Vitamin D insufficiency
Canadians living in northern latitudes may be at increased risk of vitamin D insufficiency and its associated risk of osteoporotic fractures. Diana Rucker and coauthors investigated the prevalence of vitamin D insufficiency in a group of adults (60 men, 128 women) in Calgary aged 27–89 years who were otherwise healthy and not taking vitamin D supplements. Blood samples were collected every 3 months for a year and tested for several metabolic markers, including vitamin D metabolites, calcium and parathyroid hormone (PTH). About one-third of the subjects (n = 64) had vitamin D insufficiency (25-hydroxyvitamin D [25(OH)D] level < 40 nmol/L) at some point during the year. However, the proportion climbed to 97% when a different threshold for insufficiency (25[OH]D level of 80 nmol/L, a level below which PTH levels begin to rise) was used. As expected, the mean 25(OH)D level rose in the spring and summer and declined in the fall. The authors call for more aggressive vitamin D supplementation in the general population. In a related commentary Reinhold Vieth and Donald Fraser echo this call and give recommendations for the dietary supplementation of healthy adults.
See pages 1517 and 1541
Functional foods
Many consumers are looking to food to be not just simple nutrition but a potential source of health benefits as well. In the seventh article in our nutrition series, Peter Jones explains that “functional foods” are distinct from fortified foods and natural health supplements in that they contain bioactive elements that may reduce the risk of disease. Jones reviews the regulations regarding health claims for such functional foods in Canada and the United States and describes several examples, including oat bran fibre, soy protein, fish oil fatty acids, and plant sterols and stanols.
See page 1555
Evidence-based medicine in primary care
For over a decade proponents of evidence-based medicine (EBM) have advocated that principles guiding clinical practice be based primarily on the results of clinical research rather than on just physiological correlates, intuition and experience. Wayne Putnam and colleagues conducted a qualitative study to investigate how EBM is viewed and being used in the primary care setting. They conducted 9 focus groups (3 each in rural, semi-rural and urban settings) involving a total of 50 family physicians in Nova Scotia. One main theme that emerged related to the use of evidence in the clinical encounter, with many physicians describing evidence as influencing physicians' and patients' decision-making. Another emerging theme suggested that physicians appreciate evidence that is collected and appraised as part of summaries such as clinical practice guidelines and that accumulated evidence in a field tends to be more influential than individual research studies. The authors suggest that EBM has an important role in primary care but that its application is often adjusted to take into account the views, interests and needs of the patient.
See page 1525
Chiropractic students' attitudes toward vaccination
Although the Canadian Chiropractic Association and the Canadian Memorial Chiropractic College (CMCC) officially endorse vaccination, the attitudes of chiropractors toward it are unknown. Jason Busse and colleagues surveyed CMCC students enrolled in the 1999/2000 academic year regarding their attitudes and their sources of information about vaccination. Among the students who participated (467 of 621 enrolled) attitudes were most positive among the first-year students: 60.7% agreed with it and 4.5% were against it, as compared with 39.5% and 29.4% respectively of fourth-year students. Negative attitudes were most prevalent among students who relied primarily on information sources such as “informal” extracurricular presentations at the college rather than on core CMCC or university lectures. The authors express concern over the prevalence of anti-vaccination attitudes and the potential effect on patients.
In a related commentary Robert Pless and Beth Hibbs state that antivaccine attitudes are not the norm and suggest that promotion of vaccination programs may be an ideal model for initiating more cooperation and learning between chiropractors and physicians.
See pages 1531 and 1544
Figure.
Figure.
Photo by: Lianne Friesen and Nicholas Woolridge
Figure.
Photo by: Corbis