In this issue of Public Health Nutrition is a much anticipated review of the recent literature on vitamin D by Professor Robert Scragg⁽Reference Scragg¹⁾. The November 2010 report by the Institute of Medicine (IoM)⁽²⁾ sparked much controversy over the adequacy of the newly released recommendations for vitamin D intake. In April we published a series of letters critical of the IoM report, followed by a rebuttal in May from the chair of the committee that authored the report. The review by Professor Scragg offers another, balanced perspective on current knowledge of vitamin D's potential effects on chronic diseases and mortality.

Other articles in this issue fall primarily into two broad categories: dietary patterns and food acquisition. The use of principal components or factor analysis to empirically characterize dietary patterns was considered esoteric 15 years ago. But its use has increased exponentially over the past decade, as evidenced by the articles in the current issue, which describe dietary patterns among pregnant women in Crete⁽Reference Chatzi, Melaki and Sarri³⁾, adults in Lebanon⁽Reference Naja, Nasreddine and Itani⁴⁾, low-income adults in Brazil⁽Reference Cunha, Sichieri and Rodrigues de Almeida⁵⁾ and Hispanic women in the USA⁽Reference Park, Neckerman and Quinn⁶⁾. These articles, international in scope, demonstrate how recognizable and ubiquitous a ‘Western’ dietary pattern is. Principal components analyses characterize only one dimension of a dietary pattern – common combinations of frequently consumed foods. Other dimensions of dietary patterns should not be neglected, and they are acknowledged in this issue as well: number of meals and snacks among Luo, Kamba and Maasai adults in Kenya⁽Reference Hansen, Christensen and Larsson⁷⁾; meals consumed and skipped among children in Norway⁽Reference Øverby, Stea and Vik⁸⁾; and the context of dietary intake – whether consumed with family or in front of a television⁽Reference Sobal and Hanson^9, Reference Rey-López, Vicente-Rodríguez and Répásy¹⁰⁾.

A second broad category of articles in this issue covers food acquisition. Researchers and practitioners are becoming increasingly aware of the need for valid measures of the food environment, and valid estimates of its association with food procurement and dietary intake. This issue presents several examples of how food environment can be conceptualized – in terms of the number and density of certain types of stores, in terms of various measures of accessibility to food venues, as an immigrant enclave, recognizing the contribution of home gardens and farmers’ markets⁽Reference Setala, Gittelsohn and Speakman^11–Reference Campbell, Akhter and Sun¹⁵⁾. Food cost also strongly influences food acquisition decisions, and two articles⁽Reference Rydén and Hagfors^16, Reference Katz, Doughty and Njike¹⁷⁾ address this under a new topic heading in our journal, on Health Economy. Patterns of food purchasing are also addressed in two other articles⁽Reference D'Angelo, Suratkar and Song^18, Reference Thompson, Bentley and Davis¹⁹⁾. Given the importance of considering the interaction between individuals and their environment, rather than simply describing the environment itself, we believe that decision making on food purchases will emerge as another dominant area of research in years to come.

Together, the articles provide a unique snapshot of dietary patterns and food environments across an international spectrum. They also serve to inform readers of current approaches on conceptualizing and quantifying dietary patterns and food environment measures in these evolving fields of study.