products can definitely prevent as well as address this huge burden of disease.

Effect of Maternal Vitamin D Status on Vitamin D Levels in Early Infancy, in a Tertiary Care Centre in Sri Lanka

Background: Vitamin D deficiency is reported to be prevalent across all age groups in epidemic proportions worldwide including neighbouring countries of Sri Lanka. In Sri Lanka, data on vitamin D status in infants and mothers is lacking and there is no routine supplementation programme, especially in the state sector. Vitamin D deficiency in a population could be multi factorial including limited sun exposure and changing life styles. The purpose of this study was to investigate maternal vitamin D status and its effect on infant level, in a state sector tertiary centre in Sri Lanka. Methods: We did this prospective cohort study in 115 healthy pregnant mothers. Blood was collected for 25(OH)D, parathyroid hormone (PTH) and bone biochemical parameters. Results: Subclinical vitamin D deficiency ( 65.5 pg/mL) in 4%, 19%, 9% in pregnant mothers, lactating mothers and infants respectively. Majority of deficient and insufficient (<20 ng/mL) mothers and infants didn't have secondary hyperparathyroidism. Conclusions: This study concluded that subclinical vitamin D deficiency/insufficiency is found in mothers and their offspring from a tertiary care centre in Sri Lanka. Low maternal 25(OH)D during pregnancy was a risk factor for deficiency in the infant. We suggest further studies on vitamin D levels in a nationally representative sample of mothers and infants to confirm our findings to take a step forward to formulate guidelines for supplementation. In addition, longitudinal studies to evaluate effects of deficiency in infants in Sri Lanka are worthwhile. Further, absence of an expected rise of PTH in deficiency/insufficiency warrants further evaluation of biological significance of PTH in vitamin D deficiency. Funding Statement: Financial assistance by university research grant (Grant No: ASP/01/RE/MED/2015/40). Declaration of Interests: The authors declare that they have no competing interests. Ethics Approval Statement: Ethical clearance for the study was obtained from the Ethics Review Committee, Faculty of Medical Sciences, University of Sri Jayewardenepura, Sri Lanka (Reference No: 22/16). Written informed consent was obtained from all individual participants. All procedures performed in this study involving human participants were in accordance with the ethical standards of the institutional research committee.

Relationship of parent-child sun protection among those at risk for and surviving with melanoma: Implications for family-based cancer prevention.

Preventing melanoma, the most serious form of skin cancer, is an important cancer control priority. This is especially true among children living in families previously affected by the disease because the risks for melanoma typically begin early in life. These risks accrue into adulthood but may be mitigated by parental intervention. Melanoma prevention behaviors that could be associated between adults and their children include use of sunscreen, protective clothing, seeking shade, or limiting sun exposure. This study sought to investigate how parent perceptions and behaviors influence sun protection and avoidance behaviors in their children, among relatives of melanoma survivors. In this cross-sectional study, parents (N = 313), all relatives of people diagnosed with melanoma, were surveyed about their melanoma risk-reduction behaviors and efforts to protect their children from sun exposure. Linear multiple regressions examined associations among parental behaviors, beliefs, and their reports of risk reduction for their children. Parents who practiced high sun protection themselves (i.e., wearing protective clothing, avoiding the sun, using sunscreen) were significantly more likely to report their child also wore protective clothing (B = 0.04, p < .004). Findings suggest that parents' use of risk-reducing behavioral measures extended to protective measures among their children. These findings have implications for the clinical care of melanoma survivors' families, including the design of targeted interventions that alter parental beliefs and behaviors surrounding both their own and their children's cancer prevention strategies.

Serum vitamin D levels in Berliners of Turkish descent \u2013a cross-sectional study

BackgroundVitamin D levels may differ between migrant and non-migrant populations, especially among non-western immigrants living in a country with limited sun exposure such as Germany. This study examined serum vitamin D concentration and associated factors among Berliners with and without Turkish background.MethodsTwo samples (with and without Turkish roots) were recruited in the inner city of Berlin for a cross-sectional study assessing serum vitamin D concentration. Linear regression analyses were used to examine sociodemographic, lifestyle and medical factors associated with serum vitamin D levels.ResultsIn the analyses, we included 537 subjects (39% men and 61% women, age 43.2 ± 12.5 (mean ± standard deviation) years) with and 112 without Turkish background (46% men and 54% women, age 46.7 ± 14.6 years). The Turkish sample had lower mean (95%-Confidence Interval) vitamin D levels than the non-Turkish sample: 22.7 nmol/L (21.5;23.9) vs 34.7 nmol/L (31.9;37.5), p < 0.001. In the Turkish female subgroup, veiled women had considerably lower levels than unveiled women: 14.4 nmol/L (11.5;17.3) vs 24.9 nmol/L (23.1;26.7), p < 0.001. Multivariable regression analysis revealed that among the Berliners of Turkish descent, being active less than 150 min per day, and being overweight/obese were independently associated with a lower vitamin D concentration. In the non-migrant sample besides being overweight and obese, female sex was associated with lower vitamin D concentrations.ConclusionsSerum vitamin D levels were considerably low in Berliners of Turkish descent, and especially in veiled women. Potentially modifiable factors of low vitamin D levels were high BMI and low physical activity. These findings should be considered in the development of future public health strategies for subpopulations with Turkish migration background.

Vitamin D concentrations among older adults according to physical disability status: NHANES 2007-2014.

Background: older adults are at increased risk of vitamin D deficiency as a result of limited sun exposure and inadequate vitamin D intake. Despite this evidence, there are scarce data regarding the concentration of 25(OH)D and its metabolites among older adults with physical disability. Methods: the National Health and Nutrition Examination Survey 2007-2014 data were collected to compare 25(OH)D3, 25(H)D2, and total 25(OH)D concentrations among adults aged 60 years and older with and without physical disability. Moreover, general linear models adjusted for potential confounders were used to examine the independent effect of vitamin D intake, physical activity status and body mass index (BMI) categories on 25(OH)D concentrations by disability status. Results: of 6,250 older adults, 17.9% were defined as physically disabled. 25(OH)D concentrations were 71.3 and 78.2 nmol/l in subjects with and without disability, respectively. However, after adjustment for potential confounders, similar 25(OH)D concentrations were seen between disabled subjects and their non-disabled counterparts (75.6 vs 77.5 nmol/l; p = 1.17). In contrast, older adults with disability had significantly increased 25(OH)D2 concentrations (8.3 vs 6.1 nmol/l; p < 0.05). Notably, older adults with a daily vitamin D intake of ≥ 15 mcg achieved sufficient 25(OH)D concentrations, regardless of their disability status. Conclusion: 25(OH)D concentrations did not significantly differ among older adults by disability status. This finding was attributed to increased 25(OH)D2 concentrations among those with physical disability. Thus, adequate vitamin D intake is an effective strategy to maintain sufficient 25(OH)D concentrations, particularly among disabled older adults.

Sun exposure among teenage and young adult cancer survivors in the United Kingdom

Skin cancers are a common form of second malignant neoplasm among teenage and young adult cancer survivors (TYACS). The Children's Oncology Group specifies that TYACS should adhere to safe sun practices and be screened for skin cancer annually. Cross-sectional self-report data collected by our group indicate over a third of TYACS (n=229; mean age: 19.8 years) intentionally sunbathe, with many reporting sunburn. TYACS sunbathing, sunburn, and sunbed use are similar to the general population (P>0.05). These data suggest TYACS require intervention to limit sun exposure and improve their sun safety habits.

Association of vitamin D and cardiovascular health

Vitamin D insufficiency or deficiency is highly prevalent due to limited sun exposure especially in urban and elderly population. Vitamin D is now increasingly recognized as a hormone responsible for numerous physiologic functions in different cells and tissues of the human body including heart. Vitamin D has been shown to be linked with hypertension, acute coronary syndrome, heart failure, and atrial fibrillation. This review briefly overviews the relationship between vitamin D deficiency, its supplementation and outcome in cardiovascular health.Nepalese Heart Journal 2018; 15(1): 17-21.

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 0.2 minimal erythema dose concurrently producing 25-hydroxyvitamin D and CPD. Fractional MEDs generated equivalent levels of whole epidermal CPD and 25-hydroxyvitamin D across all skin types. Crucially, we showed an epidermal gradient of CPD formation strongly correlated with skin darkness (r = 0.74, P < 0.0001), which reflected melanin content and showed increasing protection across the skin types, ranging from darkest skin, where high CPD levels occurred superficially, with none in the germinative basal layer, to lightest skin, where CPD levels were induced evenly across the epidermal depth. People with darker skin can be encouraged to use sub-sunburn UVR-exposure to enhance their vitamin D. In people with lighter skin, basal cell damage occurs concurrent with vitamin D synthesis at exquisitely low UVR levels, providing an explanation for their high skin cancer incidence; greater caution is required.

Lifestyle Modifications and Policy Implications for Primary and Secondary Cancer Prevention: Diet, Exercise, Sun Safety, and Alcohol Reduction.

Improved cancer treatments and cancer detection methods are not likely to completely eradicate the burden of cancer. Primary prevention of cancer is a logical strategy to use to control cancer while also seeking novel treatments and earlier detection. Lifestyle modification strategies to improve primary prevention and risk reduction for the development of cancer include choosing a healthy diet with an emphasis on plant sources, maintaining a healthy weight throughout life, being physically active, regularly using sunscreen and wearing protective clothing, limiting sun exposure during the hours of 10 AM to 2 PM, avoiding indoor tanning, and reducing or eliminating alcohol use. In addition to continued use of ongoing education of the public, health care providers, and cancer support communities, other policy and public health efforts should be pursued as well. Examples of supported and successful policy approaches are included in this article, including efforts to limit indoor tanning and improve community-wide interventions to reduce ultraviolet radiation exposure as well as to formally support various alcohol policy strategies including increasing alcohol taxes, reducing alcohol outlet density, improving clinical screening for alcohol use disorders, and limiting youth exposure to alcohol marketing and advertising. These prevention strategies are expected to have the largest impact on the development of melanoma as well as breast, colorectal, head and neck, liver, and esophageal cancers. The impact of these strategies as secondary prevention is less well understood. Areas of additional needed research and implementation are also highlighted. Future areas of needed research are the effects of these modifications after the diagnosis of cancer (as secondary prevention).

Reduced serum vitamin D concentrations in healthy early-lactation dairy cattle

Cattle obtain vitamin D by ingestion or cutaneous exposure to UV light. Dairy cattle diets are frequently supplemented with vitamin D to compensate for limited sun exposure or during times of increased metabolic demands, such as the periparturient period, to maintain calcium homeostasis. Whether housing and supplemental vitamin D practices supply adequate amounts of vitamin D to optimally support the transition from gestation to lactation in dairy cattle is unknown. Our objective was to determine how serum vitamin D concentrations of dairy cows change with season, age, parity, and stage of lactation. Clinically healthy cows (n = 183) from 5 commercial dairies were enrolled in the study. Serum samples were collected at dry off, within 7 d of entering the close-up group, and within 7 d after calving (calving+7). Vitamin D status was determined by measuring serum 25-hydroxyvitamin D [25(OH)D] by radioimmunoassay. We performed repeated-measures mixed-effects linear regression to determine the effects of season, age, parity, and lactation stage (dry off, close-up, and calving+7) on 25(OH)D concentrations in serum. Bivariable analysis indicated that parity, age, and season were not associated with serum 25(OH)D concentrations. Sample period affected 25(OH)D concentrations, with the highest 25(OH)D levels at dry off (99.7 ± 1.9 ng/mL) followed by close up (93.8 ± 2.1 ng/mL), with the lowest levels at calving+7 (82.6 ± 1.7 ng/mL). These data showed a large depletion of 25(OH)D in dairy cattle postpartum compared with late prepartum, although the biological significance of this change in these healthy cattle is unclear. Consumption of serum 25(OH)D by immune system functions and calcium homeostasis in early lactation likely caused the reduction in serum 25(OH)D concentrations after calving. These results suggest that determining whether serum 25(OH)D concentrations are associated with the incidence of transition period disease is an appropriate next step. Assessing the effects of enhanced vitamin D supplementation of cows in early lactation on postpartum diseases may be warranted.

A 100-Year Review: From ascorbic acid to zinc—Mineral and vitamin nutrition of dairy cows

Mineral and vitamin nutrition of dairy cows was studied before the first volume of the Journal of Dairy Science was published and is still actively researched today. The initial studies on mineral nutrition of dairy cows were simple balance experiments (although the methods available at the time for measuring minerals were anything but simple). Output of Ca and P in feces, urine, and milk was subtracted from intake of Ca and P, and if values were negative it was often assumed that cows were lacking in the particular mineral. As analytical methods improved, more minerals were found to be required by dairy cows, and blood and tissue concentrations became primary response variables. Those measures often were poorly related to cow health, leading to the use of disease prevalence and immune function as a measure of mineral adequacy. As data were generated, mineral requirements became more accurate and included more sources of variation. In addition to milk yield and body weight inputs, bioavailability coefficients of minerals from different sources are used to formulate diets that can meet the needs of the cow without excessive excretion of minerals in manure, which negatively affects the environment. Milk, or more accurately the lack of milk in human diets, was central to the discovery of vitamins, but research into vitamin nutrition of cows developed slowly. For many decades bioassays were the only available method for measuring vitamin concentrations, which greatly limited research. The history of vitamin nutrition mirrors that of mineral nutrition. Among the first experiments conducted on vitamin nutrition of cows were those examining the factors affecting vitamin concentrations of milk. This was followed by determining the amount of vitamins needed to prevent deficiency diseases, which evolved into research to determine the amount of vitamins required to promote overall good health. The majority of research was conducted on vitamins A, D, and E because these vitamins have a dietary requirement, and clinical and marginal deficiencies became common as diets for cows changed from pasture and full exposure to the sun to stored forage and limited sun exposure. As researchers learned new functions of fat-soluble vitamins, requirements generally increased over time. Diets generally contain substantial amounts of B vitamins, and rumen bacteria can synthesize large quantities of many B vitamins; hence, research on water-soluble vitamins lagged behind. We now know that supplementation of specific water-soluble vitamins can enhance cow health and increase milk production in certain situations. Additional research is needed to define specific requirements for many water-soluble vitamins. Both mineral and vitamin research is hampered by the lack of sensitive biomarkers of status, but advanced molecular techniques may provide measures that respond to altered supply of minerals and vitamins and that are related to health or productive responses of the cow. The overall importance of proper mineral and vitamin nutrition is known, but as we discover new and more diverse functions, better supplementation strategies should lead to even better cow health and higher production.

Mechanical factors and vitamin D deficiency in schoolchildren with low back pain: biochemical and cross-sectional survey analysis.

ObjectiveThis study was designed to evaluate the role of vitamin D, muscle fatigue biomarkers, and mechanical factors in the progression of low back pain (LBP) in schoolchildren.BackgroundChildren and adolescents frequently suffer from LBP with no clear clinical causes, and >71% of schoolchildren aged 12–17 years will show at least one episode of LBP.Materials and methodsA total of 250 schoolchildren aged 12–16 years were randomly enrolled in this study. For all schoolchildren height, weight, percentage of daily sun exposure and and areas of skin exposed to sun, method of carrying the bag, and bag weight and type were recorded over a typical school week. Pain scores, physical activity (PA), LBP, serum vitamin 25(OH)D level, serum bone-specific alkaline phosphatase, creatine kinase (CK), and lactate dehydrogenase (LDH) activities and calcium (Ca) concentrations were estimated using prevalidated Pain Rating Scale, modified Oswestry Low Back Pain Disability Questionnaire, short-form PA questionnaire, and colorimetric and immunoassay techniques.ResultsDuring the period of October 2013–May 2014, LBP was estimated in 52.2% of the schoolchildren. It was classified into moderate (34%) and severe (18%). Girls showed a higher LBP (36%) compared with boys (24%). In schoolchildren with moderate and severe LBP significantly higher (P=0.01) body mass index, waist, hip, and waist-to-hip ratio measurements were observed compared with normal schoolchildren. LBP significantly correlated with less sun exposure, lower PA, sedentary activity (TV/computer use), and overloaded school bags. In addition, schoolchildren with severe LBP showed lower levels of vitamin 25(OH)D and Ca and higher levels of CK, LDH, and serum bone-specific alkaline phosphatase compared with moderate and healthy schoolchildren. Stepwise regression analysis revealed that age, gender, demographic parameters, PA, vitamin D levels, Ca, CK, and LDH associated with ~56.8%–86.7% of the incidence of LBP among schoolchildren.ConclusionIn children and adolescents, LBP was shown to be linked with limited sun exposure, inadequate vitamin D diets, adiposity, lower PA, sedentary lifestyles, vitamin 25 (OH) D deficiency, and lower levels of Ca, CK, and LDH.

Thick melanoma in Tuscany.

The epidemiologic trends of cutaneous melanoma are similar in several countries with a Western-type lifestyle, where there is a progressively increasing incidence and a low but not decreasing mortality - even increasing in selected cases, especially in the older age groups. Also in Tuscany there is a steady rise in the incidence with prevalence of in situ and invasive thin melanomas, with also an increase of thick melanomas. It is necessary to reduce the frequency of thick melanomas to reduce specific mortality. The objective of the current survey has been to compare, in the Tuscany population, by a case-case study, thin and thick melanoma cases, trying to find out those personal and tumor characteristics which may help to customize preventive interventions. The study included nine centers involved in the melanoma diagnosis. A consecutive series of incident invasive melanomas diagnosed in a period of about 18 months (July 2010 to December 2011) was collected and matched according in a ratio of one thick melanoma (cutoff thickness: 1 mm) every two thin melanomas. The investigators filled in a questionnaire on patients' self-reported sun exposure, way of melanoma detection, awareness and performance of self-skin examination, as well as propensity to prevention in general. The results of this survey confirm that older age and the lower education level are associated with a later detection. The habit of performing skin self-examination is crucial in the early diagnosis of thick melanoma. The results of this survey seem to suggest that population aged over 50 years, with few total and few atypical nevi, and limited sun exposure and burning are at higher risk of late diagnosis. It can be assumed that part of the population is not effectively reached by prevention campaigns because they do not recognize themselves as being at risk for skin cancers. In order to achieve a higher rate of early diagnosis of skin melanoma, a new strategy must be implemented. It could be useful to rethink educational campaigns - which seem to unintentionally leave out subjects more at risk for melanoma - and to renew the active involvement of the general practitioners.

Sunlight exposure increases vitamin D sufficiency in growing pigs fed a diet formulated to exceed requirements

Traditional confinement practices limit exposure to sunlight and vitamin D synthesis, and vitamin insufficiency occurs even with dietary supplementation. The aim of this study was to determine the effect of limited sun exposure on serum concentration of vitamin D and the expression of vitamin D synthesizing enzymes in the liver and kidney of pigs on a vitamin D sufficient diet. White-pigmented grower pigs (29.7 ± 2.3 kg) fed 15% CP diet ad libitum providing >1,200 IU vitamin D3/kg of feed were exposed to sunlight for 1 h each day at solar noon for 14 d at the spring equinox (March pigs, n = 10) or summer solstice (June pigs, n = 5) and again before slaughter in June (March pigs) and September (June pigs). Blood for the analysis of 25(OH)D was collected before and after sunlight exposure. Traditionally housed pigs served as controls. After initial sun exposure, blood samples were collected from June pigs daily for 5 d and weekly for 8 wk to determine vitamin D3 and 25(OH)D decay, respectively. Kidney and liver samples were collected from the June pigs at slaughter after sun exposure for analysis of messenger RNA expression of vitamin D binding protein and synthesizing/degrading enzymes. Average daily gain (ADG) was not influenced (P > 0.5) by sunlight exposure. June pigs had fewer days on feed, lower (P = 0.003) ADG and were slaughtered at a lighter (P < 0.001) weight. Exposure to sunlight increased (P < 0.001) 25(OH) vitamin D for all pigs. March pigs, obtained from a Midwest producer, had lower (P < 0.001) concentration of 25(OH)D than June pigs born on-farm. Initial sunlight exposure increased serum concentration of 25(OH)D in March pigs by 200% and June pigs by 67%. Serum concentration of vitamin D3 was decreased (P < 0.05) by 72 h with 25(OH)D decreased (P < 0.05) by wk 4 after exposure. Expression of vitamin D binding protein, vitamin D synthesizing CYP2R1, CYP27A1, CYP2D25, or degrading enzyme CYP24A1 were not influenced (P ≥ 0.19) by sunlight exposure. Expression of CYP27B1 was decreased (P = 0.04) in the kidney but tended to be increased (P = 0.06) in the liver after sun exposure. These results suggest limited sun exposure can efficiently increase serum concentration of vitamin D in growing pigs with varying levels of vitamin sufficiency. The lack of major changes in vitamin synthesizing enzymes suggests the 14-d exposure period did not saturate the capacity of slaughter-weight pigs to synthesize vitamin D.

Vitamin D and spinal cord injury: should we care?

Narrative review. This review provides an overview of the etiological factors and consequences of vitamin D insufficiency in relation to spinal cord injury (SCI) as well as important considerations for vitamin D supplementation. Montreal, Canada. Literature search. Vitamin D insufficiency is common in SCI individuals owing to the presence of many contributing factors including limited sun exposure and intake, use of medication and endocrine perturbations. Although there are several biological plausible mechanisms by which vitamin D may act upon musculoskeletal and cardiometabolic health, the impact of vitamin D insufficiency on such systems remains ill defined in SCI. In the absence of guidelines for the management of vitamin D insufficiency in this high-risk population and in an attempt to provide clinical guidance, considerations for vitamin D supplementation such as the type of vitamin D, dosing regimens and toxicity are discussed and tentative recommendations suggested with particular reference to issues faced by SCI patients. Although high rates of vitamin D insufficiency are encountered in SCI individuals, its consequences and the amount of vitamin D required to prevent insufficiency are still unknown, indicating a need for more intervention studies with well-defined outcome measures. Routine screening and monitoring of vitamin D as well as treatment of suboptimal status should be instituted in both acute and chronic setting. The close interactions between vitamin D and related bone minerals should be kept in mind when supplementing SCI individuals, and practices should be individualized with clinical conditions.