A critical review of Vitamin D and Cancer: A report of the IARC Working Group

Potential role of serum vitamin D as a risk factor in pediatric acute lymphoblastic leukemia

Vitamin D deficiency/insufficiency (VDD, VDI) is common in children yet limited experience exists on the association of VDD and hematologic malignancies amongst this population. Therefore, this study aimed to compare serum vitamin D levels in children with acute lymphoblastic leukemia (ALL) and controls. Moreover, vitamin D levels is compared in subjects with and without relapse and evaluated as a prognostic factor for relapse-free survival (RFS). Children with newly diagnosed ALL were recruited as case group. Data on demographic variables as well as the dietary habits were collected by interview. In addition, serum 25(OH)D3 was measured. The case group was followed up for 36 months to assess RFS. Overall, 358 subjects were included in the study (n = 169 cases, n = 189 controls). The mean levels of 25(OH)D3 were 28.05 ± 18.87 and 28.76 ± 12.99 in cases and controls, respectively (p = .68). VDD was found in 15.4% (n = 26) and 4.2% (n = 8) of the case and control groups, respectively (p < .001). Relapse was seen in 18.34% of patients and vitamin D levels of 20 ng/mL or above were associated with longer RFS (p = .044 by log-rank test). In this study, VDD and VDI amongst children with ALL were significantly higher than controls. In addition, lower levels of Vitamin D were associated with increased risk of relapse.

Lower vitamin D levels and VDR variants are risk factors for breast cancer: an updated meta-analysis

Inadequate vitamin D levels and vitamin D variants have been shown to be associated with breast cancer (BC), however the results are inconsistent. To reach a definitive conclusion the present meta-analysis was conducted. When compared to healthy controls, BC patients had reduced vitamin D levels (standard difference in means = -0.564, p = 0.003). The meta-analysis revealed that the FokI mutation was linked with an increased BC susceptibility (CC vs. TT: OR = 1.107, p = 0.001, CC vs. TC + TT: OR = 1.114, p = 0.020). There was no role of other VDR variants (BsmI, TaqI, and ApaI). FokI mutation and diminished vitamin D increase the likelihood of developing BC.

Vitamin D as therapeutic modulator in cerebrovascular diseases: a mechanistic perspectives

Vitamin D deficiency has been linked to several major chronic diseases, such as cardiovascular and neurodegenerative diseases, diabetes, and cancer, linked to oxidative stress, inflammation, and aging. Vitamin D deficiency appears to be particularly harmful to the cardiovascular system, as it can cause endothelial dysfunctioning and vascular abnormalities through the modulation of various downstream mechanisms. As a result, new research indicates that therapeutic approaches targeting vitamin D inadequacies or its significant downstream effects, such as impaired autophagy, abnormal pro-inflammatory and pro-oxidant reactions, may delay the onset and severity of major cerebrovascular disorders such as stroke and neurologic malformations. Vitamin D modulates the various molecular pathways, i.e., Nitric Oxide, PI3K-Akt Pathway, cAMP pathway, NF-kB Pathway, Sirtuin 1, Nrf2, FOXO, in cerebrovascular disorder. The current review shows evidence for vitamin D's mitigating or slowing the progression of these cerebrovascular disorders, which are significant causes of disability and death worldwide.

Does vitamin D deficiency predict tumour malignancy in patients with bone tumours? Data from a multi-center cohort analysis

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Vitamin D deficiency is common in patients with bone tumours.

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Potential association between pre-diagnostic vitamin D status and tumour malignancy in patients with bone tumours.

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25(OH)D status should routinely be assessed and monitored in patients with bone tumours.

Vitamin D deficiency is a global health concern that is estimated to afflict over one billion people globally. The major role of vitamin D is that of a regulator of calcium and phosphate metabolism, thus, being essential for proper bone mineralisation. Concomitantly, vitamin D is known to exert numerous extra-skeletal actions. For example, it has become evident that vitamin D has direct anti-proliferative, pro-differentiation and pro-apoptotic actions on cancer cells. Hence, vitamin D deficiency has been associated with increased cancer risk and worse prognosis in several malignancies. We have recently demonstrated that vitamin D deficiency promotes secondary cancer growth in bone. These findings were partly attributable to an increase in bone remodelling but also through direct effects of vitamin D on cancer cells. To date, very little is known about vitamin D status of patients with bone tumours in general. Thus, the objective of this study was to assess vitamin D status of patients with diverse bone tumours. Moreover, the aim was to elucidate whether or not there is an association between pre-diagnostic vitamin D status and tumour malignancy in patients with bone tumours.

In a multi-center analysis, 25(OH)D, PTH and calcium levels of 225 patients that presented with various bone tumours between 2017 and 2018 were assessed. Collectively, 76% of all patients had insufficient vitamin D levels with a total mean 25(OH)D level of 21.43 ng/ml (53.58 nmol/L). In particular, 52% (117/225) of patients were identified as vitamin D deficient and further 24% of patients (55/225) were vitamin D insufficient. Notably, patients diagnosed with malignant bone tumours had significantly lower 25(OH)D levels than patients diagnosed with benign bone tumours [19.3 vs. 22.75 ng/ml (48.25 vs. 56.86 nmol/L); p = 0.04).

In conclusion, we found a widespread and distressing rate of vitamin D deficiency and insufficiency in patients with bone tumours. However, especially for patients with bone tumours sufficient vitamin D levels seem to be of great importance. Thus, we believe that 25(OH)D status should routinely be monitored in these patients. Collectively, there should be an increased awareness for physicians to assess and if necessary correct vitamin D status of patients with bone tumours in general or of those at great risk of developing bone tumours.

Hospital-Based Preliminary Observations of Dietary Intake and Physical Activity in Saudi Patients with Colorectal Polyps: A Call for Nutrition Care Integration after Polypectomy Procedure

Aim: In Saudi Arabia, the incidence of colorectal cancer (CRC) is increasing. Lifestyle modification, including diet and physical activity, is as important as the standard procedure of colonoscopy screening in reducing CRC development. I explored the dietary intake, physical activity, and selected nutritional biomarkers in Saudi patients with colorectal polyps, a precursor of CRC. Methods: Thirty polypectomy patients (aged 35–84 years) were recruited from an endoscopy unit at King Abdulaziz University Hospital. Demographic, anthropometric, physical activity, and food frequency data were collected. Plasma C-reactive protein, serum 25-hydroxy vitamin D, and folate levels were measured. Results: The median body mass index (BMI) of the patients was within the overweight cut-off range. The median consumption of carbohydrate and protein was within the recommended dietary allowance (RDA). Median fat consumption was above the RDA, while median fiber intake was below the RDA. Patients met the recommended servings/day of fruits, vegetables, dairy products, and protein but exceeded the recommended intake of fats and sweets. Most patients were non-active, with an inadequate level of serum vitamin D. Conclusion: We observed several risk factors previously associated with CRC, including low levels of physical activity, serum vitamin D, and fiber intake, and high BMI and fat intake among polypectomy patients.

25-hydroxyvitamin D in malignant pleural disease: a prospective cohort study

INTRODUCTION

Growing evidence suggests a role of vitamin D in various cancers but the significance of vitamin D in malignant pleural disease remains unexplored. We sought to investigate the concentration and diagnostic role of 25-hydroxyvitamin D (25(OH)D) in malignant pleural effusions.

MATERIALS AND METHODS

Prospective study of consecutive treatment-naïve patients with a new diagnosis of pleural effusion.

RESULTS

Seventy-eight patients were studied, 45 of whom had malignant pleural effusions. Concentration of 25(OH)D in pleural fluid was significantly higher than serum in both malignant (15.2 ng/mL (9.7, 25.6) versus 10.2 ng/mL (6.4, 17.7), P < .001) and benign (11.4 ng/mL (8.4, 23.6) versus 7.9 (5.9, 16.1), P < .001) pleural disease. Pleural fluid 25(OH)D was almost significantly higher in exudates compared to transudates (P = .050) but it did not differ significantly between malignant and benign effusions (P = .217) and it was not diagnostic for malignant pleural disease (area under the ROC curve .58, 95% CI .45-.71).

CONCLUSIONS

In subjects with unselected pleural effusions, 25(OH)D in pleural fluid was not diagnostic for malignant pleural disease. The novel finding of convincingly and consistently higher 25(OH)D in pleural fluid than serum suggests a role for vitamin D in pleural disease and merits further research.

Nontargeted identification of peptides and disinfection byproducts in water

A broad range of organic compounds are known to exist in drinking water sources and serve as precursors of disinfection byproducts (DBPs). Epidemiological findings of an association of increased risk of bladder cancer with the consumption of chlorinated water has resulted in health concerns about DBPs. Peptides are thought to be an important category of DBP precursors in water. However, little is known about the actual presence of peptides and their DBPs in drinking water because of their high sample complexity and low concentrations. To address this challenge and identify peptides and non-chlorinated/chlorinated peptide DBPs from large sets of organic compounds in water, we developed a novel high throughput analysis strategy, which integrated multiple solid phase extraction (SPE), high performance liquid chromatography (HPLC) separation, and non-target identification using precursor ion exclusion (PIE) high resolution mass spectrometry (MS). After MS analysis, structures of candidate compounds, particularly peptides, were obtained by searching against the Human Metabolome Database (HMDB). Using this strategy, we successfully detected 625 peptides (out of 17,205 putative compounds) and 617 peptides (out of 13,297) respectively in source and finished water samples. The source and finished water samples had 501 peptides and amino acids in common. The remaining 116 peptides and amino acids were unique to the finished water. From a subset of 30 putative compounds for which standards were available, 25 were confirmed using HPLC-MS analysis. By analyzing the peptides identified in source and finished water, we successfully confirmed three disinfection reaction pathways that convert peptides into toxic DBPs.

The dangers of hazards

Concerns about the quality and reproducibility of scientific papers have emphasised the uncertainty of observations in the biological sciences. Focussing on this problem in the types of science that often underlie regulations affecting population exposures has clear implications for regulatory studies. Recent comments on the IARC process of hazard identification in the field of carcinogenesis have identified problems in dealing with public information content and regulatory value of the Monograph system. What is the value of a system that does not clearly identify its methodology for defining a hazard and which does not provide realistic estimates of risk?

Vitamin D status among patients visiting a tertiary care center in Riyadh, Saudi Arabia: a retrospective review of 3475 cases

BACKGROUND

Vitamin D deficiency has been implicated in several chronic, non-communicable diseases independent of its conventional role in bone and calcium homeostasis. In this retrospective study, we determined the prevalence of vitamin D deficiency and its association to several cardiometabolic indices among patients visiting King Abdulaziz Medical City (KAMC), a tertiary hospital in Riyadh, Saudi Arabia.

METHODS

A total of 3475 charts of out-patient subjects who visited KAMC from September 2009 until December 2010 were reviewed and included. Variables of interest included measurements of vitamin D status, glycemic and renal profile, as well as trace elements (calcium and phosphorous).

RESULTS

The over-all prevalence of vitamin D deficiency in the cohort studied was 78.1% in females and 72.4% in males. 25(OH) vitamin D was significantly associated with increasing age and weight (p-values < 0.0001 and 0.005, respectively). It was also positively associated with albumin, calcium and phosphorous (p-values < 0.0001, < 0.0001 and 0.0007, respectively) and negatively associated with alkaline phosphatase as well as circulating levels of PTH (p-values 0.0002 and 0.0007, respectively).

CONCLUSION

In conclusion, vitamin D deficiency is overwhelmingly common among patients seen at KAMC regardless of the medical condition, and it is significantly associated with increasing age, weight and markers of calcium homeostasis. Findings of the present study further stress the spotlight on vitamin D deficiency epidemic in the country and region in general.

Vitamin D deficiency is widespread in cancer patients and correlates with advanced stage disease: a community oncology experience

The purpose of this study was to correlate serum vitamin D levels with potential clinical variables and to determine the extent of vitamin D deficiency in a large, outpatient oncology practice. One hundred ninety-five consecutive patients referred for consultation at a community radiation oncology center from October 8, 2008 to March 17, 2010 had vitamin D levels ordered. Patients who were deficient in vitamin D were treated with replacement therapy. Demographic and medical data were collected prospectively and subsequently analyzed. Pretreatment baseline patient and tumor characteristics were evaluated with respect to vitamin D concentrations. One hundred and sixty patients were analyzed. A total of 74% of patients had 25-hydroxyvitamin D concentrations considered either deficient (<20 ng/mL) or suboptimal (20-30 ng/mL). Replacement therapy raised serum vitamin D levels by an average of 15 ng/mL (95% CI = 11-18, P < 0.01). Lower than median serum vitamin D levels were associated with stage III disease in univariate analysis [OR = 2.6 (95% CI = 1.1-6.2), p = 0.04] as well as multivariate analysis adjusted for age, sex, body mass index, and season of draw [OR = 3.3 (95% CI = 1.1-9.7), P = 0.03]. Three-quarters of patients in our series had suboptimal or deficient circulating concentrations of 25-hydroxyvitamin D. Low serum vitamin D levels, independent of age, sex, and body mass index, predicted advanced stage disease.

Availability of vitamin D photoconversion weighted UV radiation in southern South America

Ultraviolet radiation (UVR) plays a key role in several biological functions, including human health. Skin exposure to UVR is the main factor in vitamin D photoconversion. There is also evidence relating low levels of vitamin D with certain internal cancers, mainly colon, breast and prostate, as well as other diseases. Several epidemiological studies have shown an inverse relationship between the above-mentioned diseases and latitude, in accordance with the ultraviolet radiation latitudinal gradient. The aim of this study is to determine whether UV irradiance levels in the southern South America are sufficient to produce suitable levels of vitamin D year around. For this purpose, vitamin D photoconversion weighted-irradiance was analyzed between S.S. de Jujuy (24.17°S, 65.02°W) and Ushuaia (54° 50'S, 68° 18'W). In addition to irradiance, skin type and area of body exposed to sunlight are critical factors in vitamin D epidemiology. Due to a broad ethnic variability, it was assumed that the skin type in this region varies between II and V (from the most to the less sensitive). All sites except South Patagonia indicate that skin II under any condition of body area exposure and skin V when exposing head, hands, arms and legs, would produce suitable levels of vitamin D year round (except for some days in winter at North Patagonian sites). At South Patagonian sites, minimum healthy levels of vitamin D year round can be reached only by the more sensitive skin II type, if exposing head, hands, arms and legs, which is not a realistic scenario during winter. At these southern latitudes, healthy vitamin D levels would not be obtained between mid May and beginning of August if exposing only the head. Skin V with head exposure is the most critical situation; with the exception of the tropics, sun exposure would not produce suitable levels of vitamin D around winter, during a time period that varies with latitude. Analyzing the best exposure time during the day in order to obtain a suitable level of vitamin D without risk of sunburn, it was concluded that noon is best during winter, as determined previously. For skin type II when exposing head, exposure period in winter varies between 30 and 130 min, according to latitude, except for South Patagonian sites. During summer, noon seems to be a good time of day for short periods of exposure, while during leisure times, longer periods of exposure without risk of sunburn are possible at mid-morning and mid-afternoon. At 3 h from noon, solar zenith angles are almost the same for sites between the tropics and North Patagonia, and at 4 h from noon, for all sites. Then, in these cases, the necessary exposure periods varied slightly between sites, only due to meteorological differences.

An estimate of the global reduction in mortality rates through doubling vitamin D levels

BACKGROUND/OBJECTIVES

The goal of this work is to estimate the reduction in mortality rates for six geopolitical regions of the world under the assumption that serum 25-hydroxyvitamin D (25(OH)D) levels increase from 54 to 110 nmol/l.

SUBJECTS/METHODS

This study is based on interpretation of the journal literature relating to the effects of solar ultraviolet-B (UVB) and vitamin D in reducing the risk of disease and estimates of the serum 25(OH)D level-disease risk relations for cancer, cardiovascular disease (CVD) and respiratory infections. The vitamin D-sensitive diseases that account for more than half of global mortality rates are CVD, cancer, respiratory infections, respiratory diseases, tuberculosis and diabetes mellitus. Additional vitamin D-sensitive diseases and conditions that account for 2 to 3% of global mortality rates are Alzheimer's disease, falls, meningitis, Parkinson's disease, maternal sepsis, maternal hypertension (pre-eclampsia) and multiple sclerosis. Increasing serum 25(OH)D levels from 54 to 110 nmol/l would reduce the vitamin D-sensitive disease mortality rate by an estimated 20%.

RESULTS

The reduction in all-cause mortality rates range from 7.6% for African females to 17.3% for European females. Reductions for males average 0.6% lower than for females. The estimated increase in life expectancy is 2 years for all six regions.

CONCLUSIONS

Increasing serum 25(OH)D levels is the most cost-effective way to reduce global mortality rates, as the cost of vitamin D is very low and there are few adverse effects from oral intake and/or frequent moderate UVB irradiance with sufficient body surface area exposed.

Prospective study of UV exposure and cancer incidence among Swedish women

BACKGROUND

Except for skin melanoma and nonmelanoma skin cancer, little evidence from prospective studies is available on the association between UV exposure and cancer risk.

METHODS

We followed prospectively 49,261 women aged 30 to 49 years at enrollment in 1991 to 1992 for 15 years. Cancer incidence was analyzed by fitting Cox models, and estimating hazard ratios (HR) and 95% confidence intervals (CI).

RESULTS

2,303 incident cases of cancer were diagnosed (breast: 1,053, ovary: 126, lung: 116, colon-rectum: 133, and brain: 116). No associations were found between any cumulative measure of UV exposure at ages 10 to 39 years and overall cancer risk. However, spending ≥1 week/year between ages 10 and 29 years on sunbathing vacations led to an inverse association with overall cancer risk (HR: 0.70, 95% CI: 0.53-0.93) and breast cancer risk (HR: 0.56, 95% CI: 0.36-0.89) when compared with women who never went on such vacations. Solarium use was inversely associated with breast cancer risk, whereas ≥2 sunburns/year was inversely associated with lung cancer risk. No other associations were found between sun exposure or solarium use at ages 10 to 39 years and cancer risk.

CONCLUSION

We found no evidence of an association between any cumulative measure of UV exposure at ages 10 to 39 years and overall cancer risk. UV exposure earlier in life was related to reduced overall and breast cancer risk.

IMPACT

Further research is needed to define the amount of solar or artificial UV exposure that may, or may not, be beneficial for cancer prevention.

Requirements for Vitamin D Across the Life Span

Adequate provision of vitamin D has been found, in ecological, cross-sectional, and observational studies, to be associated with reduction in the risk of many types of cancer, cardiovascular diseases (CVDs), autoimmune diseases, diabetes mellitus types 1 and 2, neurological disorders, several bacterial and viral infections, and adverse pregnancy outcomes in addition to the classical bone disorders of rickets and osteomalacia. Furthermore, investigators have found adequate repletion and increased intakes of vitamin D to be associated with reduced all-cause mortality rates. These findings have been supported by the limited number of properly conducted randomized controlled trials (RCTs) that used more than 400 IU/day of vitamin D. This review presents an overview of the role of vitamin D for the promotion of health for the more important vitamin D-related diseases and conditions. Serum 25-hydroxyvitamin D concentrations of 30—60 ng/ml, corresponding to oral intake or skin production of 1,000—4,000 IU/day of vitamin D, appear necessary in adults for avoidance of hypovitaminosis D-related ill health. People of all ages are encouraged to obtain more vitamin D from judicious exposure to sunshine (for ultraviolet B [UVB] irradiation) or from regular vitamin D supplements because dietary sources do not provide sufficient vitamin D to prevent any health risks other than those of rickets and osteomalacia.

The human health effects of ozone depletion and interactions with climate change

Depletion of the stratospheric ozone layer has led to increased solar UV-B radiation (280-315 nm) at the surface of the Earth. This change is likely to have had an impact on human exposure to UV-B radiation with consequential detrimental and beneficial effects on health, although behavioural changes in society over the past 60 years or so with regard to sun exposure are of considerable importance. The present report concentrates on information published since our previous report in 2007. The adverse effects of UV radiation are primarily on the eye and the skin. While solar UV radiation is a recognised risk factor for some types of cataract and for pterygium, the evidence is less strong, although increasing, for ocular melanoma, and is equivocal at present for age-related macular degeneration. For the skin, the most common harmful outcome is skin cancer, including melanoma and the non-melanoma skin cancers, basal cell carcinoma and squamous cell carcinoma. The incidence of all three of these tumours has risen significantly over the past five decades, particularly in people with fair skin, and is projected to continue to increase, thus posing a significant world-wide health burden. Overexposure to the sun is the major identified environmental risk factor in skin cancer, in association with various genetic risk factors and immune effects. Suppression of some aspects of immunity follows exposure to UV radiation and the consequences of this modulation for the immune control of infectious diseases, for vaccination and for tumours, are additional concerns. In a common sun allergy (polymorphic light eruption), there is an imbalance in the immune response to UV radiation, resulting in a sun-evoked rash. The major health benefit of exposure to solar UV-B radiation is the production of vitamin D. Vitamin D plays a crucial role in bone metabolism and is also implicated in protection against a wide range of diseases. Although there is some evidence supporting protective effects for a range of internal cancers, this is not yet conclusive, but strongest for colorectal cancer, at present. A role for vitamin D in protection against several autoimmune diseases has been studied, with the most convincing results to date for multiple sclerosis. Vitamin D is starting to be assessed for its protective properties against several infectious and coronary diseases. Current methods for protecting the eye and the skin from the adverse effects of solar UV radiation are evaluated, including seeking shade, wearing protective clothing and sunglasses, and using sunscreens. Newer possibilities are considered such as creams that repair UV-induced DNA damage, and substances applied topically to the skin or eaten in the diet that protect against some of the detrimental effects of sun exposure. It is difficult to provide easily understandable public health messages regarding "safe" sun exposure, so that the positive effects of vitamin D production are balanced against the negative effects of excessive exposure. The international response to ozone depletion has included the development and deployment of replacement technologies and chemicals. To date, limited evidence suggests that substitutes for the ozone-depleting substances do not have significant effects on human health. In addition to stratospheric ozone depletion, climate change is predicted to affect human health, and potential interactions between these two parameters are considered. These include altering the risk of developing skin tumours, infectious diseases and various skin diseases, in addition to altering the efficiency by which pathogenic microorganisms are inactivated in the environment.

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.

Health benefits of higher serum 25-hydroxyvitamin D levels in The Netherlands

A large and rapidly expanding body of scientific literature exists on the roles of vitamin D in maintaining optimal health and reducing the risk of chronic and infectious diseases. Serum 25-hydroxyvitamin D [25(OH)D] levels for optimal health are in the range of 100-150 nmol/L; mean population values in The Netherlands are around 50-63 nmol/L. Health problems for which there exists good observational evidence and some randomized controlled trial evidence that vitamin D reduces risk include many types of cancer, cardiovascular disease, diabetes mellitus, bacterial and viral infections, autoimmune diseases, osteoporosis, falls and fractures, dementia, congestive heart failure, and adverse pregnancy outcomes. Reductions in incidence and mortality rates for various diseases and all-cause mortality rates can be determined from ecological, observational and cross-sectional studies and randomized controlled trials. For The Netherlands, raising mean serum 25(OH)D levels to 105 nmol/L is estimated to reduce specific disease rates by 10-50% and all-cause mortality rates by 18%. To raise serum 25(OH)D levels by this amount, inhabitants in The Netherlands would have to increase vitamin D production or oral intake by 2500-4000 IU/day. Doing so would pose only minimal increased risks of melanoma or skin cancer or hypercalcemia.

Relation between prediagnostic serum 25-hydroxyvitamin D level and incidence of breast, colorectal, and other cancers

The evidence is increasing that higher serum 25-hydroxyvitamin D [25(OH)D] levels reduce the risk of many types of cancer. Ecological and observational studies yield the strongest evidence, with support from studies of mechanisms. A key question is identifying the relation between serum 25(OH)D level and cancer incidence. Meta-analyses of such studies is a reasonable approach to determine the serum 25(OH)D level-cancer incidence relation. This paper reports new meta-analyses for breast and colorectal cancers. Currently, the journal literature offers seven prospective breast cancer and ten prospective colorectal cancer studies that can be used. The data for these studies graphed and compared. Data from some of the studies were multiplied by factors to bring all the studies into reasonable agreement with a tentative dose-response relation. The data were fit with a variety of functions; the best fits were nonlinear functions that tended to asymptotically reach a lower odds ratio at higher serum 25(OH)D levels. These analyses estimated that the 50% reduction in incidence occurs for a value of 78 nmol/L compared with the value at 24 nmol/L for breast cancer, and a value of 60 nmol/L compared with the value at 15 nmol/L for colorectal cancer. Although these results are reasonable, some concern exists that a single serum 25(OH)D level, measured years prior to diagnosis of cancer, does not adequately represent the serum levels for the entire period before diagnosis. Future prospective studies should include more serum 25(OH)D level measurements during the study course.

Dr. Frank caldwell garland, june 20, 1950-august 17, 2010

Frank Caldwell Garland, Ph.D., died August 17, 2010 after a year-long battle with cancer. He will be remembered for his seminal work with his brother Cedric F. Garland in proposing the ultraviolet-B (UVB)-vitamin D-cancer hypothesis to explain the geographical variation of colon cancer mortality rates in the United States in 1980. This hypothesis has been extended to about 20 types of cancer using the ecological approach, and supported strongly by observational studies of prediagnostic serum 25-hydroxyvitamin D [25(OH) D] for incidence of breast, colorectal and ovarian cancer, and a randomized controlled trial that used sufficient vitamin D (1,150 IU/day) to and found a strongly beneficial effect on cancer incidence. The UVB-vitamin D-cancer hypothesis is also supported by studies that used as the index of solar UVB irradiance the amount of sunlight exposure in childhood or incidence of non-melanoma skin cancer. Survival after diagnosis was increased for individuals with higher serum 25(OH)D levels at the time of cancer diagnosis for six types of cancer: breast, colorectal, lung and prostate cancer; melanoma and non-Hodgkin's lymphoma. The ecological study approach is ideally suited to studying cancer risk-modifying factors since the lag between cancer initiation and detection or death can be 20-40 years or more, making ordinary observational studies difficult. The impact on vitamin D research by both Frank Garland and Cedric Garland has been immense. Health policy leaders will realize this in the near future, providing a rich legacy for humanity.

An ecological study of cancer incidence and mortality rates in France with respect to latitude, an index for vitamin D production

France has unexplained large latitudinal variations in cancer incidence and mortality rates. Studies of cancer rate variations in several other countries, as well as in multicountry studies, have explained such variations primarily in terms of gradients in solar ultraviolet-B (UVB) doses and vitamin D production. To investigate this possibility in France, I obtained data on cancer incidence and mortality rates for 21 continental regions and used this information in regression analyses with respect to latitude. This study also used dietary data. Significant positive correlations with latitude emerged for breast, colorectal, esophageal (males), lung (males), prostate, both uterine cervix and uterine corpus, all and all less lung cancer. Although correlations with latitude were similar for males and females, the regression variance for all and all less lung cancer was about twice as high for males than for females. Lung cancer incidence and mortality rates for females had little latitudinal gradient, indicating that smoking may have also contributed to the latitudinal gradients for males. On the basis of the available dietary factor, micro- and macronutrient data, dietary differences do not significantly affect geographical variation in cancer rates. These results are consistent with solar UVB's reducing the risk of cancer through production of vitamin D. In the context of serum 25-hydroxyvitamin D level-cancer incidence relations, cancer rates could be reduced significantly in France if everyone obtained an additional 1,000 IU/day of vitamin D. Many other benefits of vitamin D exist as well.

An ecological study of cancer mortality rates in the United States with respect to solar ultraviolet-B doses, smoking, alcohol consumption and urban/rural residence

The Cohort Consortium Vitamin D Polling Project of Rarer Cancers (VDPP ) study failed to find a beneficial role of prediagnostic serum 25-hydroxyvitamin D [25(OH)D] levels on risk of seven types of rarer cancer: endometrial, esophageal, gastric, kidney, ovarian and pancreatic cancer and non-Hodgkin's lymphoma (NHL). However, ecological studies and studies of oral vitamin D intake have generally found solar ultraviolet B (UVB) and oral vitamin D inversely correlated with incidence and/or mortality rates of these cancers. To explore the discrepancy, I conducted an ecological study of cancer mortality rates for white Americans in the United States for 1950-1994 with data for 503 state economic areas in multiple linear regression analyses with respect to UVB for July, lung cancer, alcohol consumption and urban/rural residence. UVB was significantly inversely correlated with six types of cancer (not pancreatic cancer) in both periods. However, the adjusted R(2) values were much lower for cancers with lower mortality rates than those in an earlier ecological study that used state-averaged data. This finding suggests that the VDPP study may have had too few cases. Thus, the VDPP study should not be considered as providing strong evidence against the solar UVB-vitamin D-cancer hypothesis.

Are Hill's criteria for causality satisfied for vitamin D and periodontal disease?

There is mounting evidence that periodontal disease (PD) is linked to low serum 25-hydroxyvitamin D [25(OH)D] concentrations in addition to recognized risk factors like diet and smoking. This paper reviews this evidence using Hill's criteria for causality in a biological system. Evidence for strength of association, consistency, cohesion and 'dose-effects' [biological 'gradients'] include strong inverse correlations between serum 25(OH) and PD cross-sectionally and that PD is consistently more prevalent in darker vs. lighter skinned people and increases at higher latitudes with analogy for gingivitis and for disorders associated with PD whose risks also increase with hypovitaminosis D. Evidence for plausibility includes that vitamin D increases calcium absorption and protects bone strength; induces formation of cathelicidin and other defensins that combat bacterial infection; reduces tissue production of destructive matrix metalloproteinases actively associated with PD and that prevalence of PD varies with common vitamin D receptor polymorphisms. Experimental evidence from limited supplementation studies [using calcium and vitamin D] shows that supplementation reduces tooth loss. Thus, existing evidence for hypovitaminosis D as a risk factor for PD to date meets Hill's criteria for causality in a biological system. Further experimental evidence for effectiveness and temporality, preferably from randomized controlled trials of vitamin D supplementation [adjusting for other PD risk factors including diet and smoking to reduce confounding] are necessary to confirm causality. If confirmed, dentists and periodontists could perform a valuable service to their patients by discussing the importance of adequate vitamin D status and how to avoid deficiency.

Critique of the U-shaped serum 25-hydroxyvitamin D level-disease response relation

Previous work has suggested an optimal serum 25-hydroxyvitamin D [25(OH)D] level near 20-30 ng/mL, above which disease risk may increase. Although based primarily on a prostate cancer study in Nordic countries, examples include esophageal, and pancreatic cancer, cardiovascular disease, and all-cause mortality rate. However, these studies apparently are not representative of the findings in the literature for these diseases or disease outcome in general. The prostate cancer study was from Nordic countries and used serum 25(OH)D levels from more than 15 years prior to cancer diagnosis for about half of the cases. Most studies of prediagnostic serum 25(OH)D find no significant correlation with risk of prostate cancer. Many risk-modifying factors for prostate cancer exist that observational studies generally do not include. The esophageal cancer data were from a region of China with high incidence of esophageal cancer. The pancreatic study was conducted on smokers in Finland. Both the esophageal and pancreatic studies are at odds with many ecological and observational studies in various countries. When several studies for cardiovascular disease, and all-cause mortality rate are combined in preliminary meta-analyses, the best fits to the data show a monotonic decrease of hazard ratio with increasing logarithm of serum 25(OH)D. Thus, little support exists for the U-shaped serum 25(OH)D level-disease response relation, and the few studies that do should not be used in forming public health policies regarding vitamin D and ultraviolet-B irradiance.

Critique of the International Agency for Research on Cancer's meta-analyses of the association of sunbed use with risk of cutaneous malignant melanoma

The International Agency for Research on Cancer (IARC) reported meta-analyses of the association of cutaneous malignant melanoma (CMM), finding significant correlations with ever use of sunbeds and first use of sunbeds prior to age 35 years; it did not claim that the associations showed causal links. However, some observational studies in the meta-analysis included individuals in the UK with skin phenotype at increased genetic risk of CMM without adjustment for skin phenotype. Treating the five UK studies separately from the other 14 corrected this oversight. In the original study, the summary relative risk (RR ) of CMM with respect to sunbed use was 1.15 (95% confidence interval [CI], 1.00-1.31). In this study, the similar RR was 1.20 (95% CI, 1.03-1.38). The RR for the five UK studies was 2.09 (95% CI, 1.14-3.84), whereas the RR for the other 14 studies was 1.09 (95% CI, 0.96-1.24). For first use of sunbeds prior to age 35 years, the IARC found a summary RR of 1.75 (95% CI, 1.35-2.36). This study plotted the RRs versus latitude of each study population, with a linear regression analysis carried out for all but the one UK study. The RR increased at 0.077 per degree of latitude and the regression explained 67% of the variance. It is also argued that factors other than sunbed use explain the increasing worldwide trends in CMM. Because solar-UV-simulating sunbeds induce production of vitamin D, the health benefits of their use greatly outweigh any possible risks.

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.

In defense of the sun: An estimate of changes in mortality rates in the United States if mean serum 25-hydroxyvitamin D levels were raised to 45 ng/mL by solar ultraviolet-B irradiance

Emerging scientific evidence strongly supports the beneficial role of vitamin D in reducing the risk of incidence and death from many chronic and infectious diseases. This study estimates increases in melanoma and nonmelanoma skin cancer mortality rates and decreases in chronic and infectious disease mortality rates in the US from the standpoint of approximately doubling population doses of solar UVB to increase mean serum 25-hydroxyvitamin D levels from 16 ng/mL for black Americans and 25 ng/mL for white Americans to 45 ng/mL. The primary benefits are expected to come from reductions in cancer and cardiovascular diseases. Although a few thousand excess deaths per year might occur from melanoma and skin cancer, the avoided premature death rate could be near 400,000/ year, with most of the avoided deaths coming late in life. While oral sources of vitamin D could be used instead of UVB or when UVB irradiance is not available, public health policies do not yet recommend the 3,000-4,000 IU/day required to raise serum 25-hydroxyvitamin D levels to the levels required for optimal health, which would be required before vitamin D fortification levels in food can be raised. Until then, moderate solar UVB irradiance remains an import source, and the health benefits greatly outweigh the risks.

Estimated benefit of increased vitamin D status in reducing the economic burden of disease in western Europe

Vitamin D has important benefits in reducing the risk of many conditions and diseases. Those diseases for which the benefits are well supported and that have large economic effects include many types of cancer, cardiovascular diseases, diabetes mellitus, several bacterial and viral infections, and autoimmune diseases such as multiple sclerosis. Europeans generally have low serum 25-hydroxyvitamin D [25(OH)D] levels owing to the high latitudes, largely indoor living, low natural dietary sources of vitamin D such as cold-water ocean fish, and lack of effective vitamin D fortification of food in most countries. Vitamin D dose-disease response relations were estimated from observational studies and randomized controlled trials. The reduction in direct plus indirect economic burden of disease was based on increasing the mean serum 25(OH)D level to 40 ng/mL, which could be achieved by a daily intake of 2000-3000 IU of vitamin D. For 2007, the reduction is estimated at euro187,000 million/year. The estimated cost of 2000-3000 IU of vitamin D3/day along with ancillary costs such as education and testing might be about euro10,000 million/year. Sources of vitamin D could include a combination of food fortification, supplements, and natural and artificial UVB irradiation, if properly acquired. Additional randomized controlled trials are warranted to evaluate the benefits and risks of vitamin D supplementation. However, steps to increase serum 25(OH)D levels can be implemented now based on what is already known.