An ecologic study of dietary and solar ultraviolet-B links to breast carcinoma mortality rates

Dairy and dairy-related nutrient intake during middle childhood

OBJECTIVE

To characterize patterns of dairy intake among girls in middle childhood.

DESIGN

Longitudinal data were used to characterize girls' patterns of dairy intake at age 5, 7, 9, and 11 years.

SUBJECTS

Participants were 151 girls from predominately middle-class and exclusively non-Hispanic white families living in central Pennsylvania.

STATISTICAL ANALYSES

Intakes of dairy, energy, macronutrients, vitamin D, calcium, and phosphorus were assessed using three 24-hour dietary recalls in 151 non-Hispanic white girls at age 5, 7, 9, and 11 years. Analyses of changes over time were conducted using repeated measures analysis of variance. McNemar's chi(2) test was used to analyze change in percentage of dairy consumers over time.

RESULTS

From age 5 to 11 years, girls' total dairy intake remained stable. Total milk consumption declined, due to a decline in intake of milk as a beverage, while intakes of cheese and dairy desserts increased. Much of the decline in milk intake from age 5 to 11 years, especially for milk as a beverage, was due to a reduction in the percentage of girls consuming milk as a beverage, not simply due to a decline in the servings of milk as a beverage consumed by consumers. On average, girls met vitamin D recommendations over time; however, by age 9 and 11 years girls failed to meet calcium and phosphorus recommendations.

CONCLUSIONS

Although girls' dairy intake was stable over time, at age 7, 9, and 11 years girls did not meet the recommended three servings per day, leading to suboptimal intakes of calcium and phosphorus at age 9 and 11 years. Increasing milk intake among all children should continue to be a major focus of interventions.

Vitamin D fortification as public health policy: significant improvement in vitamin D status in young Finnish men

BACKGROUND

Vitamin D insufficiency is common in northern countries during wintertime. In Finland, after the recommendation by the Ministry of Social Affairs and Health, vitamin D has been added to liquid milk products and margarines from February 2003.

OBJECTIVE

We determined the effects of national policy on vitamin D fortification on vitamin D status among young Finnish men.

DESIGN

A comparison before and after intervention with study population of 196 young Finnish men (18-28 years) was carried out. Serum 25-hydroxyvitamin D3 (25-OHD3) concentrations were determined with the OCTEIA enzymeimmunoassay by IDS (Immunodiagnostic Systems Limited, Bolden, UK) in January 2003 (n = 96) and in January 2004 (n = 100), nearly 1 year after national vitamin D fortification had started.

RESULTS

The mean serum 25-OHD3 concentrations during the wintertime increased by 50% after implementation of the vitamin D fortification of dairy products. Correspondingly, the prevalence of vitamin D insufficiency (serum 25-OHD3 < 40 nmol/l) was decreased by 50% from 78% in January 2003 to 35% in January 2004.

CONCLUSIONS

Our results demonstrate that national vitamin D fortification substantially improved the vitamin D status of young Finnish men. Still, a third remained vitamin D insufficient.

The role of vitamin D in cancer prevention

Vitamin D status differs by latitude and race, with residents of the northeastern United States and individuals with more skin pigmentation being at increased risk of deficiency. A PubMed database search yielded 63 observational studies of vitamin D status in relation to cancer risk, including 30 of colon, 13 of breast, 26 of prostate, and 7 of ovarian cancer, and several that assessed the association of vitamin D receptor genotype with cancer risk. The majority of studies found a protective relationship between sufficient vitamin D status and lower risk of cancer. The evidence suggests that efforts to improve vitamin D status, for example by vitamin D supplementation, could reduce cancer incidence and mortality at low cost, with few or no adverse effects.

Plasma 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D and risk of breast cancer

Several lines of evidence suggest that vitamin D may reduce incidence of breast cancer, but few epidemiologic studies have addressed the relation of plasma vitamin D metabolites to the risk of this disease. We prospectively examined the relationship between plasma levels of 25-hydroxyvitamin D [25(OH)D] and 1,25-dihydroxyvitamin D [1,25(OH)2D] and risk of breast cancer in a case-control study nested within the Nurses' Health Study cohort. Blood samples were collected from study participants in 1989-1990. Breast cancer cases developing between blood collection and June 1, 1996, were matched to cancer-free controls on the basis of age, menopausal status, and other factors. Stored plasma samples from 701 cases and 724 controls were available for metabolite analysis. Cases had a lower mean 25(OH)D level than controls (P=0.01), but mean 1,25(OH)2D levels were similar (P=0.49). High levels of both metabolites were associated with a nonsignificant lower risk of breast cancer. Women in the highest quintile of 25(OH)D had a relative risk of 0.73 (95% confidence interval=0.49-1.07; Ptrend=0.06) compared with those in the lowest quintile. For 1,25(OH)2D, the comparable relative risk was 0.76 (95% confidence interval=0.52-1.11; Ptrend=0.39). For both metabolites, the association was stronger in women ages 60 years and older, but results were not statistically significant. Our findings suggest that high levels of 25(OH)D, and perhaps 1,25(OH)2D, may be modestly associated with reduced risk of breast cancer.

Season of diagnosis is a prognostic factor in Hodgkin's lymphoma: a possible role of sun-induced vitamin D

Experimental studies show that vitamin D derivatives are potent anticarcinogenic factors. Epidemiological observations support this, and vitamin D sufficiency has been hypothesised to be an important risk-reducing factor in several forms of cancer. Vitamin D level exhibits seasonal variations. In the present work, we have investigated the effect of the season of diagnosis on the risk of death among Hodgkin's lymphoma patients diagnosed in Norway between 1964 and 2000. Risk estimates were calculated as relative risk (RR), with 95% confidence intervals (95% CI), using Cox regression model. Epidemiological data for this period indicate that season of diagnosis is a strong prognostic factor for Hodgkin's lymphoma, with ≈20% lower case fatality for patients diagnosed during autumn vs winter diagnosis (RR=0.783, 95% CI,−0.62 to 0.99; P=0.041). Notably, the improved autumnal survival rate was higher than 60% (RR=0.364, 95% CI, −0.15 to 0.87; P=0.025) for patients younger than 30 years. This finding may be related to higher endogenous levels of vitamin D in autumn, with a favourable influence on the conventional therapy.

Colon cancer and solar ultraviolet B radiation and prevention and treatment of colon cancer in mice with vitamin D and its Gemini analogs

It has been recognized that people who live at higher latitudes and who are vitamin D deficient are at higher risk of dying from many common cancers including colon cancer. To evaluate the role of vitamin D deficiency on colon tumor growth, Balb/c adult male mice were fed either a vitamin D sufficient or vitamin D deficient diet for 10 weeks. Mice were arranged into groups of six and each animal received subcutaneously 10(4) MC-26 cells in the posterior trunk. The tumor size was recorded daily. By day 9 there was a significant difference in tumor volume between the vitamin D sufficient and vitamin D deficient mice. By day 18 the vitamin D deficient animals had a tumor size that was 56% larger compared to the animals that were vitamin D sufficient. To determine whether treatment with active vitamin D analogs could further decrease colon tumor growth in a vitamin D sufficient state, groups of mice were treated with the novel 19-nor-Gemini compounds. The mice were fed a low calcium diet. Twenty-four hours after tumor implantation, the mice received, three times weekly, one of the vitamin D analogs or the vehicle. The group that received Gemini 1,25-dihydroxy-21(3-hydroxy-3-trifluoromethyl-4-trifluoro-butynyl)-19-nor-20S-cholecalciferol (3) showed a dose-dependent decrease in tumor volume. On day 19, at the dose level of 0.02microg molar equivalents (E), the tumor volume was reduced by 41% when compared to the control group. At the same time point, the hexadeuterated analog 1,25-dihydroxy-21(3-hydroxy-3-trifluoromethyl-4-trifluoro-butynyl)-26,27-hexadeutero-19-nor-20S-cholecalciferol (4), administered at the 10-fold lower dose of 0.002microgE, showed a 52% reduction in tumor volume (p<0.05), compared to the control group. Animals that received 1,25(OH)(2)D(3) at 0.002 and 0.02microg showed a trend in tumor volume reduction at the highest dose but the changes were not statistically significant. An evaluation of serum calcium concentrations revealed that the calcium levels were normal in all groups, except the group receiving 0.02microgE of 4. The results from these studies demonstrate that vitamin D deficiency may accelerate colon cancer growth and that novel Gemini analogs of 1,25(OH)(2)D(3) may be an effective new approach for colon cancer treatment.

Biological actions of extra-renal 25-hydroxyvitamin D-1alpha-hydroxylase and implications for chemoprevention and treatment

The Vitamin D-activating enzyme 25-hydroxyvitamin D-1alpha-hydroxylase (1alpha-hydroxylase) is now known to be expressed in a much wider range of tissues that previously thought, suggesting a role for 1,25-dihydroxyvitamin D(3) (1,25(OH)(2)D(3)), which is more in keeping with a cytokine than a hormone. In this capacity, the function of 1alpha-hydroxylase in tumors is far from clear. Studies from several groups including ours have shown altered expression of 1alpha-hydroxylase in different types of neoplasm including breast, prostate and colon cancers. However, functional analysis of Vitamin D metabolism in cancer is complicated by the heterogenous composition of tumors. Immunohistochemical analysis of breast tumors has shown that 1alpha-hydroxylase is expressed by both epithelial cells and by tumor-infiltrating macrophages, suggesting an immunomodulatory component to 1,25(OH)(2)D(3) production in some types of cancer. The demonstration of 1alpha-hydroxylase activity in tumors and their equivalent normal tissues has implications for both the treatment and prevention of cancers. For example, in tumors chemotherapy options may include the use of non-1alpha-hydroxylated Vitamin D analogs to increase local concentrations of active metabolites without systemic side-effects. The role of 1alpha-hydroxylase in protection against cancer is likely to be more complicated and may involve anti-tumor immune responses.

Bioavailability of vitamin D2 from irradiated mushrooms: an in vivo study

Vitamin D2 from irradiated edible mushrooms might present a possible dietary source of this vitamin, subject to its bioavailability. Having previously optimized a method for the conversion of ergosterol in mushrooms to vitamin D2, this paper examines the vitamin D-enriched mushrooms (Lentinula edodes) for their bioavailability of the vitamin, using an animal model. Thirty male Wistar rats were fed for 1 week with a diet deficient in vitamin D. After this 1-week period, six rats were randomly selected and killed for analysis of initial bone mineral density, and serum level of 25-hydroxyvitamin D. A group of twelve rats of the test animals received 1 mug of vitamin D2 from irradiated mushrooms for a period of 4 weeks until being killed. The remaining twelve rats were fed un-irradiated mushrooms at the same level to act as controls. At the end of a 4-week period, the mean serum 25-hydroxyvitamin D level of the experimental group was 129.42 (sd 22.00) nmol/l whereas it was only 6.06 (sd 1.09) nmol/l in the control group. Femur bone mineral density of the experimental group of animals was significantly higher (P<0.01) than the control group. In addition, serum Ca concentrations among groups were shown to be significantly higher (P<0.01). It may be concluded from the results that vitamin D2 from UV-irradiated mushrooms is well absorbed and metabolized in this model animal system. Significant increase in femur bone mineralization (P<0.01) was shown in the presence of vitamin D2 from irradiated mushrooms compared with the controls.

Vitamin D: More than just affecting calcium and bone

Vitamin D is a fat-soluble steroid that is essential for maintaining normal calcium metabolism. In vitamin D deficiency, calcium absorption is insufficient and cannot satisfy the body's needs. Consequently, parathyroid hormone production increases and calcium is mobilized from bones and reabsorbed in the kidneys to maintain normal serum calcium levels--a condition defined as secondary hyperparathyroidism. Most organs, including the gut, brain, heart, pancreas, skin, kidneys, and immune system have receptors for 1,25 (OH)vitamin D. Furthermore, all of these organs have the capacity to synthesize 1,25 (OH)vitamin D from vitamin D. Extensive research suggests that vitamin D deficiency is common and represents a global health problem. Clinical consequences related to low vitamin D levels include not only osteomalacia, osteoporosis, and rickets, but also neuro-muscular dysfunction and fractures. Falls related to neuromuscular dysfunction lead to 40% of all nursing home admissions and are the largest single cause of injury-related deaths in elderly people. About one-third of all persons 65 and older fall at least once a year, resulting in more than 1.5 million emergency room treatments and more than 300,000 hospitalizations. Falls cause more than 11,000 deaths per year, most of them in elderly patients (> or = 75 years) who suffer hip fractures. It is well established that vitamin D deficiency not only has serious consequences for bone health, but also for other organ systems. Previous studies have shown that vitamin D supplementation reduces the number of fractures and directly improves neuromuscular function, thus helping to prevent falls and subsequent fractures. In addition, vitamin D appears to have other important functions as a regulator of cell differentiation and cell growth.

Vitamin D and Calcium Intakes from Food or Supplements and Mammographic Breast Density

BACKGROUND

A better understanding of factors that affect breast density, one of the strongest breast cancer risk indicators, may provide important clues about breast cancer etiology and prevention. This study evaluates the association of vitamin D and calcium, from food and/or supplements, to breast density in premenopausal and postmenopausal women separately.

METHODS

A total of 777 premenopausal and 783 post-menopausal women recruited at two radiology clinics in Quebec City, Canada, in 2001 to 2002, completed a food frequency questionnaire to assess vitamin D and calcium. Breast density from screening mammograms was assessed using a computer-assisted method. Associations between vitamin D or calcium and breast density were evaluated using linear regression models. Adjusted means in breast density were assessed according to the combined daily intakes of the two nutrients using generalized linear models.

RESULTS

In premenopausal women, total intakes of vitamin D and calcium were inversely related to breast density (beta = -1.4; P = 0.004 for vitamin D; beta = -0.8; P = 0.0004 for calcium). In multivariate linear regression, simultaneous increments in daily total intakes of 400 IU vitamin D and 1,000 mg calcium were associated with an 8.5% (95% confidence interval, 1.8-15.1) lower mean breast density. The negative association between dietary vitamin D intake and breast density tended to be stronger at higher levels of calcium intake and vice versa. Among postmenopausal women, intakes of vitamin D and calcium were not associated with breast density.

CONCLUSION

These findings show that higher intakes of vitamin D and calcium from food and supplements are related to lower levels of breast density among premenopausal women. They suggest that increasing intakes of vitamin D and calcium may represent a safe and inexpensive strategy for breast cancer prevention.

Vitamin D and calcium deficits predispose for multiple chronic diseases

There is evidence from both observational studies and clinical trials that calcium malnutrition and hypovitaminosis D are predisposing conditions for various common chronic diseases. In addition to skeletal disorders, calcium and vitamin D deficits increase the risk of malignancies, particularly of colon, breast and prostate gland, of chronic inflammatory and autoimmune diseases (e.g. insulin-dependent diabetes mellitus, inflammatory bowel disease, multiple sclerosis), as well as of metabolic disorders (metabolic syndrome, hypertension). The aim of the present review was to provide improved understanding of the molecular and cellular processes by which deficits in calcium and vitamin D cause specific changes in cell and organ functions and thereby increase the risk for chronic diseases of different aetiology. 1,25-Dihydroxyvitamin D(3) and extracellular Ca(++) are both key regulators of proliferation, differentiation and function at the cellular level. However, the efficiency of vitamin D receptor-mediated intracellular signalling is limited by the negative effects of hypovitaminosis D on extrarenal 25-hydroxyvitamin D-1alpha-hydroxylase activity and thus on the production of 1,25-dihydroxyvitamin D(3). Calcium malnutrition eventually causes a decrease in calcium concentration in extracellular fluid compartments, resulting in organ-specific modulation of calcium-sensing receptor activity. Hence, attenuation of signal transduction from the ligand-activated vitamin D receptor and calcium-sensing receptor seems to be the prime mechanism by which calcium and vitamin D insufficiencies cause perturbation of cellular functions in bone, kidney, intestine, mammary and prostate glands, endocrine pancreas, vascular endothelium, and, importantly, in the immune system. The wide range of diseases associated with deficits in calcium and vitamin D in combination with the high prevalence of these conditions represents a special challenge for preventive medicine.

Vitamin D and the elderly

This review summarizes current knowledge on vitamin D status in the elderly with special attention to definition and prevalence of vitamin D insufficiency and deficiency, relationships between vitamin D status and various diseases common in the elderly, and the effects of intervention with vitamin D or vitamin D and calcium. Individual vitamin D status is usually estimated by measuring plasma 25-hydroxyvitamin D (25OHD) levels. However, reference values from normal populations are not applicable for the definition of vitamin D insufficiency or deficiency. Instead vitamin D insufficiency is defined as the lowest threshold value for plasma 25OHD (around 50 nmol/l) that prevents secondary hyperparathyroidism, increased bone turnover, bone mineral loss, or seasonal variations in plasma PTH. Vitamin D deficiency is defined as values below 25 nmol/l. Using these definitions vitamin D deficiency is common among community-dwelling elderly in the developed countries at higher latitudes and very common among institutionalized elderly, geriatric patients and patients with hip fractures. Vitamin D deficiency is an established risk factor for osteoporosis, falls and fractures. Clinical trials have demonstrated that 800 IU (20 microg) per day of vitamin D in combination with 1200 mg calcium effectively reduces the risk of falls and fractures in institutionalized patients. Furthermore, 400 IU (10 microg) per day in combination with 1000 mg calcium or 100 000 IU orally every fourth month without calcium reduces fracture risk in individuals over 65 years of age living at home. Yearly injections of vitamin D seem to have no effect on fracture risk probably because of reduced bioavailability. Simulation studies suggest that fortification of food cannot provide sufficient vitamin D to the elderly without exceeding present conventional safety levels for children. A combination of fortification and individual supplementation is proposed. It is argued that all official programmes should be evaluated scientifically. Epidemiological studies suggest that vitamin D insufficiency is related to a number of other disorders frequently observed among the elderly, such as breast, prostate and colon cancers, type 2 diabetes, and cardiovascular disorders including hypertension. However, apart from hypertension, causality has not been established through randomized intervention studies. It seems that 800 IU (20 microg) vitamin D per day in combination with calcium reduces systolic blood pressure in elderly women.

The nutritional status of astronauts is altered after long-term space flight aboard the International Space Station

Defining optimal nutrient requirements is critical for ensuring crew health during long-duration space exploration missions. Data pertaining to such nutrient requirements are extremely limited. The primary goal of this study was to better understand nutritional changes that occur during long-duration space flight. We examined body composition, bone metabolism, hematology, general blood chemistry, and blood levels of selected vitamins and minerals in 11 astronauts before and after long-duration (128-195 d) space flight aboard the International Space Station. Dietary intake and limited biochemical measures were assessed during flight. Crew members consumed a mean of 80% of their recommended energy intake, and on landing day their body weight was less (P = 0.051) than before flight. Hematocrit, serum iron, ferritin saturation, and transferrin were decreased and serum ferritin was increased after flight (P < 0.05). The finding that other acute-phase proteins were unchanged after flight suggests that the changes in iron metabolism are not likely to be solely a result of an inflammatory response. Urinary 8-hydroxy-2'-deoxyguanosine concentration was greater and RBC superoxide dismutase was less after flight (P < 0.05), indicating increased oxidative damage. Despite vitamin D supplement use during flight, serum 25-hydroxycholecalciferol was decreased after flight (P < 0.01). Bone resorption was increased after flight, as indicated by several markers. Bone formation, assessed by several markers, did not consistently rise 1 d after landing. These data provide evidence that bone loss, compromised vitamin D status, and oxidative damage are among critical nutritional concerns for long-duration space travelers.

Solar radiation, vitamin D and survival rate of colon cancer in Norway

Solar radiation contributes significantly to the status of serum calcidiol (25-hydroxyvitamin D3, 25-(OH)D3) in humans, even at the high latitudes of northern Norway. Thus, in late summer the serum concentration of calcidiol is roughly 50% larger than that in late winter, when the solar radiation in Norway contains too little ultraviolet radiation to induce any synthesis of vitamin D3 in human skin. This seems to influence the prognosis of colon cancer. We here report that the survival rate of colon cancer in men and women, assessed 18 months after diagnosis, is dependent on the season of diagnosis. A high serum concentration of calcidiol at the time of diagnosis, i.e. at the start of conventional therapy, seems to give an increased survival rate. This agrees with cell and animal experiments reported in the literature, as well as with epidemiological data from some countries relating colon cancer survival with latitude and vitamin D3 synthesis in skin. One possible interpretation of the present data is that, the level of calcidiol, or its derivative calcitriol (1alpha,25-dihydroxyvitamin D3, 1alpha,25-(OH)2D3), may act positively in concert with conventional therapies of colon cancer.

Daily Duration of Vitamin D Synthesis in Human Skin with Relation to Latitude, Total Ozone, Altitude, Ground Cover, Aerosols and Cloud Thickness

Vitamin D production in human skin occurs only when incident UV radiation exceeds a certain threshold. From simulations of UV irradiances worldwide and throughout the year, we have studied the dependency of the extent and duration of cutaneous vitamin D production in terms of latitude, time, total ozone, clouds, aerosols, surface reflectivity and altitude. For clear atmospheric conditions, no cutaneous vitamin D production occurs at 51 degrees latitude and higher during some periods of the year. At 70 degrees latitude, vitamin D synthesis can be absent for 5 months. Clouds, aerosols and thick ozone events reduce the duration of vitamin D synthesis considerably, and can suppress vitamin D synthesis completely even at the equator. A web page allowing the computation of the duration of cutaneous vitamin D production worldwide throughout the year, for various atmospheric and surface conditions, is available on the Internet at http://zardoz.nilu.no/~olaeng/fastrt/VitD.html and http://zardoz.nilu.no/~olaeng/fastrt/VitD-ez.html. The computational methodology is outlined here.

Comparisons of Estimated Economic Burdens due to Insufficient Solar Ultraviolet Irradiance and Vitamin D and Excess Solar UV Irradiance for the United States

Vitamin D sufficiency is required for optimal health, and solar ultraviolet B (UVB) irradiance is an important source of vitamin D. UVB and/or vitamin D have been found in observational studies to be associated with reduced risk for over a dozen forms of cancer, multiple sclerosis, osteoporotic fractures, and several other diseases. On the other hand, excess UV irradiance is associated with adverse health outcomes such as cataracts, melanoma, and nonmelanoma skin cancer. Ecologic analyses are used to estimate the fraction of cancer mortality, multiple sclerosis prevalence, and cataract formation that can be prevented or delayed. Estimates from the literature are used for other diseases attributed to excess UV irradiation, additional cancer estimates, and osteoporotic fractures. These results are used to estimate the economic burdens of insufficient UVB irradiation and vitamin D insufficiency as well as excess UV irradiation in the United States for these diseases and conditions. We estimate that 50,000-63,000 individuals in the United States and 19,000-25,000 in the UK die prematurely from cancer annually due to insufficient vitamin D. The U.S. economic burden due to vitamin D insufficiency from inadequate exposure to solar UVB irradiance, diet, and supplements was estimated at $40-56 billion in 2004, whereas the economic burden for excess UV irradiance was estimated at $6-7 billion. These results suggest that increased vitamin D through UVB irradiance, fortification of food, and supplementation could reduce the health care burden in the United States, UK, and elsewhere. Further research is required to confirm these estimates.

Vitamin D and breast cancer: insights from animal models

1alpha,25-dihydroxyvitamin D3 [1,25(OH)2D3[, the biologically active form of vitamin D that interacts with the vitamin D receptor (VDR), is a coordinate regulator of proliferation, differentiation, and survival of breast cancer cells. Therefore, vitamin D compounds that bind and activate VDRs offer promise as therapeutic agents for the treatment of established breast cancer. In addition, epidemiologic, clinical, and animal studies suggested that vitamin D status is important for protection against the development of breast cancer. To elucidate potential biological mechanisms through which vitamin D status might be associated with breast cancer risk, basic research studies focused on defining the molecular effects of vitamin D signaling in the normal mammary gland. Both VDR and vitamin D 1-hydroxylase, the enzyme that generates 1,25(OH)2D3, are expressed and dynamically regulated in the normal mammary gland. Furthermore, studies with mice lacking VDRs established that vitamin D participates in negative growth control of the normal mammary gland and that disruption of VDR signaling is associated with abnormal ductal morphologic features, increased incidence of preneoplastic lesions, and accelerated mammary tumor development. These studies support the concept that suboptimal generation of 1,25(OH)2D3 in the mammary gland might sufficiently deregulate VDR-mediated gene expression to sensitize mammary cells to transformation. In light of these observations, studies to define the most appropriate biomarkers of vitamin D status in relation to protection against breast cancer among human subjects are urgently needed.

Vitamin D, Calcium, and Mammographic Breast Densities

Vitamin D and calcium are being evaluated as potential breast cancer prevention agents. This study reports on the relation of dietary vitamin D and calcium to mammographic breast densities, one of the strongest breast cancer risk factors. Participants were women ages 40 to 60 years who had had a screening mammogram in Rhode Island and eastern Massachusetts (1989–1990). Diet was assessed by semiquantitative food frequency questionnaire, and the percentage of the breast showing densities was estimated visually by a single observer without information on subjects. Multivariate logistic regression was used to compare dietary intakes of vitamin D and calcium between women classified as having few densities (≤30% of the breast with density, n = 287) and extensive densities (≥70% of the breast with density, n = 256). For categories of increasing vitamin D intake (&lt;50, 50–99, 100–199, and ≥200 IU/d), adjusted odds ratios (OR) for extensive densities were 1.00 (reference), 0.51, 0.37, and 0.24, respectively (P for trend = 0.0005). For increasing calcium intake (&lt;500, 500–749, 750–999, and ≥1,000 mg/d), adjusted ORs were 1.00 (reference), 0.63, 0.25, and 0.24, respectively (P for trend = 0.0006). Combination of higher intakes of vitamin D and calcium (≥100 IU/d and ≥750 mg/d, respectively) were associated with a reduction of breast densities (OR, 0.28; 95% confidence interval, 0.15–0.54) compared with those consuming &lt;100 IU/d and &lt;750 mg/d. Increases in vitamin D and calcium intakes were associated with decreases in breast densities, suggesting that dietary vitamin D and calcium could reduce breast cancer risk possibly through influences on breast tissue morphology.

A moderately low phosphate intake may provide health benefits analogous to those conferred by UV light - a further advantage of vegan diets

Although exposure to ultraviolet light is often viewed as pathogenic owing to its role in the genesis of skin cancer and skin aging, there is growing epidemiological evidence that such exposure may decrease risk for a number of more serious cancers, may have a favorable impact on blood pressure and vascular health, and may help to prevent certain autoimmune disorders - in addition to its well-known influence on bone density. Most likely, these health benefits are reflective of improved vitamin D status. Increased synthesis or intake of vitamin D can be expected to down-regulate parathyroid hormone (PTH), and to increase autocrine synthesis of its active metabolite calcitriol in certain tissues; these effects, in turn, may impact cancer risk, vascular health, immune regulation, and bone density through a variety of mechanisms. Presumably, a truly adequate supplemental intake of vitamin D - manyfold higher than the grossly inadequate current RDA - could replicate the benefits of optimal UV exposure, without however damaging the skin. Diets moderately low in bioavailable phosphate - like many vegan diets - might be expected to have a complementary impact on disease risks, inasmuch as serum phosphate suppresses renal calcitriol synthesis while up-regulating that of PTH. A proviso is that the impact of dietary phosphorus on bone health is more equivocal than that of vitamin D. Increased intakes of calcium, on the other hand, down-regulate the production of both PTH and calcitriol - the latter effect may explain why the impact of dietary calcium on cancer risk (excepting colon cancer), hypertension, and autoimmunity is not clearly positive. An overview suggests that a vegan diet supplemented with high-dose vitamin D should increase both systemic and autocrine calcitriol production while suppressing PTH secretion, and thus should represent a highly effective way to achieve the wide-ranging health protection conferred by optimal UV exposure.

Reviews: A Critical Review of Studies on Vitamin D in Relation to Colorectal Cancer

Vitamin D intake has been hypothesized to reduce the risk of several types of cancer. Vitamin D and its analogues have demonstrated anticancer activity in vitro and in animal models. However, the risk of colorectal cancer in relation to dietary vitamin D remains controversial. A literature search was performed for articles on epidemiologic studies of vitamin D and colorectal cancer and the mechanisms involved. Studies that combine multiple sources of vitamin D or examine serum 25(OH)D3 usually find that above-average vitamin D intake and serum metabolite concentrations are associated with significantly reduced incidence of colorectal cancer. A number of mechanisms have been identified through which vitamin D may reduce the risk of colorectal and several other types of cancer. Although studies that include vitamin D from all sources or serum 25(OH)D3 usually show significantly reduced incidence of colorectal cancer in association with vitamin D, analyses limited to dietary vitamin D tend to have mixed results. The likely reason that dietary vitamin D is not a significant risk reduction factor for colorectal cancer in many studies is that dietary sources provide only a portion of total vitamin D, with supplements and synthesis of vitamin D in the skin in association with solar UV-B radiation providing the balance. There is strong evidence from several different lines of investigation supporting the hypothesis that vitamin D may reduce the risk of colorectal cancer. Further study is required to elucidate the mechanisms and develop guidelines for optimal vitamin D sources and serum levels of vitamin D metabolites.

Vitamin D: importance in the prevention of cancers, type 1 diabetes, heart disease, and osteoporosis

The purpose of this review is to put into perspective the many health benefits of vitamin D and the role of vitamin D deficiency in increasing the risk of many common and serious diseases, including some common cancers, type 1 diabetes, cardiovascular disease, and osteoporosis. Numerous epidemiologic studies suggest that exposure to sunlight, which enhances the production of vitamin D(3) in the skin, is important in preventing many chronic diseases. Because very few foods naturally contain vitamin D, sunlight supplies most of our vitamin D requirement. 25-Hydroxyvitamin D [25(OH)D] is the metabolite that should be measured in the blood to determine vitamin D status. Vitamin D deficiency is prevalent in infants who are solely breastfed and who do not receive vitamin D supplementation and in adults of all ages who have increased skin pigmentation or who always wear sun protection or limit their outdoor activities. Vitamin D deficiency is often misdiagnosed as fibromyalgia. A new dietary source of vitamin D is orange juice fortified with vitamin D. Studies in both human and animal models add strength to the hypothesis that the unrecognized epidemic of vitamin D deficiency worldwide is a contributing factor of many chronic debilitating diseases. Greater awareness of the insidious consequences of vitamin D deficiency is needed. Annual measurement of serum 25(OH)D is a reasonable approach to monitoring for vitamin D deficiency. The recommended adequate intakes for vitamin D are inadequate, and, in the absence of exposure to sunlight, a minimum of 1000 IU vitamin D/d is required to maintain a healthy concentration of 25(OH)D in the blood.

Ecologic studies of solar UV-B radiation and cancer mortality rates

Solar ultraviolet B (UV-B) radiation (280-320 nm) has been associated with reduced risk of cancer of the breast, colon, ovary, and prostate, as well as non-Hodgkin's lymphoma (NHL) through the production of vitamin D in papers extending back to 1980. Using data on the geographic distribution of cancer mortality rates in the US, another ten cancers have been added to the list for which UV-B/vitamin D is a risk reduction factor (Grant 2002b; submitted). These associations persist even after additional cancer risk and risk reduction factors such as smoking, urban or rural residence, Hispanic heritage, poverty, dietary factors, and use of nonsteroidal anti-inflammatory drugs are added to the analysis. As a further test of the protective role of UV-B radiation, an ecologic study of cancer mortality rates in Europe with UV-B radiation and dietary factors was conducted. Inverse correlations are found for UV-B radiation for a number of cancers, with those for bladder, breast, endometrial, ovarian, prostate, and renal cancer, and multiple myeloma and NHL having the strongest correlations in this and ongoing multicountry ecologic studies. These studies add further support for the role of UV-B radiation and vitamin D in reducing the risk of a large number of cancers.

Long-latency deficiency disease: insights from calcium and vitamin D

Nutrient intake recommendations and national nutritional policies have focused primarily on prevention of short-latency deficiency diseases. Most nutrient intake recommendations today are based on prevention of the index disease only. However, inadequate intakes of many nutrients are now recognized as contributing to several of the major chronic diseases that affect the populations of the industrialized nations. Often taking many years to manifest themselves, these disease outcomes should be thought of as long-latency deficiency diseases. Sometimes they come about by the same pathophysiologic mechanism that produces the index disease, but sometimes the mechanisms are completely different. Well-documented examples of both short- and long-latency deficiency states involving calcium and vitamin D are described briefly. Then, the insights derived from these nutrients are tentatively applied to folic acid. Discerning the full role of nutrition in long-latency, multifactorial disorders is probably the principal challenge facing nutritional science today. The first component of this challenge is to recognize that inadequate intakes of specific nutrients may produce more than one disease, may produce diseases by more than one mechanism, and may require several years for the consequent morbidity to be sufficiently evident to be clinically recognizable as "disease." Because the intakes required to prevent many of the long-latency disorders are higher than those required to prevent the respective index diseases, recommendations based solely on preventing the index diseases are no longer biologically defensible.

Rickets

Rickets, once thought vanquished, is reappearing. In some less developed countries it hardly went away. This seminar reviews the effects of genes, stage of development, and environment on clinical expression of the disease. Rickets can be secondary to disorders of the gut, pancreas, liver, kidney, or metabolism; however, it is mostly due to nutrient deficiency and we concentrate on this form. Although calcium deficiency contributes in communities where little cows' milk is consumed, deficiency of vitamin D is the main cause. There are three major problems: the promotion of exclusive breastfeeding for long periods without vitamin D supplementation, particularly for babies whose mothers are vitamin D deficient; reduced opportunities for production of the vitamin in the skin because of female modesty and fear of skin cancer; and the high prevalence of rickets in immigrant groups in more temperate regions. A safety net of extra dietary vitamin D should be re-emphasised, not only for children but also for pregnant women. The reason why many immigrant children in temperate zones have vitamin D deficiency is unclear. We speculate that in addition to differences in genetic factors, sun exposure, and skin pigmentation, iron deficiency may affect vitamin D handling in the skin or gut or its intermediary metabolism.

Role of Vitamin D receptor gene in radiation-induced neoplastic transformation of human breast epithelial cell

1 Alpha,25-(OH)(2)-Vitamin D(3), the physiologically active metabolite of Vitamin D is known for its pro-differentiating and antiproliferative activity on various cancer cell lines. It exerts its growth-regulatory effects through binding to the Vitamin D recepter (VDR), a member of the steroid/thyroid/retinoic acid receptor family, which functions as a ligand-dependent transcription factor. There is accumulating evidence that Vitamin D may be an important determinant of both the occurrence and progression of breast cancer. Since radiation is an important etiological factor for breast cancer progression, it is important to study the role of VDR gene in radiation-induced breast carcinogenesis. This study is focused on a human breast tumor model developed by irradiating the spontaneously immortalized MCF-10F cell line with graded doses of high-linear energy transfer (LET) radiation followed by treatment with estrogen. Study of VDR gene by restriction digestion with ApaI, BsmI and TaqI detected no polymorphism but direct sequencing analyses identified few single-base mutations within intron 8 and exon 9 of the gene. Over-expression of the VDR gene was noticed in irradiated and tumorigenic cell lines compared with control. Likewise, immunohistochemical data indicated a significant increase in VDR intensity in irradiated and tumorigenic cell lines. Considering all these evidence, it is likely that VDR can be used as a prognostic marker of tumor progression in radiation- and estrogen-induced breast carcinogenesis.

Vitamin D-3 receptor as a target for breast cancer prevention

The vitamin D-3 receptor (VDR) is a nuclear receptor that modulates gene expression when complexed with its ligand 1-alpha,25-dihydroxycholecalciferol [1,25(OH)(2)-D(3)], which is the biologically active form of vitamin D-3. The cellular effects of VDR signaling include growth arrest, differentiation and/or induction of apoptosis, which indicate that the vitamin D pathway participates in negative-growth regulation. Although much attention has been directed in recent years toward the development of synthetic vitamin D analogs as therapeutic agents for a variety of human cancers including those derived from the mammary gland, studies on vitamin D as a chemopreventive agent for breast cancer have been quite limited. The VDR is expressed in normal mammary gland, where it functions to oppose estrogen-driven proliferation and maintain differentiation; this suggests that 1,25(OH)(2)-D(3) participates in negative-growth regulation of mammary epithelial cells. Furthermore, preclinical studies show that vitamin D compounds can reduce breast cancer development in animals, and human data indicate that both vitamin D status and genetic variations in the VDR may affect breast cancer risk. Collectively, findings from cellular, molecular and population studies suggest that the VDR is a nutritionally modulated growth-regulatory gene that may represent a molecular target for chemoprevention of breast cancer.

Fortification of orange juice with vitamin D: a novel approach for enhancing vitamin D nutritional health

BACKGROUND

Fortification of milk with vitamin D may not be adequate for satisfying the vitamin D requirement because of variability in vitamin D content after fortification and because many persons have milk allergy or lactose intolerance. Additional foods need to be fortified with vitamin D.

OBJECTIVE

We determined whether vitamin D, a fat-soluble vitamin, is bioavailable in orange juice and skim milk, 2 nonfat beverages.

DESIGN

On 3 separate occasions, 18 adults ingested 25 000 IU vitamin D(2) in 240 mL whole milk or skim milk or in 0.1 mL corn oil applied to toast. A separate, double-blind, randomized, controlled trial investigated whether the consumption of orange juice fortified with vitamin D(3) would increase serum 25-hydroxyvitamin D [25(OH)D] concentrations: 14 subjects ingested 240 mL orange juice fortified with 1000 IU vitamin D, and 12 subjects ingested a control orange juice daily for 12 wk.

RESULTS

Peak serum vitamin D(2) concentrations did not differ significantly after the ingestion of vitamin D(2) in whole milk, skim milk, or corn oil on toast. After subjects consumed orange juice fortified with 1000 IU vitamin D(3) daily for 12 wk, serum 25(OH)D(3) concentrations increased by 150%, and serum parathyroid hormone concentrations decreased by 25% compared with baseline; control subjects had a seasonal increase of 45% in 25(OH)D and no significant change in serum parathyroid hormone.

CONCLUSIONS

The fat content of milk does not affect vitamin D bioavailability. Vitamin D fortification at 1000 IU/240 mL orange juice for 12 wk safely increased 25(OH)D(3) concentrations in adults.

Nutrition and lifestyle factors on the risk of developing breast cancer

Aspects of nutrition and lifestyle may be largely responsible for the development of common cancers in Western countries, as indicated by the large differences in breast cancer rates between countries, the striking changes in these rates among migrating populations, and the rapid changes over time within countries. The better informed and increasingly health-conscious population of the present day are intensively seeking to identify and eliminate these putative carcinogenic risk factors and to exploit the preventive effects that have been attributed to certain dietary components. Nutrition and 'lifestyle' may exert its carcinogenic effects indirectly by cell stimulations (alcohol, hormone therapy in postmenopause), inhibition of DNA-repair mechanisms (lack of vitamins), effecting estrogen metabolism (phytoestrogenes), or as promotors to enhance growth of tumours (body mass index). Some 'substances' may act as a carcinogenic itself, for example, aromatic hydrocarbons in tobacco or increased polycyclic aromatic hydrocarbons in well done meat. Individual differences in the effects of nutritional factors on mammary epithelia could be caused by genetic polymorphisms. In this critical review, we focus on current data regarding the effect of nutrition and lifestyle, on the risk of developing breast cancer. A health lifestyle, consisting of 'healthy diet', physical activity, renunciation of stimulants, is recommended from childhood throughout life.

Plato, Sun Tsu, and the Art of War (on cancer). Can we learn from history?

Cancer, in all its guises is on the rise along with the population growth. While not the leading cause of death in the world, it may soon garner that unfortunate honor. In the US, it is second only to heart disease. The 'war on cancer' declared in the US by Richard Milhouse Nixon is not being won. At present, treatment modalities are limited to resection, immunotoxins, radiation, chemotherapy, genomeceuticals, and variations on those themes. It is anticipated that with the emerging human genome data, most of these areas will be expanded, with the possible exception of radiation. However, all these approaches have two things in common. First, they have met with limited success. Second, they all work around the similar idea of containment and eradication in situ of the disease. This paper presents an alternative and novel way of looking at the research and treatment options for cancer taking two lessons from history. First, is Plato's dialectic where 'truth' is uncovered by examining a situation from two opposite directions at once. Second, from Sun Tsu's treaty on the Art of War, where he recommends that when faced with a superior opponent, one method of dealing with the situation is to provoke them, anger them, cause them to move. The second tactic wears out the opponent and presents them in a more favorable situation for assault. It is suggested herein that perhaps cancer can be attacked by first assisting its growth, and causing metastasis to a location more favorable to attack with the common mechanisms cited above.