25-hydroxyvitamin D concentration, vitamin D intake and joint symptoms in postmenopausal women.

INTRODUCTION: Low 25-hydroxyvitamin D (25(OH) D) concentrations have been associated with radiologic worsening of osteoarthritis in some reports. However, the results are mixed and few studies have evaluated associations between 25(OH) D concentrations and both total vitamin D intake and clinical joint symptoms. STUDY DESIGN: Cross-sectional analyses of information from a subset of 1993 postmenopausal women obtained at baseline entry in the Women's Health Initiative Calcium plus Vitamin D clinical trial. MAIN OUTCOME MEASURES: 25(OH) D concentration, total vitamin D intake (diet plus supplements), presence and severity of joint pain and joint swelling. RESULTS: The 25(OH) D levels were commonly low with 53% having deficient (<50 nmol/L) and only 17% having sufficient (>72 nmol/L) levels. Joint pain (reported by 74%) and joint swelling (reported by 34%) were also commonly reported. 25(OH) D concentrations were modestly correlated with total vitamin D intake (R=0.29, p<0.0001); however, considerable variability in 25(OH) D concentrations for a given vitamin D intake was seen. In adjusted linear regression models, lower serum 25(OH) D concentrations were associated with higher average joint pain score (P=0.01 for trend) with differences most apparent in the lowest 25(OH) D levels sextile. CONCLUSIONS: Relatively low 25(OH) D levels and a high frequency of joint symptoms were common in this population of postmenopausal women. Total vitamin D intake was only modestly associated with 25(OH) D. Low serum 25(OH) D concentrations were associated with higher joint pain scores. These findings can inform the design of future intervention trials.

Calcium plus vitamin D supplementation and the risk of breast cancer.

BACKGROUND: Although some observational studies have associated higher calcium intake and especially higher vitamin D intake and 25-hydroxyvitamin D levels with lower breast cancer risk, no randomized trial has evaluated these relationships. METHODS: Postmenopausal women (N = 36 282) who were enrolled in a Women's Health Initiative clinical trial were randomly assigned to 1000 mg of elemental calcium with 400 IU of vitamin D(3) daily or placebo for a mean of 7.0 years to determine the effects of supplement use on incidence of hip fracture. Mammograms and breast exams were serially conducted. Invasive breast cancer was a secondary outcome. Baseline serum 25-hydroxyvitamin D levels were assessed in a nested case-control study of 1067 case patients and 1067 control subjects. A Cox proportional hazards model was used to estimate the risk of breast cancer associated with random assignment to calcium with vitamin D(3). Associations between 25-hydroxyvitamin D serum levels and total vitamin D intake, body mass index (BMI), recreational physical activity, and breast cancer risks were evaluated using logistic regression models. Statistical tests were two-sided. RESULTS: Invasive breast cancer incidence was similar in the two groups (528 supplement vs 546 placebo; hazard ratio = 0.96; 95% confidence interval = 0.85 to 1.09). In the nested case-control study, no effect of supplement group assignment on breast cancer risk was seen. Baseline 25-hydroxyvitamin D levels were modestly correlated with total vitamin D intake (diet and supplements) (r = 0.19, P < .001) and were higher among women with lower BMI and higher recreational physical activity (both P < .001). Baseline 25-hydroxyvitamin D levels were not associated with breast cancer risk in analyses that were adjusted for BMI and physical activity (P(trend) = .20). CONCLUSIONS: Calcium and vitamin D supplementation did not reduce invasive breast cancer incidence in postmenopausal women. In addition, 25-hydroxyvitamin D levels were not associated with subsequent breast cancer risk. These findings do not support a relationship between total vitamin D intake and 25-hydroxyvitamin D levels with breast cancer risk.

Cancer-related knowledge, attitudes, and behaviors among Chamorros on Guam.

BACKGROUND: Cancer is the second leading cause of death among Chamorros, the indigenous population of Guam. This study assessed cancer-related knowledge, attitudes, and preventive behaviors (KAB) among Chamorros on the island. METHODS: We conducted a self-administered English language survey regarding cancer-related KAB using a non-probability purposive sample design in 266 self-identified Chamorros (149 women and 117 men) over the age of 50 years. The survey included demographics; health status; access to medical care; and KAB about breast, cervical, prostate, colorectal, lung, and nasopharyngeal cancer. Descriptive statistics and bivariate analysis were used to assess the data. RESULTS: Overall, 83.3% of women reported having a mammogram and 62.8% reported having a Pap smear within the past 2 years. Only 20.3% of men reported having a prostate specific antigen (PSA) test within the past year. Of concern, only 43.1% had heard of PSA. Only 38.3% of participants reported ever having fecal occult blood testing, 15.5% ever having sigmoidoscopy, and 33.1% ever having colonoscopy. Respondents who had a regular source of care were more likely to receive up to date mammography screening (p<0.01). Likewise, those who had visited their doctor within the past year were more likely to be screened for breast (p<0.01), cervical (p<0.05), prostate (p<0.01), and colorectal cancer (p<0.05). In addition, residents living in the south were less likely to report screening for breast (p<0.05), prostate (p<0.05), and colorectal (p<0.01) cancer. CONCLUSION: These results provide important data about Chamorro's KAB that can help to guide a comprehensive cancer control program on Guam.

Calcium plus vitamin D supplementation and the risk of fractures.

BACKGROUND: The efficacy of calcium with vitamin D supplementation for preventing hip and other fractures in healthy postmenopausal women remains equivocal. METHODS: We recruited 36,282 postmenopausal women, 50 to 79 years of age, who were already enrolled in a Women's Health Initiative (WHI) clinical trial. We randomly assigned participants to receive 1000 mg of elemental [corrected] calcium as calcium carbonate with 400 IU of vitamin D3 daily or placebo. Fractures were ascertained for an average follow-up period of 7.0 years. Bone density was measured at three WHI centers. RESULTS: Hip bone density was 1.06 percent higher in the calcium plus vitamin D group than in the placebo group (P<0.01). Intention-to-treat analysis indicated that participants receiving calcium plus vitamin D supplementation had a hazard ratio of 0.88 for hip fracture (95 percent confidence interval, 0.72 to 1.08), 0.90 for clinical spine fracture (0.74 to 1.10), and 0.96 for total fractures (0.91 to 1.02). The risk of renal calculi increased with calcium plus vitamin D (hazard ratio, 1.17; 95 percent confidence interval, 1.02 to 1.34). Censoring data from women when they ceased to adhere to the study medication reduced the hazard ratio for hip fracture to 0.71 (95 percent confidence interval, 0.52 to 0.97). Effects did not vary significantly according to prerandomization serum vitamin D levels. CONCLUSIONS: Among healthy postmenopausal women, calcium with vitamin D supplementation resulted in a small but significant improvement in hip bone density, did not significantly reduce hip fracture, and increased the risk of kidney stones. (ClinicalTrials.gov number, NCT00000611.).

Calcium plus vitamin D supplementation and the risk of colorectal cancer.

BACKGROUND: Higher intake of calcium and vitamin D has been associated with a reduced risk of colorectal cancer in epidemiologic studies and polyp recurrence in polyp-prevention trials. However, randomized-trial evidence that calcium with vitamin D supplementation is beneficial in the primary prevention of colorectal cancer is lacking. METHODS: We conducted a randomized, double-blind, placebo-controlled trial involving 36,282 postmenopausal women from 40 Women's Health Initiative centers: 18,176 women received 500 mg of elemental calcium as calcium carbonate with 200 IU of vitamin D3 [corrected] twice daily (1000 mg of elemental calcium and 400 IU of vitamin D3) and 18,106 received a matching placebo for an average of 7.0 years. The incidence of pathologically confirmed colorectal cancer was the designated secondary outcome. Baseline levels of serum 25-hydroxyvitamin D were assessed in a nested case-control study. RESULTS: The incidence of invasive colorectal cancer did not differ significantly between women assigned to calcium plus vitamin D supplementation and those assigned to placebo (168 and 154 cases; hazard ratio, 1.08; 95 percent confidence interval, 0.86 to 1.34; P=0.51), and the tumor characteristics were similar in the two groups. The frequency of colorectal-cancer screening and abdominal symptoms was similar in the two groups. There were no significant treatment interactions with baseline characteristics. CONCLUSIONS: Daily supplementation of calcium with vitamin D for seven years had no effect on the incidence of colorectal cancer among postmenopausal women. The long latency associated with the development of colorectal cancer, along with the seven-year duration of the trial, may have contributed to this null finding. Ongoing follow-up will assess the longer-term effect of this intervention. (ClinicalTrials.gov number, NCT00000611.).

Addressing the cancer control needs of Pacific Islanders: experience of the Pacific Islander Cancer Control Network.

PURPOSE: This paper describes the accomplishments of the Pacific Islander Cancer Control Network (PICCN). PICCN's objectives fall under two broad categories: increasing cancer awareness and enhancing cancer control research among Samoans, Tongans, and Chamorros. METHODS: PICCN established an infrastructure for addressing the goals that include the University of California, Irvine; the UCI Chao Family Comprehensive Cancer Center; and community-based organizations (CBOs) in areas where large numbers of Pacific Islanders live. Activities that increase cancer awareness include assessing existing cancer education materials, developing new culturally-sensitive materials, and distributing the materials in a culturally-sensitive manner. Activities that enhance cancer control research include training Pacific Islander investigators and providing them with mentors to help with the development of research projects. RESULTS: During the four project years, PICCN has conducted more than 180 cancer awareness activities in its six study sites: Carson, CA; San Mateo, CA; San Diego, CA; Salt Lake City, UT; American Samoa; and Guam. PICCN members have also participated in conferences and lead discussions about the importance of clinical trials for Pacific Islanders. In addition, the Network has trained nine Pacific Islander investigators (three individuals from each ethnic group) in its cancer control academy. Finally, PICCN investigators are conducting pilot research projects that will answer important questions regarding the cancer control needs of these Pacific Islanders and set the stage for interventions aimed at addressing the needs. CONCLUSION: PICCN is advancing the national goal of eliminating cancer-related health disparities through its cancer awareness and research activities for Pacific Islanders.

The Pacific Islander Cancer Control Network's role in cancer awareness, research and training.

PURPOSE: The Pacific Islander Cancer Control Network (PICCN) is one of the 18 Special Populations Networks recently established by the National Cancer Institute (NCI) to address the cancer control needs of America's medically under-served populations. The PICCN focuses on three Pacific Islander groups: Samoans, Guamanians/Chamorros, and Tongan Americans. The program provides an infrastructure for collaboration between an academic institution, the University of California, Irvine; an NCI designated cancer center, the Chao Family Comprehensive Cancer Center; community-based organizations; and other agencies concerned with the health of Pacific Islanders. METHODS: The PICCN's objectives include improving cancer awareness, enhancing recruitment to clinical trials, increasing the number of cancer control investigators, and encouraging more research among these Pacific Islanders. The activities that increase cancer awareness include assessing existing cancer education materials aimed at Pacific Islanders, working with the NCI's Cancer Information Service to modify existing materials, developing new culturally-sensitive materials, and distributing the materials in a culturally-sensitive manner. PRINCIPAL FINDINGS: The PICCN enhances recruitment of Pacific Islanders to clinical trials by establishing relationships with cancer centers, making them aware of existing cancer center studies, and developing culturally appropriate recruitment materials when necessary. The network plans to increase the number of Pacific Islander investigators and encourage more research among Pacific Islanders by identifying potential investigators, informing them about existing cancer control training opportunities, developing a new training opportunity, and providing mentors to help with the development of pilot projects and RO1 applications. CONCLUSION: Through these efforts, the PICCN is addressing the goal of eliminating health disparities among ethnic and racial minorities in this country.