[Introductory text in lieu of abstract.] Diabetes rates are increasing around the world, mainly driven by increasing levels of obesity. The dilemma for diabetes prevention is that the main risk factor – obesity – is a product of our modern lifestyle (the so-called obesogenic environment). Immediate prospects for changing the environment to reverse rising obesity levels are not promising, and there is a need to consider other options for preventing diabetes.
One of these options – vitamin D – is addressed in the article by Forouhi et al. in this issue of Diabetes.* The sun is the primary source of vitamin D, which is synthesized endogenously in skin to produce cholecalficerol (vitamin D3), although a small proportion (less than 20%) of vitamin D comes through diet from a limited range of foods (in the form of ergocalciferol [vitamin D2] and vitamin D3) . The main marker of vitamin D status is the metabolite 25-hydroxyvitamin D [25(OH)D], which is synthesized in the liver.
The epidemiology of vitamin D status is inverse to that of diabetes, since:
• Blood levels of 25(OH)D decline with age and are lower in populations with increased skin pigmentation, such as African Americans and South Asians, and in people with obesity,
• While diabetes increases with age and obesity and is higher in these ethnic groups….
Source: Diabetes, October 2008, 57(10): 2465-2566. Robert Scragg , School of Population Health, University of Auckland, Auckland, New Zealand. [E-mail: email@example.com]
* Diabetes, October 2008; 57: 2619-2625. “Baseline Serum 25-Hydroxy Vitamin D Is Predictive of Future Glycemic Status and Insulin Resistance: The Medical Research Council Ely Prospective Study 1990–2000” Forouhi G, et al. Institute of Metabolic Science, Cambridge; Bart's and the London School of Medicine and Dentistry, London, UK.