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Observational studies suggest that higher serum 25-hydroxyvitamin D concentration may be associated with lower risk of cataract. However, no randomized controlled trials (RCTs) have assessed the effect of vitamin D supplementation on the incidence of cataract. We aimed to assess whether vitamin D supplementation reduces the incidence of cataract surgery.We conducted an ancillary study of D-Health Trial, a randomized, double-masked, placebo-controlled trial of monthly vitamin D for the prevention of all-cause mortality conducted from 2014 to 2020 within the Australian general population.We invited 421,207 men and women aged 60-84 years to participate; including an additional 1,896 volunteers, 40,824 expressed interest. Those with hypercalcemia, hyperparathyroidism, kidney stones, osteomalacia or sarcoidosis, or who were taking500 international units (IU) supplemental vitamin D per day were excluded. 21,315 people were randomized. 1,390 participants did not fulfil the eligibility criteria for this analysis (linked data available, no cataract within first 6 months) leaving 19,925 included. The median follow-up was 5 years. .60,000 IU of vitamin DThe primary outcome for this analysis was the first surgical treatment for cataract, ascertained through linkage to universal health insurance records and hospital data.Among 19,925 participants eligible for the analysis of incident cataract (mean age 69.3 years, 46% women) 3,668 (18.4%) underwent cataract surgery during follow-up (n=1,841 (18.5%) of the vitamin D group and n=1,827 (18.3%) of the placebo group). The incidence of cataract surgery was similar between the two groups (incidence rate 41.6 and 41.1 per 1,000 person-years in the vitamin D and placebo groups, respectively; hazard ratio 1.02; 95% CI 0.95 to 1.09). In pre-specified subgroup analyses, the effect of vitamin D supplementation on the incidence of cataract surgery was not modified by age, sex, body mass index, predicted serum 25-hydroxyvitamin D concentration, or ambient ultraviolet radiation.Routinely supplementing older adults who live in an area with a low prevalence of vitamin D deficiency with high-dose vitamin D is unlikely to reduce the need for cataract surgery.

An increasing number of people develop more than 1 primary melanoma, yet to date, no population-based prospective cohort studies have reported on risk factors for developing first vs second primary melanomas.To compare the clinical characteristics of first and second melanomas and then to estimate the relative risks of developing 1 vs multiple melanomas associated with demographic, phenotypic, sun exposure, and genetic factors.This population-based prospective cohort study included men and women aged 40 to 69 years recruited in 2011 and followed up until December 2018 in Queensland, Australia. Data analysis was performed from February to July 2022.Self-reported information about demographic, phenotypic, and sun exposure measures captured using a survey completed at baseline, and polygenic risk score for melanoma.Incident first or second primary melanoma diagnosis, and histologic and clinical characteristics thereof. The Wei-Lin-Weissfeld model for recurrent events was used to estimate the association of each factor with the risks of first and second primary melanoma.A total of 38 845 patients (mean [SD] age at baseline, 56.1 [8.2] years; 17 775 men and 21 070 women) were included in the study. During a median follow-up period of 7.4 years, 1212 (3.1%) participants had a single primary melanoma diagnosis, and 245 (0.6%) had a second primary melanoma diagnosis. Second melanomas were more likely than first melanomas to be in situ; for invasive tumors, second melanomas were more likely to be thin (ie, ≤1 mm) than first melanomas. Having many moles at age 21 years (self-reported using visual scoring tool) was more strongly associated with second (hazard ratio [HR], 6.36; 95% CI, 3.77-10.75) than first primary melanoma (HR, 3.46; 95% CI, 2.72-4.40) (P value for difference between the HRs = .01). A high genetic predisposition (ie, polygenic risk score in tertile 3) was also more strongly associated with second (HR, 3.28; 95% CI, 2.06-5.23) than first melanoma (HR, 2.06; 95% CI, 1.71-2.49; P = .03). Second melanomas were more strongly associated with a history of multiple skin cancer excisions (HR, 2.63; 95% CI, 1.80-3.83) than first melanomas (HR, 1.86; 95% CI, 1.61-2.16; P = .05). For all other phenotypic characteristics and sun exposure measures, similarly elevated associations with first vs second melanomas were observed.Findings of this cohort study suggest that within the general population, the presence of many nevi and having a high genetic predisposition to melanoma were associated with the highest risks of developing second primary melanomas.

Observational studies suggest that 25-hydroxy vitamin D (25(OH)D) concentration is inversely associated with pain. However, findings from intervention trials are inconsistent. We assessed the effect of vitamin D supplementation on pain using data from a large, double-blind, population-based, placebo-controlled trial (the D-Health Trial). 21 315 participants (aged 60–84 years) were randomly assigned to a monthly dose of 60 000 IU vitamin D3 or matching placebo. Pain was measured using the six-item Pain Impact Questionnaire (PIQ-6), administered 1, 2 and 5 years after enrolment. We used regression models (linear for continuous PIQ-6 score and log-binomial for binary categorisations of the score, namely ‘some or more pain impact’ and ‘presence of any bodily pain’) to estimate the effect of vitamin D on pain. We included 20 423 participants who completed ≥1 PIQ-6. In blood samples collected from 3943 randomly selected participants (∼800 per year), the mean (sd) 25(OH)D concentrations were 77 (sd 25) and 115 (sd 30) nmol/l in the placebo and vitamin D groups, respectively. Most (76 %) participants were predicted to have 25(OH)D concentration >50 nmol/l at baseline. The mean PIQ-6 was similar in all surveys (∼50·4). The adjusted mean difference in PIQ-6 score (vitamin D cf placebo) was 0·02 (95 % CI (−0·20, 0·25)). The proportion of participants with some or more pain impact and with the presence of bodily pain was also similar between groups (both prevalence ratios 1·01, 95 % CI (0·99, 1·03)). In conclusion, supplementation with 60 000 IU of vitamin D3/month had negligible effect on bodily pain.

PURPOSE Thyroid autoimmunity has been associated with differentiated thyroid cancer although multiple potential biases might have influenced the results of previous studies. METHODS We conducted a case-control study nested within the cohort of US active-duty personnel 1996-2014 to assess the association between thyroid autoimmunity, defined by serology, and thyroid cancer diagnosis. The primary exposure was thyroid peroxidase (TPO) antibody status 7-10 years before the thyroid cancer index date. We also assessed whether diagnosis of thyroid autoimmunity mediated any associations identified and if thyroid cancer features differed by autoimmunity status. RESULTS Among 451 incident cases of papillary thyroid cancer and matched controls (median age 36 years, 61.4% men), TPO antibody positivity ( v negative) 7-10 years prediagnosis was associated with thyroid cancer (odds ratio [OR] 1.90 [95% CI, 1.33 to 2.70]). Exploratory analyses suggested an increasing risk of thyroid cancer with higher TPO antibody titer (TPO antibody 550-1,399 IU/mL: OR 2.95 [95% CI, 1.37 to 6.36]; and ≥ 1,400 IU/mL: OR 3.91 [95% CI, 1.66 to 9.24]). Positive TPO antibody status remained associated with thyroid cancer after those with diagnosed autoimmunity were excluded, and the association was not mediated by diagnosis of thyroid autoimmunity. Among the cases with diagnosed autoimmunity, 58% thyroid cancers were ≤ 10 mm diameter. CONCLUSION Longstanding prior thyroid autoimmunity up to 10 years before thyroid cancer diagnosis was associated with papillary thyroid cancer risk. The results could not be fully explained by diagnosis of thyroid autoimmunity although when autoimmunity had been identified, thyroid cancers were diagnosed at a very early stage.

Supplemental figures 1 and 2. Supplemental tables 1-7.

To evaluate the effect of vitamin D(3) supplementation on cancer mortality in the general population and on prognosis in cancer patients, a systematic review and meta-analysis of randomised, placebo-controlled trials (RCTs) and individual patient data (IPD) was conducted. Overall, 14 RCTs with a total of 104,727 participants (2015 cancer deaths) were identified and 7 RCTs, including 90 % of all study participants (n = 94,068), could be included in the IPD meta-analyses. The main meta-analysis of the 14 RCTs yielded a statistically non-significant reduction in cancer mortality by 6 % (risk ratio (RR) [95%-confidence interval (95%CI)]: 0.94 [0.86–1.02]). Subgroup analyses revealed a 12 % lower cancer mortality in the vitamin D(3) group compared with the placebo group in 10 trials with a daily dosing regimen (RR [95%CI]: 0.88 [0.78–0.98]), whereas no mortality reduction was seen in 4 trials using a bolus regimen (RR [95%CI]: 1.07 [0.91–1.24]; p-value for interaction: 0.042). The IPD meta-analysis (RR [95%CI]: 0.93 [0.84; 1.02]) confirmed the finding of all trials. The IPD were used to test effect modification by age, sex, body mass index, ethnicity, baseline serum 25-hydroxyvitamin D concentration, adherence and cancer-related factors but no statistically significant findings were obtained in meta-analyses of all trials. When restricted to trials with daily dosing in a post-hoc analysis, adults aged ≥ 70 years (RR [95%CI]: 0.83 [0.77; 0.98]) and subjects with vitamin D(3) therapy initiation before cancer diagnosis (RR [95%CI]: 0.87 [0.69; 0.99]) appeared to benefit most from daily vitamin D(3) supplementation. Measurements of baseline 25-hydroxyvitamin D levels and inclusion of other than non-Hispanic White adults were too sparse in the trials to draw conclusions. Results for all-cause and cancer-specific survival of participants with cancer were comparable to those obtained in the general population for cancer mortality. In conclusion, vitamin D(3) did not reduce cancer mortality in the main meta-analysis of all RCTs because the observed risk reduction by 6 % was not statistically significant. However, a subgroup analysis revealed that vitamin D(3) administered daily, in contrast to bolus supplementation, reduced cancer mortality by 12 %.

PDF file - 45K, Associations between cumulative HPV load and SCC, stratified by skin type and time since transplantation (for OTR). In each case the reference category is HPV negative combined with the lowest load tertile.

Background: Beta-human papillomavirus (betaPV) may play a role in the development of cutaneous squamous cell carcinoma (SCC). However betaPV is highly prevalent, and it may only be people with a higher viral load who have increased risk of SCCs. We therefore examined the association between betaPV load and SCCs.Methods: We recruited 448 immunocompetent cases with SCCs and 464 controls from Italy and Australia and 497 immunosuppressed organ transplant recipients (OTR; 179 cases and 318 controls) from Europe. We used reverse hybridization to genotype 25 betaPV types in eyebrow hair follicles and determined the viral load for eight selected types using quantitative PCR. We used logistic regression to assess associations between type-specific and cumulative viral load and SCCs.Results: Australian and OTR participants in the highest cumulative load tertile were at significantly higher risk of SCCs than those in the lowest tertile. Those with more than four betaPV types in the high load tertile were at approximately three-fold increased risk of SCCs. In Australia, HPV23 and 36 loads were significantly associated with SCCs, with borderline associations for HPV5 and 38. In OTR, HPV8 and 38 loads were significantly associated and HPV20 and 36 were borderline. We found little evidence for an association between load and SCCs in Italy.Conclusions: High viral load may be associated with risk of cutaneous SCCs, with total load seemingly more important than the load of any specific type.Impact: Our findings lend weight to the hypothesis that HPV plays a role in skin carcinogenesis. Cancer Epidemiol Biomarkers Prev; 22(4); 719–27. ©2013 AACR.

PDF - 98K, Quality assessment checklist.

Epidemiologic research has shown that cutaneous markers of photo-damage are associated with risk of basal cell carcinoma (BCC). However, there has been no previous attempt to calculate pooled risk estimates. We conducted a systematic review and meta-analysis after extracting relevant studies published up to January 2013 from five electronic databases. Eligible studies were those that permitted quantitative assessment of the association between histologically confirmed BCC and actinic keratoses, solar elastosis, solar lentigines, or telangiectasia. Seven eligible studies were identified and summary odds ratios (ORs) were calculated using both random and quality effects models. Having more than ten actinic keratoses was most strongly associated with BCC, conferring up to a fivefold increase in risk (OR: 4.97; 95% CI: 3.26–7.58). Other factors, including solar elastosis, solar lentigines, and telangiectasia had weaker but positive associations with BCC with ORs around 1.5. Markers of chronic photo-damage are positively associated with BCC. The presence of actinic keratoses was the most strongly associated with BCC of the markers examined. This work highlights the relatively modest association between markers of chronic ultraviolet exposure and BCC. Cancer Epidemiol Biomarkers Prev; 22(9); 1483–9. ©2013 AACR.

Registry-based epidemiologic studies suggest associations between chronic inflammatory intestinal diseases and pancreatic ductal adenocarcinoma (PDAC). As genetic susceptibility contributes to a large proportion of chronic inflammatory intestinal diseases, we hypothesize that the genomic regions surrounding established genome-wide associated variants for these chronic inflammatory diseases are associated with PDAC. We examined the association between PDAC and genomic regions (±500 kb) surrounding established common susceptibility variants for ulcerative colitis, Crohn's disease, inflammatory bowel disease, celiac disease, chronic pancreatitis, and primary sclerosing cholangitis. We analyzed summary statistics from genome-wide association studies data for 8,384 cases and 11,955 controls of European descent from two large consortium studies using the summary data-based adaptive rank truncated product method to examine the overall association of combined genomic regions for each inflammatory disease group. Combined genomic susceptibility regions for ulcerative colitis, Crohn disease, inflammatory bowel disease, and chronic pancreatitis were associated with PDAC at P values < 0.05 (0.0040, 0.0057, 0.011, and 3.4 × 10−6, respectively). After excluding the 20 PDAC susceptibility regions (±500 kb) previously identified by GWAS, the genomic regions for ulcerative colitis, Crohn disease, and inflammatory bowel disease remained associated with PDAC (P = 0.0029, 0.0057, and 0.0098, respectively). Genomic regions for celiac disease (P = 0.22) and primary sclerosing cholangitis (P = 0.078) were not associated with PDAC. Our results support the hypothesis that genomic regions surrounding variants associated with inflammatory intestinal diseases, particularly, ulcerative colitis, Crohn disease, inflammatory bowel disease, and chronic pancreatitis are associated with PDAC.Significance:The joint effects of common variants in genomic regions containing susceptibility loci for inflammatory bowel disease and chronic pancreatitis are associated with PDAC and may provide insights to understanding pancreatic cancer etiology.

Germline variation and smoking are independently associated with pancreatic ductal adenocarcinoma (PDAC). We conducted genome-wide smoking interaction analysis of PDAC using genotype data from four previous genome-wide association studies in individuals of European ancestry (7,937 cases and 11,774 controls). Examination of expression quantitative trait loci data from the Genotype-Tissue Expression Project followed by colocalization analysis was conducted to determine whether there was support for common SNP(s) underlying the observed associations. Statistical tests were two sided and P < 5 × 10–8 was considered statistically significant. Genome-wide significant evidence of qualitative interaction was identified on chr2q21.3 in intron 5 of the transmembrane protein 163 (TMEM163) and upstream of the cyclin T2 (CCNT2). The most significant SNP using the Empirical Bayes method, in this region that included 45 significantly associated SNPs, was rs1818613 [per allele OR in never smokers 0.87, 95% confidence interval (CI), 0.82–0.93; former smokers 1.00, 95% CI, 0.91–1.07; current smokers 1.25, 95% CI 1.12–1.40, Pinteraction = 3.08 × 10–9). Examination of the Genotype-Tissue Expression Project data demonstrated an expression quantitative trait locus in this region for TMEM163 and CCNT2 in several tissue types. Colocalization analysis supported a shared SNP, rs842357, in high linkage disequilibrium with rs1818613 (r2 = 0. 94) driving both the observed interaction and the expression quantitative trait loci signals. Future studies are needed to confirm and understand the differential biologic mechanisms by smoking status that contribute to our PDAC findings.Significance:This large genome-wide interaction study identifies a susceptibility locus on 2q21.3 that significantly modified PDAC risk by smoking status, providing insight into smoking-associated PDAC, with implications for prevention.

Supplemental Table 8. Enrichment in regulatory regions for rs842357 and related SNPs

Supplementary Figure 1 from Persistence of Betapapillomavirus Infections as a Risk Factor for Actinic Keratoses, Precursor to Cutaneous Squamous Cell Carcinoma

Human papillomaviruses from the β genus (βPV) are a possible cause of cutaneous squamous cell carcinoma (SCC). We assessed the extent to which βPV infections persisted long-term in a subtropical Australian community and whether βPV persistence is positively associated with actinic keratoses, precursor for SCC. Eyebrow hairs were collected from 171 participants of the community-based Nambour Skin Cancer Study in 1996 and 2003. Hair samples were tested for the presence of DNA from 25 different βPV types and assessed in relation to actinic keratosis presence in 2007. In 1996, a total of 413 βPV infections were found in 73% of participants, increasing to 490 infections among 85% in 2003. Of the total βPV infections detected, 211 (30%) were found to persist. Age was significantly associated with βPV persistence: those ages >60 years had 1.5-fold (95% confidence interval, 1.1-1.9) increased risk of type-specific viral persistence than those ages

Supplementary Figure Legend from Persistence of Betapapillomavirus Infections as a Risk Factor for Actinic Keratoses, Precursor to Cutaneous Squamous Cell Carcinoma

Background Falls cause considerable morbidity and mortality in older people. It is unclear how vitamin D supplementation affects falls risk, particularly when taken at high doses. We sought to determine whether monthly high‐dose vitamin D supplementation reduces risk and incidence of falls. Methods We used data from the randomized, double‐blind, placebo‐controlled D‐Health Trial conducted in Australia. Between February 2014 and May 2015, 21 315 participants aged 60–84 years were randomized (1:1) to monthly doses of either 60 000 IU of colecalciferol or placebo for a maximum of 5 years. People who reported a history of osteomalacia, sarcoidosis, hyperparathyroidism, hypercalcaemia or kidney stones or who were taking >500 IU/day supplementary vitamin D were ineligible. Each year, we collected blood samples from ~450 randomly sampled participants from each trial arm and measured 25‐hydroxyvitamin D [25(OH)D]. Falls, a prespecified tertiary outcome, were ascertained using annual surveys and, for a subset of participants, 3‐month falls diaries. The primary outcome for this analysis was any fall in the month before completing an annual survey. As part of our process to maintain blinding, we used random samples of participants (surveys, n = 16 000; diaries, n = 2400), with equal numbers per group. Participants with no outcome data were excluded. Following an intention‐to‐treat approach, we analysed outcomes using logistic, ordinal and negative binomial regression. Registration: Australian New Zealand Clinical Trials Registry (ACTRN12613000743763); registered 4 July 2013. Results Mean treatment duration was 4.3 years (standard deviation [SD] = 1.4 years). Mean serum 25(OH)D concentrations during the trial were 114.8 (SD 30.3) nmol/L and 77.5 (SD 25.2) nmol/L in the vitamin D and placebo groups, respectively. Survey and diary analytic sets included 15 416 and 2200 participants, respectively; approximately half were randomized to vitamin D (surveys: 50.1%; diaries: 50.4%). Vitamin D had no effect on falling in the past month (odds ratio [OR] 1.02, 95% confidence interval [CI] 0.95–1.10). There was an interaction with body mass index (BMI) (P‐interaction = 0.001); vitamin D increased risk in participants with BMI

OBJECTIVE: Smoking has been associated with a reduced risk of thyroid cancer, but whether the association varies between higher- and lower-risk cancers remains unclear. We aimed to assess the association between smoking and risk of thyroid cancer overall as well as by tumour BRAF mutational status as a marker of potentially higher-risk cancer. DESIGN AND PATIENTS: We recruited 1013 people diagnosed with thyroid cancer and 1057 population controls frequency-matched on age and sex. METHODS: Multivariable logistic regression was used to assess the association overall and in analyses stratified by tumour characteristics. We used sensitivity analysis to assess the potential for selection bias. RESULTS: We found little evidence of an association with current smoking (odds ratio [OR] = 0.93; 95% confidence interval [CI]: 0.69-1.26; current vs. never smoking), but a higher number of pack-years of smoking was associated with a lower risk of thyroid cancer (OR = 0.75; 95% CI: 0.57-0.99; ≥20 pack-years vs. never). However, after correcting for potential selection bias, we observed a statistically significant inverse association between current smoking and risk of thyroid cancer (bias-corrected OR = 0.65; 95% CI: 0.51-0.83). Those with BRAF-positive cancers were less likely to be current smokers than those with BRAF-negative cancers (prevalence ratio: 0.79; 95% CI: 0.62-0.99). CONCLUSION: We found smoking was inversely related to thyroid cancer risk and, in particular, current smoking was associated with a reduced risk of potentially more aggressive BRAF-positive than the likely more indolent BRAF-negative papillary thyroid cancers.

ObjectiveGastro-oesophageal reflux disease (GERD) has heterogeneous aetiology primarily attributable to its symptom-based definitions. GERD genome-wide association studies (GWASs) have shown strong genetic overlaps with established risk factors such as obesity and depression. We hypothesised that the shared genetic architecture between GERD and these risk factors can be leveraged to (1) identify new GERD and Barrett’s oesophagus (BE) risk loci and (2) explore potentially heterogeneous pathways leading to GERD and oesophageal complications.DesignWe applied multitrait GWAS models combining GERD (78 707 cases; 288 734 controls) and genetically correlated traits including education attainment, depression and body mass index. We also used multitrait analysis to identify BE risk loci. Top hits were replicated in 23andMe (462 753 GERD cases, 24 099 BE cases, 1 484 025 controls). We additionally dissected the GERD loci into obesity-driven and depression-driven subgroups. These subgroups were investigated to determine how they relate to tissue-specific gene expression and to risk of serious oesophageal disease (BE and/or oesophageal adenocarcinoma, EA).ResultsWe identified 88 loci associated with GERD, with 59 replicating in 23andMe after multiple testing corrections. Our BE analysis identified seven novel loci. Additionally we showed that only the obesity-driven GERD loci (but not the depression-driven loci) were associated with genes enriched in oesophageal tissues and successfully predicted BE/EA.ConclusionOur multitrait model identified many novel risk loci for GERD and BE. We present strong evidence for a genetic underpinning of disease heterogeneity in GERD and show that GERD loci associated with depressive symptoms are not strong predictors of BE/EA relative to obesity-driven GERD loci.

To investigate whether vitamin D supplementation reduces depressive symptoms and incidence of antidepressant use.We used data from the D-Health Trial (N = 21,315), a randomized double-blind placebo-controlled trial of monthly vitamin DAnalyses of PHQ-9 scores included 20,487 participants (mean age 69·3 years, 46% women); the mean difference (MD) in PHQ-9 score (vitamin D vs. placebo) was 0·02 (95% CI -0·06, 0·11). There was negligible difference in the prevalence of clinically relevant depression (PHQ-9 score ≥10) (odds ratio 0·99; 95% CI 0·90, 1·08). We included 16,670 participants in the analyses of incident antidepressant use (mean age 69·4 years, 43% women). Incidence of antidepressant use was similar between the groups (hazard ratio [HR] 1·04; 95% CI 0·96, 1·12). In subgroup analyses, vitamin D improved PHQ-9 scores in those taking antidepressants at baseline (MD -0·25; 95% CI -0·49, -0·01; p-interaction = 0·02). It decreased risk of antidepressant use in participants with predicted 25(OH)D concentration50 nmol/L (HR 0·88; 95% CI 0·75, 1·02; p-interaction = 0·01) and increased risk in those with predicted 25(OH)D ≥ 50 nmol/L (HR 1·10; 95% CI 1·01, 1·20).Monthly supplementation with high-dose vitamin DThe trial is registered on the Australian New Zealand Clinical Trials Registry: ACTRN12613000743763. https://www.anzctr.org.au/.

Information about the prevalence of photodermatoses is lacking, despite their substantial impact on life quality. Our objective was to systematically review the literature to establish what is known regarding prevalence and incidence of photodermatoses. We searched Medline, CINAHL and Embase from inception to 2021 to identify original population-based studies in English literature reporting the prevalence and/or incidence of photodermatoses. Information was extracted according to geographical location and risk of bias was assessed using a 10-point risk of bias tool for prevalence studies. Primary outcome was the population prevalence of photodermatoses. Prevalence data for polymorphic light eruption (PLE) were used to calculate the global pooled prevalence of PLE. Twenty-six studies were included; 15 reported prevalence of photodermatoses based on samples of the general population and 11 on prevalence and/or incidence from national and international registry data. The general population studies involved PLE (nine studies), unspecified photosensitivity (2), actinic prurigo (2), juvenile spring eruption (1), chronic actinic dermatitis (1) and variegate porphyria (1), while registry studies reported on cutaneous porphyrias and genophotodermatoses (nine and two studies, respectively). Worldwide the prevalence of PLE between countries ranged from 0.65% (China) to 21.4% (Ireland). The pooled estimated prevalence of PLE was 10% (95% CI 6%–15%) among the general population (n = 19,287), and PLE prevalence increased with distance from the equator (r = 0.78, p < 0.001). While several photodermatoses are rare, photosensitivity can be prevalent at wide-ranging world locations, including Egypt where photosensitivity was found in 4% of children and 10% of adults. This study showed that PLE is highly prevalent in many populations and that its prevalence shows a highly significant correlation with increasing northerly or southerly latitude. Available population-based studies for photodermatoses suggest they can be prevalent at a range of world locations; more attention is required to this area. © 2022 The Authors. Journal of the European Academy of Dermatology and Venereology published by John Wiley & Sons Ltd on behalf of European Academy of Dermatology and Venereology.

Summary Background Vitamin D may play a role in prevention of keratinocyte cancer (KC), but observational studies examining the association between serum 25-hydroxy vitamin D concentration and KC are largely uninformative because sun exposure causes both KC and vitamin D production. There is scant evidence from clinical trials of supplementary vitamin D. Objectives To examine the effect of vitamin D supplementation on the risk of developing KC. Methods We used data from the D-Health Trial, a randomized placebo-controlled trial of vitamin D supplementation (60 000 international units monthly for 5 years) among Australians aged ≥60 years. KC outcomes were captured through linkage to a national administrative dataset for those who consented (N = 20 334; 95%). We used negative binomial regression to analyse the incidence of KC excisions and the incidence of actinic lesions treated using cryotherapy or serial curettage, and flexible parametric survival models for analysis of time to first KC excision. Results Randomization to vitamin D supplementation did not reduce the incidence of KC lesions treated by excision [incidence rate ratio (IRR) 1·04; 95% confidence interval (CI) 0·98–1·11], the incidence of actinic lesions treated using other methods (IRR 1·01; 95% CI 0·95–1·08) or time to first histologically confirmed KC excision (hazard ratio 1·02; 95% CI 0·97–1·08). However, in subgroup analysis vitamin D increased the incidence of KC excisions in adults aged ≥ 70 years (IRR 1·13, 95% CI 1·04–1·23; P-value for interaction = 0·01). Conclusions Vitamin D supplementation did not reduce the incidence of KC or other actinic lesions. What is already known about this topic? Laboratory studies have suggested possible protective effects of vitamin D on skin cancer.Observational studies investigating the association between vitamin D and risk of keratinocyte cancer are largely uninformative as ultraviolet radiation both causes skin cancer and is the primary source of vitamin D.The evidence from randomized controlled trials of vitamin D is limited and inconclusive. What does this study add? This population-based, randomized controlled trial suggests that supplementing older adults with a high monthly dose of vitamin D for 5 years does not affect the incidence of keratinocyte cancer.