SOLAR ultraviolet radiation and vitamin D: a historical perspective

From molecular basis to clinical insights: a challenging future for the vitamin D endocrine system in colorectal cancer

Colorectal cancer (CRC) is one of the most life-threatening neoplasias in terms of incidence and mortality worldwide. Vitamin D deficiency has been associated with an increased risk of CRC. 1α,25-Dihydroxyvitamin D3 [1,25(OH)2 D3 ], the most active vitamin D metabolite, is a pleiotropic hormone that, through its binding to a transcription factor of the nuclear receptor superfamily, is a major regulator of the human genome. 1,25(OH)2 D3 acts on colon carcinoma and stromal cells and displays tumor protective actions. Here, we review the variety of molecular mechanisms underlying the effects of 1,25(OH)2 D3 in CRC, which affect multiple processes that are dysregulated during tumor initiation and progression. Additionally, we discuss the epidemiological data that associate vitamin D deficiency and CRC, and the most relevant randomized controlled trials of vitamin D3 supplementation conducted in both healthy individuals and CRC patients.

Highlighting nuances of blue light phototherapy: Mechanisms and safety considerations

The efficacy of blue light therapy in dermatology relies on numerous clinical studies. The safety remains a topic of controversy, where potentially deleterious effects were derived from in vitro rather than in vivo experiments. The objectives of this work were (1) to highlight the nuances behind "colors" of blue light, light propagation in tissue and the plurality of modes of action; and (2) to rigorously analyze studies on humans reporting both clinical and histological data from skin biopsies with focus on DNA damage, proliferation, apoptosis, oxidative stress, impact on collagen, elastin, immune cells, and pigmentation. We conclude that blue light therapy is safe for human skin. It induces intriguing skin pigmentation, in part mediated by photoreceptor Opsin-3, which might have a photoprotective effect against ultraviolet irradiation. Future research needs to unravel photochemical reactions and the most effective and safe parameters of blue light in dermatology.

Vitamin D status and its correlation to depression

BACKGROUND

Vitamin D can influence more than 200 genes in various tissues showing its credibility among the fat-soluble vitamins. Vitamin D deficiency is directly proportional to major clinical conditions such as cardiovascular diseases, diabetes, malignancy, and multiple sclerosis. This study was conducted to determine the vitamin D level of individuals and its association with depression.

METHODS

Vitamin D levels of 100 healthy and 100 depressed subjects were determined. The isolated subjects were screened on the Beck Depression Inventory (BDI) scale and divided into three groups according to their age. Group-I comprised subjects of age 20 years and below, Group-II included subjects of age 21 to 60, and Group-III comprised subjects of ≥ 61 years of age. A sufficient level of vitamin D in normal subjects was noted, while mild deficiency of vitamin D status was observed in depressed subjects.

RESULTS

Our study has reported a higher percentage of vitamin D deficiency in the Peshawar region. The results of our study indicated that depression was common in individuals having vitamin D deficiency.

CONCLUSIONS

The study showed a very high frequency of vitamin D deficiency in subjects with depression in Peshawar, Pakistan. The deficiency of vitamin D was observed more in females as compared to males. Further studies should explicate whether the highly widespread vitamin D deficiency could be cost-effectively treated as part of preventive or treatment interventions for depression.

Transcriptome analysis of molecular response to UVC irradiation in zebrafish embryos

Ultraviolet (UV) rays can be both harmful and beneficial to humans. This study aimed to investigate the toxicity and safety of ultraviolet C (UVC) exposure in living organisms and the corresponding biodefense molecular mechanisms. Zebrafish embryos, at an early developmental stage (5-6 h post-fertilization), were irradiated with increasing UVC dosages using high-efficiency deep-ultraviolet light-emitting diodes (278 nm). Morphological phenotypes including survival rate, hatching rate, heart rate, and malformation rate were evaluated. Compared to un-irradiated controls, all zebrafish embryos exposed to 4.5 mJ/cm² UVC survived and showed no significant difference in hatching and heart rate. However, 7.5 mJ/cm² of UVC irradiation caused a significantly decreased survival rate (37.5%) and an increased malformation rate (81.8%). Therefore, 4.5 mJ/cm² was chosen as the limit dosage that the internal biodefense system of zebrafish embryos can protect against UVC radiation. Transcriptome analysis (RNA sequencing) performed on 3 min and 3 days post-irradiation embryos (4.5 mJ/cm²) revealed the molecular mechanisms underlying the response of zebrafish embryos to irradiation. The embryos quickly responded to UVC-induced stress by activating the p53 signaling pathway. In addition, after 3 days of recuperation, the embryos showed activation of signal transducer and activator of transcription (STAT) signaling pathway. To our knowledge, this is the first study to evaluate the toxicological effects and the molecular mechanism of biodefense in zebrafish embryos upon 278 nm UVC irradiation.

National and subnational burden of disease attributable to occupational exposure to solar ultraviolet radiation (SUVR) in Iran, 2005-2019

Overexposure to solar ultraviolet radiation (SUVR) can cause skin and eye adverse effects for outdoor workers. In this study, the burden of disease induced by occupational exposure to SUVR and its spatiotemporal trend at national and sub-national levels in Iran, 2005-2019 were assessed. The attributable burden of disease was assessed using the following five datasets: (1) distribution of occupational exposure to SUVR, (2) total incidences and deaths of health outcomes of SUVR exposure, (3) population attributable fractions of the health outcomes of SUVR exposure, (4) age-gender distribution of outdoor workers, and (5) disability-adjusted life year (DALY) calculation constants. During 2005-2019, the attributable DALYs increased from 2442 to 2907 and the attributable DALY rate (per 100,000 workers) slightly decreased from 11.94 to 11.91. The share of YLL in the attributable burden of disease was in the range of 43%-46%. Out of nine causes, about 90% of the attributable burden of disease in 2019 was related to cataracts (29.9%), malignant skin melanoma (27.4%), squamous-cell carcinoma (18.6%), and sunburn (17.2%). During the study period, the attributable DALY rate in women increased by 60.95% (from 5.04 to 8.11) and in men decreased by 2.06% (from 13.03 to 12.76). The total attributable DALYs and DALY rate rose by age during 2005-2019. The contributions of population growth, risk-deleted DALY rates, exposure risk, and population age structure in temporal changes of the attributable burden of disease were 19.27%, 9.13%, -1.35%, and -14.8%, respectively. The three highest attributable DALY rates in 2019 were observed in South Khorasan (21.28), Chahar Mahal and Bakhtiari (17.42), and Kordestan (17.26), respectively. The preventive interventions against SUVR overexposure, regular screenings, and early treatments with an emphasis on occupations with continuous sun exposure and provinces with increasing attributable DALY rates should be considered in the occupational health action plan in the country.

Circulating 25-hydroxy-vitamin D and the risk of cardiovascular diseases. Systematic review and meta-analysis of prospective cohort studies

AIMS

Circulating vitamin D is linked with the risk of cardiovascular disease (CVD). A meta-analysis has yet to explicitly explore correlation between vitamin D and the risk of CVD incidence and recurrent CVD. This meta-analysis examines the association between 25-hydroxy-vitamin D (25(OH)D) and the risk of CVD incidence (fatal, non-fatal, fatal and non-fatal combined events) and the risk of recurrent CVD (fatal, recurrent, and fatal and recurrent combined events). PROSPERO registration-CRD42021251483.

DATA SYNTHESIS

A total of 79 studies (46 713 CVD cases in 1 397 831 participants) were included in the meta-analysis, of which 61 studies examined the risk of CVD incidence events, and 18 studies examined risk of recurrent CVD events. The risk of CVD incidence events (RR = 1.34, 95% CI: 1.26-1.43, p < 0.001) and recurrent CVD events (RR = 1.86, 95% CI: 1.46-2.36, p < 0.001) was higher in the lowest than the highest category of circulating 25(OH)D. Dose-response analysis reported a linear association for every 10 ng/ml increment of 25(OH)D and non-fatal CVD incidence events (RR = 0.94; 95% CI = 0.89-0.98, p = 0.005), lower fatal recurrent CVD events (RR = 0.45; 95% CI = 0.32-0.62, p < 0.001) and lower combined recurrent CVD events (RR = 0.80; 95% CI = 0.65-0.97, p = 0.023). A non-linear association was observed between higher 25(OH)D and lower fatal CVD incidence events (P-nonlinear<0.001), lower combined CVD incidence events (P-nonlinear = 0.001), and lower non-fatal recurrent CVD events (P-nonlinear = 0.044).

CONCLUSIONS

The lowest category of circulating 25(OH)D was associated with a higher risk of CVD incidence events and recurrent CVD events.

Vitamin D: Skin, sunshine, and beyond

Vitamin D is a steroid hormone of importance to the field of dermatology. Skin is unique in that it is the site of vitamin D synthesis upon sun exposure and a target organ for its activity. We explore the physiology and metabolic mechanism of action of vitamin D, as well as its effects on the skin. We also discuss the current evidence of the efficacy and safety of oral and topical vitamin D analogues on skin conditions such as psoriasis, atopic dermatitis, vitiligo, sunburn, actinic keratosis, and fibrosing skin disorders. Based on currently available scientific evidence, the National Academy of Medicine's recommended dietary allowance for vitamin D ranges from 400 IU to 800 IU daily based on age categories.

Spatiotemporal analysis of solar ultraviolet radiation based on Ozone Monitoring Instrument dataset in Iran, 2005-2019

The solar ultraviolet radiation (UVR) at national, provincial and county levels in Iran during 2005-2019 were determined based on Ozone Monitoring Instrument (OMI) dataset. The temporal (annual and monthly) trends and spatial distributions of the UVR in terms of erythemally weighted daily dose (EDD), erythemally weighted irradiance at local solar noon time (EDR), and UV index and the major factors influencing the spatiotemporal trends were analyzed. The population-weighted average values of EDD, EDR, and UV index in Iran were respectively 3631 J/m², 176.3 mW/m², 7.1 in 2005 and rose by 0.22% per year to 3744 J/m², 181.7 mW/m², and 7.3, respectively in 2019, but the annual trend was not statistically significant. The EDD in Iran during the study period exhibited the highest monthly average value in June (6339 J/m²) and the lowest one in December (1263 J/m²). The solar UVA/UVB ratios at the national level during 2005-2019 were considerably lower in summer. The EDD provincial average values in the study period were in the range of 2717 (Gilan) to 4424 J/m² (Fars). The spatiotemporal variations of the solar UVR parameters were well described by the linear models as a function of cloud optical thickness (COT), ozone column amount, surface albedo, latitude, and altitude (R² > 0.961, p value < 0.001) and the temporal changes of the solar UVR parameters were mainly caused by the COT. The results indicated that non-burning exposure to solar UVR in summer can be more efficient for vitamin D synthesis due to higher contribution of UVB in the solar UVR. The spatial distributions and temporal trends should be considered to determine the optimal duration, time and condition of exposure to the solar UVR for the public and occupational training and public health measures.

Investigating the Role of Functional Polymorphism of Maternal and Neonatal Vitamin D Binding Protein in the Context of 25-Hydroxyvitamin D Cutoffs as Determinants of Maternal-Neonatal Vitamin D Status Profiles in a Sunny Mediterranean Region

Recent results indicate that dysregulation of vitamin D-binding protein (VDBP) could be involved in the development of hypovitaminosis D, and it comprises a risk factor for adverse fetal, maternal and neonatal outcomes. Until recently, there was a paucity of results regarding the effect of maternal and neonatal VDBP polymorphisms on vitamin D status during pregnancy in the Mediterranean region, with a high prevalence of hypovitaminosis D. We aimed to evaluate the combined effect of maternal and neonatal VDBP polymorphisms and different maternal and neonatal 25-hydroxyvitamin D (25(OH)D) cut-offs on maternal and neonatal vitamin D profile. Blood samples were obtained from a cohort of 66 mother–child pairs at birth. Our results revealed that: (i) Maternal VDBP polymorphisms do not affect neonatal vitamin D status at birth, in any given internationally adopted maternal or neonatal cut-off for 25(OH)D concentrations; (ii) neonatal VDBP polymorphisms are not implicated in the regulation of neonatal vitamin D status at birth; (iii) comparing the distributions of maternal VDBP polymorphisms and maternal 25(OH)D concentrations, with cut-offs at birth, revealed that mothers with a CC genotype for rs2298850 and a CC genotype for rs4588 tended to demonstrate higher 25(OH)D (≥75 nmol/L) during delivery (p = 0.05 and p = 0.04, respectively), after adjustments for biofactors that affect vitamin D equilibrium, including UVB, BMI and weeks of gestation. In conclusion, this study from Southern Europe indicates that maternal and neonatal VDBP polymorphisms do not affect neonatal vitamin D status at birth, whereas mothers with CC genotype for rs2298850 and CC genotype for rs4588 demonstrate higher 25(OH)D concentrations. Future larger studies are required to establish a causative effect of these specific polymorphisms in the attainment of an adequate (≥75 nmol/L) maternal vitamin D status during pregnancy.

Prevalence of hyperhomocysteinaemia, selected determinants and relation to hypertension severity in Northern-Nigerian hypertensives: the ABU homocysteine survey

Background

This study aimed at evaluating the prevalence of hyperhomocysteinaemia in Northern-Nigerian hypertensives and its association with hypertension severity and some major determinants as data regarding these are lacking in sub-Saharan Africa.

Method

A Community-based cross-sectional study done on 120 randomly-selected hypertensive patients who responded to an ABU radio frequency modulated invitation for free health-screening at the Ahmadu Bello University (ABU) Medical Centre from January 2016 to June 2016. The percentage of participants with high homocysteine levels, their anthropometric parameters and blood pressures were determined. Plasma homocysteine (hcy) was classified as normal (5–15), moderate (>15–30), intermediate (31–100) and severe (>100) µmol/L. Kruskal-Wallis test was applied and log-transformed homocysteine (Ln₁₀Homocysteine) was correlated with systolic and diastolic blood pressures as well as age, body mass index, fasting blood glucose, glomerular filtration rate, hypertension duration and Ln₁₀folate in males and females using the Pearson's Correlation analysis.

Results

There were 83(69.2%) females and 37(30.8%) males with Median homocysteine of 20.8 µmol/L and 22.0 µmol/L respectively (p=0.003). Hyperhomocysteinaemia was found in 118(98.3%) hypertensives while 2(1.7%) subjects had normo-homocysteinaemia. Moderate hyperhomocysteinaemia (Median, 20.8 µmol/L) was identified in 105(87.5%) and intermediate (Median, 40 µmol/L) in 13(10.8%) (p<0.001). No subject had severe hyperhomocysteinaemia. Homocysteine was higher (p=0.003) in subjects with Stage 2 systolic hypertension. Ln₁₀Homocysteine was significantly (p<0.001) correlated with blood pressure (SBP: r=0.45; DBP: r=0.40) and age (r=0.33).

Conclusion

The prevalence of hyperhomocysteinaemia in North-Western Nigerian hypertensives is high as against normal healthy controls. Plasma homocysteine is higher with severe systolic hypertension and positively associated with age.

Funding

No specific grants but Micro Nova Pharmaceuticals Limited, Nigeria and Emzor Pharmaceutical Industries, Lagos, Nigeria supported with drugs.

Modern Synthetic Methods for the Stereoselective Construction of 1,3-Dienes

The 1,3-butadiene motif is widely found in many natural products and drug candidates with relevant biological activities. Moreover, dienes are important targets for synthetic chemists, due to their ability to give access to a wide range of functional group transformations, including a broad range of C-C bond-forming processes. Therefore, the stereoselective preparation of dienes have attracted much attention over the past decades, and the search for new synthetic protocols continues unabated. The aim of this review is to give an overview of the diverse methodologies that have emerged in the last decade, with a focus on the synthetic processes that meet the requirements of efficiency and sustainability of modern organic chemistry.

Solar UV Radiation in the Tropics: Human Exposure at Reunion Island (21° S, 55° E) during Summer Outdoor Activities

Reunion Island is a popular tourist destination with sandy beaches, an active volcano (Piton de la Fournaise), and Piton des Neiges, the highest and most dominant geological feature on the island. Reunion is known to have high levels of solar ultraviolet radiation (UVR) with an ultraviolet index (UVI) which can reach 8 in winter and 16 in summer (climatological conditions). UVR has been linked to skin cancer, melanoma, and eye disease such as cataracts. The World Health Organization (WHO) devised the UVI as a tool for expressing UVR intensity. Thresholds ranging from low (UVI 1-2) to extreme (UVI > 11) were defined depending on the risk to human health. The purpose of the study was to assess UVR exposure levels over three of the busiest tourist sites on the island. UVR was measured over several hours along popular hiking trails around Piton de la Fournaise (PDF), Piton des Neiges (PDN), and St-Leu Beach (LEU). The results were compared with those recorded by the local UV station at Saint-Denis. In addition, cumulative standard erythemal dose (SED) was calculated. Results showed that UVI exposure at PDF, PDN, and LEU were extreme (>11) and reached maximum UVI levels of 21.1, 22.5, and 14.5, respectively. Cumulative SEDs were multiple times higher than the thresholds established by the Fitzpatrick skin phototype classification. UVI measurements at the three study sites showed that Reunion Island is exposed to extreme UVR conditions. Public awareness campaigns are needed to inform the population of the health risks related to UVR exposure.

Children of the Sun: a historical look at how pediatric light therapy shaped attitudes and behaviors toward sunbathing

Today, parents are warned to protect their children from the sun's ultraviolet (UV) rays, the most preventable and leading cause of skin cancer. Yet, during the first half of the 20th century, the medical community widely extolled the health benefits of daily sunbaths for babies and children. What initially had begun as evidence-based medical therapies to prevent pediatric diseases, specifically tuberculosis and rickets, soon took on a life of its own as physicians, public health experts, and the general public embraced sunbathing and tanning as a means to ensure health and wellbeing for children and families. Here, we trace how specific medical therapies entered mainstream pediatric medicine and, converging with societal and cultural forces, shaped attitudes and behaviors towards sunbathing that still exist today. Understanding our complex history with the sun may shed light on the current peak of skin cancer incidence and future disease development. Moreover, it may help improve how we educate parents and children about sun safety by taking into account the current social and cultural context of medical practice and health communication.

Subsistence fish consumption in rural Alaska: Using regional monitoring data to evaluate risk and bioavailability of dietary methylmercury

On average, Alaskans in rural communities consume over three times the Federally recommended maximum weekly fish ingestion rate (IR), the overwhelming majority of which is Pacific salmon. Results of statewide monitoring efforts consistently show that Pacific salmon from Alaska have low concentrations of mercury, yet concerns regarding dietary exposure to methylmercury (MeHg) and other aquatic contaminants continue to contribute to declining subsistence fish consumption rates in rural communities. Therefore, the goal of the present study was to use statewide biomonitoring datasets and regional fish IRs to quantitatively evaluate potential risk from dietary MeHg exposure via subsistence consumption of salmon from Alaska. Hazard Indices (HIs) did not exceed 1 for any of the groups evaluated, indicating negligible risk for the average Alaskan subsistence consumer. Selenium health benefit values (HBV_Se) of various fish species from AK were also calculated, with positive results for all commonly consumed subsistence species. Additionally, mercury concentrations in the hair of Alaskan women were evaluated as a proxy for dietary MeHg exposure. Results reveal that Alaskan women of childbearing age have substantially lower hair Hg concentrations than their counterparts in other large-scale biomonitoring studies, despite similar fish IRs. Collectively, results of the present study suggest that MeHg in Pacific salmon does not pose an unacceptable hazard for the average subsistence consumer in Alaska.

Low systemic vitamin D as a potential risk factor in primary open-angle glaucoma: a review of current evidence

Currently, intraocular pressure is the only modifiable risk factor for glaucoma; thus, identifying other modifiable determinants may have far-reaching outcomes. There has been increasing interest in vitamin D status and glaucoma pathogenesis as low vitamin D has been identified by some studies as an independent risk factor for glaucoma. Although the exact mechanism of vitamin D in glaucoma remains uncertain, there is sufficient evidence to continue research in this area. There is a potential physiological role for vitamin D as an anti-inflammatory agent in the oxidative stress-driven pathogenesis of primary open-angle glaucoma, and further studies are required to evaluate the temporal and causal relationship. Ocular vitamin D status in the tear, aqueous and vitreous fluid is a prospective gap in research.

UVB Irradiation Induced Cell Damage and Early Onset of Junbb Expression in Zebrafish

Ultraviolet B (UVB) radiation has drawn more attention over these past few decades since it causes severe DNA damage and induces inflammatory response. Serial gene profiling and high throughput data in UVB-associated phenomenon in human cultured cells or full rack of human skin have been investigated. However, results using different tissue models lead to ambiguity in UVB-induced pathways. In order to systematically understand the UVB-associated reactions, the zebrafish model was used, and whole organism gene profiling was performed to identify a novel biomarker which can be used to generate a new mechanistic approach for further screening on a UVB-related system biology. In this study, detailed morphological assays were performed to address biological response after receiving UVB irradiation at morphological, cellular, and molecular levels. Microarray screening and whole genome profiling revealed that there is an early onset expression of junbb in zebrafish embryos after UVB irradiation. Also, the identified novel biomarker junbb is more sensitive to UVB response than mmps which have been used in mouse models. Moreover, cellular and molecular response chronology after UVB irradiation in zebrafish provide a solid and fundamental mechanism for use in a UV radiation-associated study in the future.

Dietary Intake of Vitamin D from Dairy Products Reduces the Risk of Osteoporosis

Background: Vitamin D and calcium are important dietary compounds that affect bone mass, even if other minerals (potassium, zinc, etc.) and vitamins (A, C and K) are also involved. Vitamin D and certain minerals, in fact, play an important role in calcium homeostasis and calcium absorption. Hip fracture incidence is higher in Europe and the United States, where calcium is frequently included in the human diet; while the occurrence of these fractures is lower in developing countries, where diets are often poor in calcium. This condition is named the “calcium paradox”, and may be partially explained by phosphate toxicity, which can negatively affect mineral metabolism. It is important to maintain correct dietary calcium-phosphate balance in order to have a healthy life, reducing the risk of osteoporotic fractures in older people. Vitamin D can also act as a hormone; vitamin D2 (ergocalciferol) is derived from the UV-B radiation of ergosterol, the natural vitamin D precursor detected in plants, fungi, and invertebrates. Vitamin D3 (cholecalciferol) is synthesized by sunlight exposure from 7-dehydrocholesterol, a precursor of cholesterol that can also act as provitamin D3. Dietary intake of vitamin D3 is essential when the skin is exposed for short periods to ultraviolet B light (UV-B), a category of invisible light rays such as UV-A and UV-C. This can be considered the usual situation in northern latitudes during the winter season, or the typical lifestyle for older people and/or for people with very white delicate skin. The actual recommended daily intake of dietary vitamin D is strictly correlated with age, ranging from 5 μg for infants, children, teenagers, and adults—including pregnant and lactating women—to 15 μg for people over 65 years.

Children's Health in the Digital Age

Environmental studies, metabolic research, and state of the art research in neurobiology point towards the reduced amount of natural day and sunlight exposure of the developing child, as a consequence of increasingly long hours spent indoors online, as the single unifying source of a whole set of health risks identified worldwide, as is made clear in this review of currently available literature. Over exposure to digital environments, from abuse to addiction, now concerns even the youngest (ages 0 to 2) and triggers, as argued on the basis of clear examples herein, a chain of interdependent negative and potentially long-term metabolic changes. This leads to a deregulation of the serotonin and dopamine neurotransmitter pathways in the developing brain, currently associated with online activity abuse and/or internet addiction, and akin to that found in severe substance abuse syndromes. A general functional working model is proposed under the light of evidence brought to the forefront in this review.

Use of smartphone apps to monitor human exposure to solar radiation: Comparison between predicted and measured UV index values

The Ultra-Violet Index (UVI) is widespread used to communicate the UV radiation intensity to the general public. The knowledge of the UVI value and of its daily variation is essential for many techniques for monitoring the personal exposure to UV radiation. The UVI values are usually provided by the meteorological services and nowadays it is very common to find UVI forecast tools even in smartphone apps. In this paper, with the aim to evaluate the prediction accuracy of six smartphone apps, a measurement campaign of UVI has been carried out. The measurements have been conducted for the site of Pisa (central Italy), using a portable photoradiometer equipped with a UV erythemal irradiance probe (operating range 250-400 nm). The measured UVI values have been compared with the predicted UVI values (using smartphone apps). Bland-Altman and Passing-Bablok methods have been used to compare the data, the comparison has been conducted on the basis of 90 different UVI measurements, taken at different times, different days and different sky conditions. From the comparison between measured and predicted UVI values it has been possible to observe a general poor accuracy of the apps. The percentage deviations between measured and predicted UVI values were quite high and only one app was able to predict more than 70% of the measured data with an average percentage deviation lower than 30%.

Genetic, environmental and biomarker considerations delineating the regulatory effects of vitamin D on central nervous system function

Studies show that vitamin D (vit-D) (25(OH)D), the bioactive metabolite (1,25(OH)2D3) and vit-D receptors (vit-D receptor; protein disulphide isomerase, family A member 3) are expressed throughout the brain, particularly in regions pivotal to learning and memory. This has led to the paradigm that avoiding vit-D deficiency is important to preserve cognitive function. However, presently, it is not clear if the common clinical measure of serum 25(OH)D serves as a robust surrogate marker for central nervous system (CNS) homeostasis or function. Indeed, recent studies report CNS biosynthesis of endogenous 25(OH)D, the CNS expression of the CYP group of enzymes which catalyse conversion to 1,25(OH)2D3 and thereafter, deactivation. Moreover, in the periphery, there is significant ethnic/genetic heterogeneity in vit-D conversion to 1,25(OH)2D3 and there is a paucity of studies which have actually investigated vit-D kinetics across the cerebrovasculature. Compared with peripheral organs, the CNS also has differential expression of receptors that trigger cellular response to 1,25(OH)2D3 metabolites. To holistically consider the putative association of peripheral (blood) abundance of 25(OH)D on cognitive function, herein, we have reviewed population and genetic studies, pre-clinical and clinical intervention studies and moreover have considered potential confounders of vit-D analysis.

Prevalence and Risk Factors of Hypovitaminosis-D in Children with Cognitive and Movement Disorders

OBJECTIVES

To document the prevalence of hypovitaminosis-D in children with intellectual and movement disorders and to identify the risk factors in vitamin D deficient children.

METHODS

This is a cross-sectional study on 90 children with neurodevelopmental disabilities. The prevalence of hypovitaminosis-D and the risk factors such as sun exposure, age-appropriate mobility, diet, skin color and anti-epileptic medications were examined in children with cognitive disorders and movement disorders.

RESULTS

The mean serum vitamin D level in children with cognitive disability (n = 46) was found to be 26.7 ± 16.3 ng/L and in the children with movement disability (n = 44) it was 27.9 ± 10.5 ng/L. Though the risk factors were found in greater numbers in children in the deficient group (vitamin D < 30 ng/L), the difference between the two groups was not significant. Of the 90 children, 86 (95.5%) had at least one sign of vitamin D deficiency. Lowest levels of vitamin D were seen in autistic spectrum disorder and learning disabilities in the Cognitive Disability group and hemiplegia in the Movement Disability group.

CONCLUSIONS

The prevalence of vitamin D deficiency in children with neurodevelopmental disabilities was 72.2%, with 76.1% in the cognitive disability group and 68.2% in the movement disability group. The risk factors were more common in vitamin D deficient children.

A comparison of the effect of supplementation and sunlight exposure on serum vitamin D and parathyroid hormone: A systematic review and meta-analysis

Background: Supplementation and getting sunlight exposure are two treatments for vitamin D deficiency. However, studies reported conteroversial findings regarding the efficacy of these two methods.Objective: To compare the effect of oral vitamin D supplementation with sunlight exposure on serum vitamin D and parathyroid hormone (PTH).Methods: A computer-based literature search through PubMed, Scopus and Google scholar search engines was conducted until April 2019 to find clinical trials which compared the effect of oral vitamin D supplementation with sunlight exposure on serum vitamin D and PTH. Means for serum 25-hydroxy vitamin D3 (25(OH) D3) and PTH concentration were extracted. A subgroup analysis was used to detect potential sources of inter-study heterogeneity. Mean differences (MD) were analyzed using a random-effects model (the DerSimonian-Laird approach).Results: A total of seven papers were included in the meta-analysis. Pooled analysis showed that vitamin D supplementation significantly elevated levels of serum 25(OH) D3 in comparison with sunlight exposure (MD: 8.56nmol/l, 95%CI: 4.15, 12.97, T² = 40.32%, H² = 9.45%, P for heterogeneity p < 0.001). Also, the difference between the effect of vitamin D supplementation and sun exposure was lower in studies which used UVB radiation compared with studies which applied direct sunlight (MD: 11.65 nmol/l, 95%CI: 7.02, 16.28; P for between subgroup heterogeneity = 0.001).Conclusion: Vitamin D supplementation was more effective than sun exposure at increasing serum 25(OH) D3. The difference between efficacy of vitamin D supplementation and sun exposure was lower in studies which used long-term sun exposure or applied UVB treatment instead of direct sunlight.

Vitamin D testing and treatment: a narrative review of current evidence

Vitamin D testing and treatment is a subject of controversial scientific discussions, and it is challenging to navigate through the expanding vitamin D literature with heterogeneous and partially opposed opinions and recommendations. In this narrative review, we aim to provide an update on vitamin D guidelines and the current evidence on the role of vitamin D for human health with its subsequent implications for patient care and public health issues. Vitamin D is critical for bone and mineral metabolism, and it is established that vitamin D deficiency can cause rickets and osteomalacia. While many guidelines recommend target serum 25-hydroxyvitamin D (25[OH]D) concentrations of ≥50 nmol/L (20 ng/mL), the minimum consensus in the scientific community is that serum 25(OH)D concentrations below 25-30 nmol/L (10-12 ng/mL) must be prevented and treated. Using this latter threshold of serum 25(OH)D concentrations, it has been documented that there is a high worldwide prevalence of vitamin D deficiency that may require public health actions such as vitamin D food fortification. On the other hand, there is also reason for concern that an exploding rate of vitamin D testing and supplementation increases costs and might potentially be harmful. In the scientific debate on vitamin D, we should consider that nutrient trials differ from drug trials and that apart from the opposed positions regarding indications for vitamin D treatment we still have to better characterize the precise role of vitamin D for human health.

Vitamin D for skeletal and non-skeletal health: What we should know

Vitamin D plays an essential role in regulating calcium and phosphate metabolism and maintaining a healthy mineralized skeleton. Humans obtain vitamin D from sunlight exposure, dietary foods and supplements. There are two forms of vitamin D: vitamin D₃ and vitamin D₂. Vitamin D₃ is synthesized endogenously in the skin and found naturally in oily fish and cod liver oil. Vitamin D₂ is synthesized from ergosterol and found in yeast and mushrooms. Once vitamin D enters the circulation it is converted by 25-hydroxylase in the liver to 25-hydroxyvitamin D [25(OH)D], which is further converted by the 25-hydroxyvitamin D-1α-hydroxylase in the kidneys to the active form, 1,25-dihydroxyvitamin D [1,25(OH)₂D]. 1,25(OH)₂D binds to its nuclear vitamin D receptor to exert its physiologic functions. These functions include: promotion of intestinal calcium and phosphate absorption, renal tubular calcium reabsorption, and calcium mobilization from bone. The Endocrine Society's Clinical Practice Guideline defines vitamin D deficiency, insufficiency, and sufficiency as serum concentrations of 25(OH)D of <20 ng/mL, 21-29 ng/mL, and 30-100 ng/mL, respectively. Vitamin D deficiency is a major global public health problem in all age groups. It is estimated that 1 billion people worldwide have vitamin D deficiency or insufficiency. This pandemic of vitamin D deficiency and insufficiency is attributed to a modern lifestyle and environmental factors that restrict sunlight exposure, which is essential for endogenous synthesis of vitamin D in the skin. Vitamin D deficiency is the most common cause of rickets and osteomalacia, and can exacerbate osteoporosis. It is also associated with chronic musculoskeletal pain, muscle weakness, and an increased risk of falling. In addition, several observational studies observed the association between robust levels of serum 25(OH)D in the range of 40-60 ng/mL with decreased mortality and risk of development of several types of chronic diseases. Therefore, vitamin D-deficient patients should be treated with vitamin D₂ or vitamin D₃ supplementation to achieve an optimal level of serum 25(OH)D. Screening of vitamin D deficiency by measuring serum 25(OH)D is recommended in individuals at risk such as patients with diseases affecting vitamin D metabolism and absorption, osteoporosis, and older adults with a history of falls or nontraumatic fracture. It is important to know if a laboratory assay measures total 25(OH)D or only 25(OH)D₃. Using assays that measure only 25(OH)D₃ could underestimate total levels of 25(OH)D and may mislead physicians who treat patients with vitamin D₂ supplementation.

Comparison of vitamin D metabolites in wild and captive baboons

Vitamin D adequacy is essential for multiple physiologic processes. With limited exposure to sunlight for vitamin D3 synthesis, captive primates are supplemented with vitamin D3 (cholecalciferol). Vitamin D metabolite data from wild primates living indigenously could suggest optimum levels. The purpose of this study was to: 1) to explore whether baboons, a speciose genus whose members have significant exposed skin, coat color variation and wide geographical distribution, mirrors the skin pigmentation-vitamin D relationship found in humans; 2) compare vitamin D metabolite levels in wild and captive members of the same or similar baboon species; and 3) apply a recently developed method currently used in humans for measuring multiple vitamin D metabolites as a panel to explore if/how these metabolites can inform us on vitamin D sufficiency. Serum samples from males of three baboon species in the wild: Papio anubis (olive baboon, dark exposed skin), P. cynocephalus (yellow baboon, brown exposed skin), and P. hamadryas (hamadryas baboon, pink exposed skin), were compared with vitamin D supplemented captive olive baboons with sun exposure. Liquid chromatography/tandem mass spectrometry (LC/MS/MS) measured vitamin D and its main metabolites. Cholecalciferol, 25 hydroxyvitamin D2&3 (25(OH)D2&3 ), and 24,25 dihydroxyvitamin D2&3 (24,25(OH)2 D2&3 ), showed significant differences by species. The levels of cholecalciferol due to supplements in the captive olive baboons did not convert to higher 25(OH)D3 while the wild olive baboons exhibited the lowest levels for both cholecalciferol and 25(OH)D3 . Further metabolic conversion of 25(OH)D3 to 24,25(OH)2 D3 indicated that all baboons had more similar conversion ratios and these were within the same range found for humans that are depicted as having adequate vitamin D levels. This study provided evidence that exposed skin color does influence vitamin D3 levels, with lower levels in darker skinned species, but these differences are eliminated in the downstream metabolite conversion indicating strong regulatory control.

Adiponectin and vitamin D-binding protein are independently associated at birth in both mothers and neonates

CONTEXT

Adult body fat is associated with birth anthropometry, suggesting a role for metabolic regulators including vitamin D and the adipokines-adiponectin and irisin-which have been reported to interact but, as yet, data remain controversial.

OBJECTIVE

To study (i) the relationship between vitamin D, its binding protein (VDBP) and the adipokines, adiponectin, and irisin in mothers and neonates at birth and (ii) their effects on neonate anthropometric outcomes.

DESIGN

Cross-sectional study for healthy mothers with full-term and uncomplicated births.

SETTING

Primary care.

SUBJECTS

Seventy pairs of newly delivered neonates and their mothers.

MAIN OUTCOMES FEATURES

Biochemical markers from maternal and cord: VDBP, adiponectin, irisin, calcium, albumin, parathyroid hormone, 25OHD, 1,25(OH)₂D. Maternal demographic and social characteristics and neonate anthropometric parameters were recorded.

RESULTS

Maternal VDBP levels (364.1 ± 11.9 μg/ml) demonstrated a strong positive correlation with maternal adiponectin (4.4 ± 0.4 μg/ml) and irisin (308.8 ± 50.8 ng/ml) concentrations, which remained significant (p < 0.001 and p < 0.041, respectively) after adjustment with multiple parameters, including weeks of gestation, maternal age, and BMI. The finding of a strong association of VDBP (355.3 ± 29.2 μg/ml) and adiponectin (11.9 ± 2.0 μg/ml) but not irisin (174.4 ± 26.0 ng/ml) was also evident in neonates (p = 0.03 and p = 0.94, respectively). No association was observed in both maternal and neonatal vitamin D, adiponectin, and irisin.

CONCLUSIONS

The main findings of this study are (i) the perspective of a potential independent interaction of VDBP and adiponectin in both mothers and neonates and (ii) the lack of a causative model effect of both maternal/neonatal vitamin D status and adipokine profile on neonatal anthropometry at birth, as a surrogate marker of future metabolic health of the offspring.

Rickets

Rickets is a bone disease associated with abnormal serum calcium and phosphate levels. The clinical presentation is heterogeneous and depends on the age of onset and pathogenesis but includes bowing deformities of the legs, short stature and widening of joints. The disorder can be caused by nutritional deficiencies or genetic defects. Mutations in genes encoding proteins involved in vitamin D metabolism or action, fibroblast growth factor 23 (FGF23) production or degradation, renal phosphate handling or bone mineralization have been identified. The prevalence of nutritional rickets has substantially declined compared with the prevalence 200 years ago, but the condition has been re-emerging even in some well-resourced countries; prematurely born infants or breastfed infants who have dark skin types are particularly at risk. Diagnosis is usually established by medical history, physical examination, biochemical tests and radiography. Prevention is possible only for nutritional rickets and includes supplementation or food fortification with calcium and vitamin D either alone or in combination with sunlight exposure. Treatment of typical nutritional rickets includes calcium and/or vitamin D supplementation, although instances infrequently occur in which phosphate repletion may be necessary. Management of heritable types of rickets associated with defects in vitamin D metabolism or activation involves the administration of vitamin D metabolites. Oral phosphate supplementation is usually indicated for FGF23-independent phosphopenic rickets, whereas the conventional treatment of FGF23-dependent types of rickets includes a combination of phosphate and activated vitamin D; an anti-FGF23 antibody has shown promising results and is under further study.

Chemical Characterization and Antioxidant Potential of Wild Ganoderma Species from Ghana

The chemical characterization and antioxidant potential of twelve wild strains of Ganoderma sp. from Ghana, nine (LS1-LS9) of which were found growing wild simultaneously on the same dying Delonix regia tree, were evaluated. Parameters evaluated included the nutritional value, composition in sugars, fatty acids, phenolic and other organic compounds and some vitamins and vitamin precursors. Antioxidant potential was evaluated by investigating reducing power, radical scavenging activity and lipid peroxidation inhibition using five in vitro assays. Protein, carbohydrate, fat, ash and energy contents ranged between 15.7-24.5 g/100 g·dw, 73.31-81.90 g/100 g, 0.48-1.40 g/100 g, 0.68-2.12 g/100 g ash and 396.1-402.02 kcal/100 g, respectively. Fatty acids such as linoleic, oleic and palmitic acids were relatively abundant. Free sugars included rhamnose, fructose, mannitol, sucrose and trehalose. Total tocopherols, organic acids and phenolic compounds' content ranged between 741-3191 µg/100 g, 77-1003 mg/100 g and 7.6-489 µg/100 g, respectively. There were variations in the β-glucans, ergosterol and vitamin D₂ contents. The three major minerals in decreasing order were K > P > S. Ganoderma sp. strain AM1 showed the highest antioxidant activity. This study reveals, for the first time, chemical characteristics of Ganoderma spp. which grew simultaneously on the same tree.

Serum Vitamin D Concentrations in Baboons (Papio spp.) during Pregnancy and Obesity

Obesity is associated with vitamin D deficiency, which can lead to serious problems during pregnancy. However, the mechanisms of the deficiency and guidelines for vitamin D supplementation during pregnancy are not established yet, and variations in environmental exposures combined with the difficulties of performing research in pregnant women are obstacles in the evaluation of vitamin D metabolism. Baboons (Papio spp.) are an excellent, well-established model for reproductive research and represent a unique opportunity to study vitamin D metabolism in a controlled environment. This study used secondary data and specimen analysis as well as a novel experimental design to evaluate pregnant and nonpregnant baboons that were or were not exposed to sunlight while they were obese and after weight reduction. Daily D3 intake was 71% higher in nonpregnant obese baboons than in their nonobese counterparts, but serum vitamin D concentrations did not differ between these populations. In addition, serum 25-hydroxyvitamin D concentrations correlated negatively with the obesity index. This report is the first to show the effect of obesity and pregnancy on vitamin D concentrations in a NHP population. These data underline the importance of adequate vitamin D supplementation in obese animals.

Sunshine and vitamin D

Vitamin D is vital for bone health and its deficiency deemed as a disease of the past has re-emerged as an important health concern. Exposure of the skin to solar ultraviolet B radiation is the major source of vitamin D and only a small proportion is derived from dietary intake. We review the various factors that influence the cutaneous synthesis of vitamin D and the recommendations regarding safe sun exposure and dietary supplementation to achieve adequate vitamin D levels proposed for optimal bone health.

The role of geographical ecological studies in identifying diseases linked to UVB exposure and/or vitamin D

Using a variety of approaches, researchers have studied the health effects of solar ultraviolet (UV) radiation exposure and vitamin D. This review compares the contributions from geographical ecological studies with those of observational studies and clinical trials. Health outcomes discussed were based on the author's knowledge and include anaphylaxis/food allergy, atopic dermatitis and eczema, attention deficit hyperactivity disorder, autism, back pain, cancer, dental caries, diabetes mellitus type 1, hypertension, inflammatory bowel disease, lupus, mononucleosis, multiple sclerosis, Parkinson disease, pneumonia, rheumatoid arthritis, and sepsis. Important interactions have taken place between study types; sometimes ecological studies were the first to report an inverse correlation between solar UVB doses and health outcomes such as for cancer, leading to both observational studies and clinical trials. In other cases, ecological studies added to the knowledge base. Many ecological studies include other important risk-modifying factors, thereby minimizing the chance of reporting the wrong link. Laboratory studies of mechanisms generally support the role of vitamin D in the outcomes discussed. Indications exist that for some outcomes, UVB effects may be independent of vitamin D. This paper discusses the concept of the ecological fallacy, noting that it applies to all epidemiological studies.

Vitamin D and respiratory tract infections in childhood

BACKGROUND

Respiratory tract infections (RTIs) remain among of the most important causes of morbidity and mortality among children. Several studies have associated vitamin D deficiency with an increased risk of RTIs, and vitamin D supplementation has been proposed as a possible preventive measure against RTIs in children. The main aim of this review is to summarize the current evidence from the literature about the link between vitamin D and RTIs in children.

DISCUSSION

Several recent studies have shown that vitamin D has different immunomodulatory properties associated with the risk of RTIs in childhood. In this regard, it is very important to understand the definition of deficiency and insufficiency of vitamin D and when and how to treat this condition. Unfortunately, there is no consensus, although a level of at least 10 ng/mL 25-hydroxycholecalciferol (25[OH]D) is thought to be necessary to promote bone mineralization and calcium homeostasis, and a concentration between 20 ng/mL and 50 ng/mL is considered adequate to provide an immunomodulatory effect. Available data support a role for vitamin D deficiency in the risk of pediatric tuberculosis, recurrent acute otitis media, and severe bronchiolitis, whereas further studies are needed to confirm an association in children with recurrent pharyngotonsillitis, acute rhinosinusitis and community-acquired pneumonia.

CONCLUSIONS

Maintenance of adequate vitamin D status may be an effective and inexpensive prophylactic method against some RTIs, but the supplementation regimen has not been clearly defined. Further clinical trials are needed to determine the 25(OH)D concentrations associated with an increased risk of RTIs and optimal vitamin D supplementation regimen according to the type of RTI while also taking into consideration vitamin D receptor polymorphisms.

Investigation of multiple factors which may contribute to vitamin D levels of bedridden pregnant women and their preterm neonates

OBJECTIVE

25-Hydroxyvitamin D (25-OH-D) is the marker, which indicates vitamin D levels. The aim of this study was to investigate the possible factors, which contribute to serum 25-OH-D levels in bedridden mothers and their preterm neonates.

METHODS

Twenty-six preterm neonates born during the period of 24-33 weeks of gestational age and 20 mothers (who experienced pregnancy complications) were recruited to the study.

RESULTS

Five major results were obtained. (i) The 25-OH-D serum levels for preterm neonates and their mothers were found to possess strong correlation (ii) and both differed significantly in comparison with the optimal levels. (iii) An increase of mothers' 25-OH-D serum levels was associated with an increased possibility that the neonates would be measured to have normal 25-OH-D levels. (iv) Sex was not a key factor to neonates' 25-OH-D levels. (v) No correlation was found between mothers' 25-OH-D levels and their vitamin D3 supplement (400 IU/d during pregnancy).

CONCLUSIONS

Due to insufficient exposure to sunlight and a diet not enriched with vitamin D, bedridden pregnant women suffer from vitamin D deficiency and pregnancy complications lead often to birth of preterm neonates with the same deficiency. Mothers should increase the total amount of vitamin D intake (food and supplement).

Ultraviolet-B protection of ascorbate and tocopherol in plants related with their function on the stability on carotenoid and phenylpropanoid compounds

Ascorbate and tocopherol are important hydrophilic or lipophilic antioxidants in plants, while their crucial roles in the antioxidant defense system under ultraviolet B radiation were not well understood. The mutants of Arabidopsis thaliana deficient in ascorbate (vtc1 and vtc2) or tocopherol (vte1) were used to analyze their physiological, biochemical and metabolic change in responses to Ultraviolet B radiation. Results showed that loss of either ascorbate or tocopherol caused reduction in phenylpropanoid and flavonol glycosides compounds, as well as reduction in superoxide dismutase activity and total cellular antioxidant capacity. This ultimately led to higher oxidative stress as well as lower levels of photosynthetic pigments (carotenoid and chlorophyll) and CO2 assimilation rate in the vtc1, vtc2, and vte1 mutants than the wild type under UV-B radiation, besides unstable early light-induced protein (ELIP1) in those mutants. On the other hand, the loss of tocopherol in vte1 mutants was compensated by the increase of zeaxanthin and anthocyanin contents, which armed vte1 mutants with higher heat dissipation capacity in PS II and higher antioxidative capacity than vtc mutants. Consequently the tolerance to UV-B radiation were much higher in vte1 mutant than in vtc mutants, furthermore, PS II function and light harvesting protein (LHCb1) abundance were reduced only in ascorbate-deficient mutant relative to wild type. Our results suggested that the ascorbate and tocopherol provided not only direct protective function against UV-B radiation but also indirect effects by influencing other protective system, in particular by affecting the stability of various carotenoid and phenylpropanoid compounds.

Emphasizing the health benefits of vitamin D for those with neurodevelopmental disorders and intellectual disabilities

People with neurodevelopmental disorders and intellectual disabilities have much greater health care needs. Mainly staying indoors, such people generally have low 25-hydroxyvitamin D (25(OH)D) concentrations. The Vitamin D Task Force of the American Academy of Developmental Medicine and Dentistry (AADMD) reviewed the evidence of 25(OH)D concentrations that benefit the health of persons with developmental disabilities. Maintaining recommended optimal serum 25(OH)D concentrations year long will benefit skeletal development in infants, children, and adolescents, and benefit musculoskeletal health and neuromuscular coordination in adult patients, and decrease risk of falls. Maintaining optimal concentrations decreases risks and severities of autoimmune diseases, cardiovascular disease, many types of cancer, dementia, types 1 and 2 diabetes mellitus, and respiratory tract infections. Other benefits include improved dental and oral health and improved physical performance. The Task Force recommends that 25(OH)D concentrations for optimal health to be in the range of 75 to 125 nmol/L, which can be achieved using between 800 and 4000 IU/day vitamin D3 and sensible exposure to solar UVB radiation. The paper also discusses the potential risks of higher 25(OH)D concentrations, the evidence from and limitations of randomized controlled trials, and the recommendations by various groups and agencies.

Nitroso Diels-Alder (NDA) reaction as an efficient tool for the functionalization of diene-containing natural products

This review describes the use of nitroso Diels-Alder reactions for the functionalization of complex diene-containing natural products in order to generate libraries of compounds with potential biological activity. The application of this methodology to the structural modification of a series of natural products (thebaine, steroidal dienes, rapamycin, leucomycin, colchicine, isocolchicine and piperine) is discussed using relevant examples from the literature from 1973 onwards. The biological activity of the resulting compounds is also discussed. Additional comments are provided that evaluate the methodology as a useful tool in organic, bioorganic and medicinal chemistry.

Fortification of foods with vitamin D in India

Vitamin D deficiency is widely prevalent in India, despite abundant sunshine. Fortification of staple foods with vitamin D is a viable strategy to target an entire population. Vitamin D fortification programs implemented in the United States and Canada have improved the vitamin D status in these countries, but a significant proportion of the population is still vitamin D deficient. Before fortification programs are designed and implemented in India, it is necessary to study the efficacy of the American and Canadian vitamin D fortification programs and then improve upon them to suit the Indian scenario. This review explores potential strategies that could be used for the fortification of foods in the Indian context. These strategies have been proposed considering the diverse dietary practices necessitated by social, economic, cultural and religious practices and the diverse climatic conditions in India. Fortification of staple foods, such as chapati flour, maida, rice flour and rice, may be more viable strategies. Targeted fortification strategies to meet the special nutritional needs of children in India are discussed separately in a review entitled, "Fortification of foods with vitamin D in India: Strategies targeted at children".

The trials and tribulations of vitamin D: time for the 'sunshine' vitamin to come in out of the cold - or just more broken promises?

We are presently faced with the competing notions of modern life being a 'state of vitamin D depletion', implying a widespread need to supplement with vitamin D, or, the opposite view, which is that the present evidence can only support at best selective targeted vitamin D intervention. This is important as there is evidence that over the last 40-50 years there were downwards global trends in serum 25(OH)D concentrations, while individual consumption of vitamin D as supplements rose. For this reason and many others, a large population-based interventional study, the VITAL trial, was designed to try to establish the health value of vitamin D supplementation. VITAL is a huge primary prevention trial looking at the effects of vitamin D repletion in preventing cancer and cardiovascular disease in a fundamentally healthy population. This may seem an unusual approach given that what we mostly know about vitamin D is that is has some effects on the skeleton. This review looks to explore current knowledge about vitamin D in health and disease, and at how this is now undergoing significant reappraisal and revision. We will carefully critique the VITAL study design to see if it will allow for the construction of the detailed portfolio of clinical evidence so urgently needed to allow us better to understand role of vitamin D supplementation in health and disease.

Association of white matter hyperintensities with low serum 25-hydroxyvitamin D levels

BACKGROUND AND PURPOSE

Vitamin D deficiency is associated with cognitive impairment in the elderly and with increased white matter T2 hyperintensities in elderly debilitated patients. We investigated the relationship between serum vitamin D and brain MR findings in adult outpatients.

MATERIALS AND METHODS

Brain MR studies of 56 patients ages 30-69 years were selected when vitamin D level had been obtained within 90 days of the MRI. White matter T2 hyperintensities were characterized by size and location by two neuroradiologists. Manual volumetric analysis was assessed in patients more than 50 years of age.

RESULTS

The entire cohort showed a significant negative relationship between serum 25-hydroxyvitamin D and the number of confluent juxtacortical white matter T2 hyperintensities (P = .047). The cohort ages 50 years and older showed stronger correlation between confluent white matter T2 hyperintensities and serum 25-hydroxyvitamin D in the juxtacortical region; number (P = .015) and size of white matter T2 hyperintensities (P = .048). Atrophy was not significantly related to serum 25-hydroxyvitamin D by radiologist visual analysis or by the bicaudate ratio.

CONCLUSIONS

We found a significant relationship between vitamin D and white matter T2 hyperintensities in independent adult outpatients, especially over the age of 50 years.

Topical retinoids in skin ageing: a focused update with reference to sun-induced epidermal vitamin A deficiency

Vitamin A is an important constituent of the epidermis, where it plays a crucial role in epidermal turnover. A deficiency of epidermal vitamin A may be the consequence of nutritional vitamin A deficiency, exposure to sunlight or any UV source, oxidative stress or chronological ageing. As a consequence, any treatment aiming at increasing epidermal vitamin A would exert a protective effect against these deleterious conditions. Retinoids may counteract some deleterious actions of UV radiation by physical and biological mechanisms. Topical natural retinoic acid precursors such as retinaldehyde or retinol are less irritant than acidic retinoids and may prevent epidermal vitamin A deficiency due to nutritional deficiency, exposure to sunlight or any condition leading to free radical production. Retinoids may be combined with other compounds with complementary actions against ageing, nutritional deficiency and cancer, such as antioxidants, to potentiate their beneficial effects in the skin.

Synthesis, spectroscopic and theoretical studies of new quaternary N,N-dimethyl-3-phthalimidopropylammonium conjugates of sterols and bile acids

New quaternary 3-phthalimidopropylammonium conjugates of steroids were obtained by reaction of sterols (ergosterol, cholesterol, cholestanol) and bile acids (lithocholic, deoxycholic, cholic) with bromoacetic acid bromide to give sterol 3β-bromoacetates and bile acid 3α-bromoacetates, respectively. These intermediates were subjected to nuclephilic substitution with N,N-dimethyl-3-phthalimidopropylamine to give the final quaternary ammonium salts. The structures of products were confirmed by spectral (¹H-NMR, ¹³C-NMR, and FT-IR) analysis, mass spectrometry (ESI-MS, MALDI) as well as PM5 semiempirical methods and B3LYP ab initio methods. Estimation of the pharmacotherapeutic potential has been accomplished for synthesized compounds on the basis of Prediction of Activity Spectra for Substances (PASS).

Seasonal variation of 25-hydroxyvitamin D among non-Hispanic black and white pregnant women from three US pregnancy cohorts

BACKGROUND

Vitamin D deficiency during pregnancy has been associated with increased risk of complications and adverse perinatal outcomes. We evaluated seasonal variation of 25-hydroxyvitamin D [25(OH)D] among pregnant women, focusing on patterns and determinants of variation.

METHODS

Data came from three cohort studies in the US that included 2583 non-Hispanic Black and White women having prenatal 25(OH)D concentrations determined. Fourier time series and generalised linear models were used to estimate the magnitude of 25(OH)D seasonality. We modelled seasonal variability using a stationary cosinor model to estimate the phase shift, peak-trough difference, and annual mean of 25(OH)D.

RESULTS

We observed a peak for 25(OH)D in summer, a nadir in winter, and a phase of 8 months, which resulted from fluctuations in 25(OH)D3 rather than 25(OH)D2. After adjustment for covariates, the annual mean concentrations and estimated peak-trough difference of 25(OH)D among Black women were 19.8 ng/mL [95% confidence interval (CI) 18.9, 20.5] and 5.8 ng/mL [95% CI 4.7, 6.7], and for non-Hispanic White women were 33.0 ng/mL [95% CI 32.6, 33.4] and 7.4 ng/mL [95% CI 6.0, 8.9].

CONCLUSIONS

Non-Hispanic Black women had lower average 25(OH)D concentrations throughout the year and smaller seasonal variation levels than non-Hispanic White women. This study's confirmation of 25(OH)D seasonality over a calendar year has the potential to enhance public health interventions targeted to improve maternal and perinatal outcomes.

Benefits of ultraviolet-B irradiance and vitamin D in youth

A large and growing body of journal literature reports the health benefits of solar ultraviolet-B (UVB) irradiance and vitamin D. Most of the literature relates to the effects of vitamin D later in life, when chronic diseases are more likely to manifest and when the innate immune system is weaker, leading to increased rates of some infectious diseases. However, a significant body of literature exists on the health effects of solar UVB irradiance and serum 25-hydroxyvitamin D [25(OH)D] concentrations in youth. The goal of this paper is to review representative evidence of health benefits and risks of solar UVB irradiance and vitamin D for those aged from about 5 to 18 years. The topics discussed include physical development, athletic performance, infectious diseases, autoimmune diseases, metabolic syndrome, and cancer. Some of the effects of higher solar UVB irradiance and serum 25(OH)D concentrations are evident in youth, although some may become apparent later in life. This article is part of a Special Issue entitled 'Vitamin D Workshop'.

UV radiation and the skin

UV radiation (UV) is classified as a "complete carcinogen" because it is both a mutagen and a non-specific damaging agent and has properties of both a tumor initiator and a tumor promoter. In environmental abundance, UV is the most important modifiable risk factor for skin cancer and many other environmentally-influenced skin disorders. However, UV also benefits human health by mediating natural synthesis of vitamin D and endorphins in the skin, therefore UV has complex and mixed effects on human health. Nonetheless, excessive exposure to UV carries profound health risks, including atrophy, pigmentary changes, wrinkling and malignancy. UV is epidemiologically and molecularly linked to the three most common types of skin cancer, basal cell carcinoma, squamous cell carcinoma and malignant melanoma, which together affect more than a million Americans annually. Genetic factors also influence risk of UV-mediated skin disease. Polymorphisms of the melanocortin 1 receptor (MC1R) gene, in particular, correlate with fairness of skin, UV sensitivity, and enhanced cancer risk. We are interested in developing UV-protective approaches based on a detailed understanding of molecular events that occur after UV exposure, focusing particularly on epidermal melanization and the role of the MC1R in genome maintenance.