Dose response to vitamin D supplementation in African Americans: results of a 4-arm, randomized, placebo-controlled trial.

BACKGROUND: Association studies have suggested that lower circulating 25-hydroxyvitamin D [25(OH)D] in African Americans may partially underlie higher rates of cardiovascular disease and cancer in this population. Nonetheless, the relation between vitamin D supplementation and 25(OH)D concentrations in African Americans remains undefined. OBJECTIVE: Our primary objective was to determine the dose-response relation between vitamin D and plasma 25(OH)D. DESIGN: A total of 328 African Americans in Boston, MA, were enrolled over 3 winters from 2007 to 2010 and randomly assigned to receive a placebo or 1000, 2000, or 4000 IU vitamin D3/d for 3 mo. Subjects completed sociodemographic and dietary questionnaires, and plasma samples were drawn at baseline and 3 and 6 mo. RESULTS: Median plasma 25(OH)D concentrations at baseline were 15.1, 16.2, 13.9, and 15.7 ng/mL for subjects randomly assigned to receive the placebo or 1000, 2000, or 4000 IU/d, respectively (P = 0.63). The median plasma 25(OH)D concentration at 3 mo differed significantly between supplementation arms at 13.7, 29.7, 34.8, and 45.9 ng/mL, respectively (P < 0.001). An estimated 1640 IU vitamin D3/d was needed to raise the plasma 25(OH)D concentration to ≥ 20 ng/mL in ≥ 97.5% of participants, whereas a dose of 4000 IU/d was needed to achieve concentrations ≥ 33 ng/mL in ≥ 80% of subjects. No significant hypercalcemia was seen in a subset of participants. CONCLUSIONS: Within African Americans, an estimated 1640 IU vitamin D3/d was required to achieve concentrations of plasma 25(OH)D recommended by the Institute of Medicine, whereas 4000 IU/d was needed to reach concentrations predicted to reduce cancer and cardiovascular disease risk in prospective observational studies. These results may be helpful for informing future trials of disease prevention.

Dimensions of religiousness and cancer screening behaviors among church-going Latinas.

Churches are a promising setting through which to reach Latinas with cancer control efforts. A better understanding of the dimensions of religiousness that impact health behaviors could inform efforts to tailor cancer control programs for this setting. The purpose of this study was to explore relationships between dimensions of religiousness with adherence to cancer screening recommendations among church-going Latinas. Female Spanish-speaking members, aged 18 and older from a Baptist church in Boston, Massachusetts (N = 78), were interviewed about cancer screening behaviors and dimensions of religiousness. We examined adherence to individual cancer screening tests (mammography, Pap test, and colonoscopy), as well as adherence to all screening tests for which participants were age-eligible. Dimensions of religiousness assessed included church participation, religious support, active and passive spiritual health locus of control, and positive and negative religious coping. Results showed that roughly half (46 %) of the sample had not received all of the cancer screening tests for which they were age-eligible. In multivariate analyses, positive religious coping was significantly associated with adherence to all age-appropriate screening (OR = 5.30, p < .01). Additional research is warranted to replicate these results in larger, more representative samples and to examine the extent to which enhancement of religious coping could increase the impact of cancer control interventions for Latinas.

Parental perceptions of a motivational interviewing-based pediatric obesity prevention intervention.

Motivational interviewing (MI) shows promise for pediatric obesity prevention, but few studies address parental perceptions of MI. The aim of this study was to identify correlates of parental perceptions of helpfulness of and satisfaction with a MI-based pediatric obesity prevention intervention. We studied 253 children 2 to 6 years of age in the intervention arm of High Five for Kids, a primary care-based randomized controlled trial. In multivariable models, parents born outside the United States (odds ratio [OR] = 8.81; 95% confidence interval [CI] = 2.44, 31.8), with lower household income (OR = 3.60; 95% CI = 1.03, 12.55), and with higher BMI (OR = 2.86; 95% CI = 1.07, 7.65) were more likely to perceive MI-based visits as helpful in improving children's obesity-related behaviors after the first year of the intervention. Parents of female (vs male), black (vs white), and Latino (vs white) children had lower intervention satisfaction. Our findings underscore the importance of tailoring pediatric obesity prevention efforts to target populations.

Implementation of a cancer prevention program for working class, multiethnic populations.

BACKGROUND: This paper describes the implementation of the Healthy Directions-Health Centers intervention and examines the characteristics of participants associated with completion of intervention activities. Healthy Directions-Health Centers was designed to address social contextual factors relevant to cancer prevention interventions for working class, multi-ethnic populations. METHODS: Ten community health centers were paired and randomly assigned to intervention or control. Patients who resided in low income, multi-ethnic neighborhoods were approached for participation. This study targeted fruit and vegetable consumption, red meat consumption, multi-vitamin intake, and physical activity. The intervention components consisted of: (1) a brief study endorsement from a clinician; (2) an in-person counseling session with a health advisor; (3) four follow-up telephone counseling sessions; and (4) multiple distributions of tailored materials. RESULTS: Among the 1,088 intervention group participants, 978 participants (90%) completed at least five out of six intervention activities. Participants who missed clinical appointments were less likely to complete all components of the intervention. Participant characteristics that predicted receipt of clinician endorsement differed from characteristics that predicted completion of health advisor activities. Low acculturation did not present a barrier to delivery of the intervention once the participant was enrolled. CONCLUSIONS: Collection and reporting on process evaluation results can help explain variations in program implementation.