OBJECTIVE: To identify different dietary patterns in Norway using a combination of cluster and factor analysis. DESIGN: Cross-sectional study. SETTING: Nation-wide, population-based study. SUBJECTS: The Norwegian EPIC cohort is a subcohort of the Norwegian Women and Cancer study (NOWAC), and consist 37.226 women aged 41-56 y who answered a food frequency questionnaire (FFQ) in 1998. INTERVENTIONS: The associations among 50 food variables were first investigated by using principal component analysis. Five important factors were found. The five principal components were then used as input in the cluster analysis. Different socioeconomic and lifestyle variables were examined. RESULTS: Six clusters of dietary patterns were found, and were labelled accordingly: 'traditional fish eaters', 'healthy eaters', 'average, less fish, less healthy', 'Western', 'traditional bread eaters', and 'alcohol users'. The traditional fish eaters and the traditional bread eaters were both highly represented in the north and west of Norway and were more likely to be present among persons with lower income and lower education. The healthy and the alcohol drinkers were found mostly in the south and east and were more likely to have higher income. Persons in the alcohol group were more likely to be current smokers. The western group had the highest percentage of three or more persons in the household and the shortest time since last birth, indicating that families with children dominate this group. CONCLUSION: Our data indicate six different dietary patterns in Norway, each with different socio-demographic and lifestyle characteristics. SPONSORSHIP: The Norwegian Cancer Society (E 04038/006).
OBJECTIVE: To determine the vitamin D status of middle-aged women living in the Norwegian arctic and its relationship with vitamin D intake and exposure to ultraviolet (UV) radiation. DESIGN: Cross-sectional study. SUBJECTS AND SETTING: This study is based on measurements of 25-hydroxyvitamin D (25(OH)D) levels in a sub-sample of the Norwegian component of the EPIC biological bank, which consists of blood samples from a random selection of participants in the Norwegian Women and Cancer Study. From November 2001 until June 2002, 309 blood samples were collected from a total of 443 invited middle-aged women (44-59 years) in northern Norway (65-71 degrees N) (crude response rate, 69.8%). Questionnaire data provided information on dietary sources of vitamin D and UV exposure. RESULTS: Median plasma 25(OH)D concentration for the whole group was 55.0 nmol l(-1) (range 8.1-142.8 nmol l(-1)). Vitamin D intake was a significant predictor of 25(OH)D status (P=0.0003). The time of the year when the blood sample was collected significantly predicted plasma 25(OH)D level (P=0.005). Levels of 25(OH)D were positively associated (P=0.0002) with estimated hours per day of exposure to UV-B radiation. Residing in northern Norway during the summer prior to blood sampling was negatively associated with 25(OH)D concentration (P=0.001). The prevalence of moderate hypovitaminosis D was highest in January-February, when a quarter of the participants had 25(OH)D concentrations