Shining light on the vitamin D: Cancer connection IARC report

Knowledge and practice of mothers towards sunshine exposure of their children in Ethiopia: a systematic review and meta-analysis

BACKGROUND

Early morning sunlight exposure for infants is a good practice to prevent rickets and alleviate the problem of vitamin D deficiency. Rickets is a major public health problem in many countries especially in developing country including Ethiopia. As mothers are frontline person for their children who should know and practice about sunlight exposure, this systematic review and meta-analysis aimed to assess the pooled level of knowledge and practice towards sunlight exposure of their children among mothers in Ethiopia.

METHODS

PubMed, Google Scholar, Excerpta Medica database (EMBASE), Cochrane Library, Web of Science, and African Journal of Online (AJOL) were searched. The data were extracted using Microsoft Excel and analyzed using STATA version 14. Publication bias was checked by funnel plot and more objectively through Egger's regression test, with P < 0.05 considered to indicate potential publication bias. The heterogeneity of studies was checked using I² statistics. Pooled analysis was conducted using a weighted inverse variance random-effects model. Subgroup analysis was done related to geographic region and time. A leave-one-out sensitivity analysis was also employed.

RESULT

A total of 8 studies with 2974 study participants for knowledge, nine studies with 3475 study participants for practice were used to estimate the pooled level of good knowledge and good practice of sunshine exposure among Ethiopian mothers. The overall estimated good level of knowledge and good practice towards sunshine exposure of their children among mothers was found to be 56.08% ((95% CI: 46.26 - 65.89%; I2 = 96.8%) and 55.632% (95%CI: 44.091 - 67.174%; I2 = 98.2%). Regional subgroup analysis showed that the pooled level of good practice in Amhara and Sidama regions found to be 54.41 and 58.32% respectively.

CONCLUSION

Study findings showed mothers knowledge and practice towards sunshine exposure of children was quite low in Ethiopia. This study therefore recommends that interventions are needed to increase knowledge and practice of sunlight exposure. This study provides much needed significant evidence for making health-policy recommendations for this vulnerable population group.

Side-Effects of Convulsive Seizures and Anti-Seizure Therapy on Bone in a Rat Model of Epilepsy

The severe sole effects of seizures on the cortical part of bone were reported in our previous study. However, the side effects of anti-epileptic drug therapy on bones has not been differentiated from the effects of the convulsive seizures, yet. This study provides the first report on differentiation of the effects of seizures and carbamazepine (a widely used antiepileptic drug) therapy on bones; 50 mg/kg/day drug was given to genetically induced absence epileptic rats for five weeks. Distinct bone regions including cortical, trabecular, and growth plate in each of tibia, femur, and spine tissues were studied using Fourier transform infrared (FT-IR) imaging and Vickers microhardness test. Blood levels of vitamin D and bone turnover biomarkers were also measured. According to the FT-IR imaging results, both seizure and carbamazepine-treated groups, more dominantly the drug-treated group, had lower mineral content with altered collagen crosslinks and higher crystallinity, implying reduced bone strength. Lower microhardness values also supported lower mechanical strength in bones. The most affected bone tissue and region from seizures and treatment was found as the spine and cortical, respectively. While there was a reduction in vitamin D and calcium levels in both seizure and carbamazepin-treated groups, significantly elevated PTH and bone turnover biomarkers were only seen in the drug-treated group.

Maternal vitamin D sufficiency and reduced placental gene expression in angiogenic biomarkers related to comorbidities of pregnancy

INTRODUCTION

Maternal circulating 25-hydroxyvitamin D [25(OH)D] has been shown to optimize production of 1,25-dihydroxyvitamin D [1,25(OH)₂D] during pregnancy at approximately 100nmoles/L, which has pronounced effects on fetal health outcomes. Additionally, associations are noted between low maternal 25(OH)D concentrations and vascular pregnancy complications, such as preeclampsia. To further elucidate the effects of vitamin D activity in pregnancy, we investigated the role of maternal 25(OH)D, the nutritional indicator of vitamin D status, in relation to placental maintenance and, specifically, expression of placental gene targets related to angiogenesis and vitamin D metabolism.

METHODS

A focused analysis of placental mRNA expression related to angiogenesis, pregnancy maintenance, and vitamin D metabolism was conducted in placentas from 43 subjects enrolled in a randomized controlled trial supplementing 400IU or 4400IU of vitamin D₃ per day during pregnancy. Placental mRNA was isolated from biopsies within one hour of delivery, followed by quantitative PCR. We classified pregnant women with circulating concentrations of <100nmoles/L as deficient and those with ≥100nmoles/L as sufficient. The value of each gene's change in the PCR cycle threshold (ΔCT), which is a relative measure of target concentration, was compared with maternal 25(OH)D concentrations <100nmoles/L and ≥100nmoles/L based on a two-sample Wilcoxon test.

RESULTS

Soluble FMS-like tyrosine kinase 1 (sFlt-1) and vascular endothelial growth factor (VEGF) gene expression was significantly downregulated in the maternal subgroup with circulating 25(OH)D ≥100ng/mL compared to the subgroup <100ng/mL.

DISCUSSION

Here, we report a significant association between maternal vitamin D status and the expression of sFlt-1 and VEGF at the mRNA level. Achieving maternal circulating 25(OH)D ≥100nmoles/L suggests the impact of maternal vitamin D₃ supplementation on gene transcription in the placenta, thereby potentially decreasing antiangiogenic factors that may contribute to vascular pregnancy complications.

Shedding new light on the role of the sunshine vitamin D for skin health: the lncRNA-skin cancer connection

Throughout evolution, vertebrates including humans have depended on the sunshine vitamin D for their calcified skeletons. As our hunter gatherer forefathers ventured from the equator, their skin tone became much lighter in order to permit an adequate amount of ultraviolet B radiation to enter the skin to produce the vitally important vitamin D. Although sensible sun exposure does not significantly increase risk of skin cancer, it has remained a mystery as to why. Jiang and Bikle in their viewpoint provide a novel insight as to how Mother Nature was able to balance the need for receiving adequate sun exposure to produce vitamin D while limiting damage caused by the DNA absorbing the ultraviolet B radiation. Long non-coding RNAs which are plentiful in cells have a dual personality. Some enhance malignancy, while others act as tumor suppressors. Jiang and Bikle provide compelling evidence that these long non-coding RNAs in skin cells are responsive to 1,25-dihydroxyvitamin D3 by decreasing their carcinogenic activity while enhancing their tumor suppression function presumably as a strategy for reducing ultraviolet-induced non-melanoma skin cancer. Mother Nature got it right. Sensible sun exposure is important for maintaining an adequate vitamin D status. Once formed in the skin, vitamin D can exit into the circulation to carry out its physiologic functions on calcium and bone metabolism. Some vitamin D however remains in the skin and is activated to interact with its vitamin D receptor to control cell proliferation using a variety of strategies including interacting with long non-coding RNAs to reduce risk of photocarcinogenesis.

Oral cholecalciferol versus ultraviolet radiation B: effect on vitamin D metabolites in patients with chronic pancreatitis and fat malabsorption - a randomized clinical trial

BACKGROUND

Patients with chronic pancreatitis (CP) often develop fat malabsorption and are susceptible to hypovitaminosis D.

AIM

We wanted to evaluate the intestinal uptake of cholecalciferol in patients with CP and fat malabsorption.

METHODS

We did a prospective placebo-controlled study including patients with verified CP and fat malabsorption. They were randomized to 10 weeks of (A) ultraviolet radiation B (UVB) 6 min weekly in a commercial tanning bed, (B) vitamin D supplement 1,520 IU/daily, or (C) placebo. The vitamin D metabolites 25-hydroxyvitamin D (25OHD) and 1,25-dihydroxyvitamin D (calcitriol) were quantified at the start and end of the study.

RESULTS

In total 30 patients were randomized and 27 completed the study. Compliance to tablets and tanning sessions was >80%. The changes in 25OHD levels in group B (32.3 nmol/l; 95% CI 15-50) were significantly greater than changes in group A (p < 0.001) and group C (p < 0.001). Changes in group A (1.1 nmol/l) did not differ from the placebo group (p = 0.9). Changes in calcitriol levels were identical between groups.

CONCLUSIONS

Daily vitamin D supplements increased 25OHD in patients with CP compared to placebo whereas weekly tanning bed sessions did not.

Sunlight robbery: a critique of public health policy on vitamin D in the UK

The British Isles have a very cloudy climate and as a result receive fewer hours of clear sunlight than most other industrial regions. The majority of people in these islands have low blood levels of vitamin D [25(OH)D] all year round. Few food products are fortified with vitamin D in the UK and the government does not recommend any vitamin D supplement for most adults in the UK. Diseases associated with vitamin D insufficiency such as cancer, heart disease, diabetes (types 1 and 2) and multiple sclerosis are more frequent in the UK, and particularly in Scotland, than in many other European countries and some, such as multiple sclerosis and diabetes (types 1 and 2), are increasing in incidence. Present knowledge suggests that the risk of some chronic diseases could be reduced if vitamin D intake or sun exposure of the population were increased. Yet policy and public health recommendations of the UK government and its agencies (e.g. the Health Protection Agency, the Food Standards Agency) and of Cancer Research UK have failed to take full account of established and putative benefits of vitamin D and/or sunshine. The epidemic of chronic disease in the UK, which is associated with and caused at least in part by vitamin D insufficiency, has not been adequately recognized by these agencies, and too often measures taken by them have been misguided, inappropriate or ineffective.

Cutaneous vitamin D synthesis versus skin cancer development: The Janus faces of solar UV-radiation

In scientific and public communities, there is an ongoing discussion how to balance between positive and negative effects of solar UV-exposure. On the one hand, solar UV-radiation represents the most important environmental risk factor for the development of non-melanoma skin cancer. Consequently, UV protection is an important measure to prevent these malignancies, especially in risk groups. Otherwise, approximately 90% of all vitamin D needed by the human body has to be formed in the skin through the action of UV-radiation. This dilemma represents a serious problem, for an association of vitamin D-deficiency and multiple independent diseases including various types of cancer, bone diseases, autoimmune diseases, infectious diseases, cardiovascular diseases and hypertension has now been reported in a large number of investigative and epidemiologic studies. As a consequence, it has been assumed that for the general population in the US, Europe and other countries, the net effects of solar UV B-radiation on human health are beneficial at or near current levels. We and others have shown that strict sun protection causes vitamin D-deficiency/insufficiency and that detection and treatment of vitamin D-deficiency in sun deprived risk groups is of high importance. Although further work is necessary to define an adequate vitamin D-status and adequate guidelines for solar and artificial UV-exposure, it is at present mandatory that public health campaigns and sun protection recommendations to prevent skin cancer consider these facts. In this review, we analyze the present literature to help developing well-balanced recommendations on sun protection that ensure an adequate vitamin D-status. These recommendations will hopefully protect us against adverse effects of UV protection without significantly increasing the risk to develop UV-induced skin cancer.