The Dependency of Vitamin D Status on Body Mass Index, Gender, Age and Season

Background: Obesity is a rapidly growing health problem in most developed countries. Excess body weight is a risk factor for many somatic and even psychological disorders, including cardiovascular disease, type 2 diabetes mellitus, osteoarthritis and several cancer types. Recently, overweight and obesity have been shown to be related to low vitamin D status. Materials and Methods: The 25(OH)D-3 status was analyzed in a population of 2,126 patients registered in a Metabolic and Medical Lifestyle Management Clinic in Oslo, Norway. Seasonal variation and prevalence of vitamin D deficiency were assessed in different body mass index (BMI), sex and age categories. Results: For both sexes and both age groups (<50 years and >= 50 years) there was a significant decrease of serum 25(OH)D-3 levels with increasing BMI. Surprisingly, not only were the 25(OH)D-3 levels negatively correlated with BMI, but the serum 1,25(OH)(2)D-3 levels were also. The seasonal variation of serum 25(OH)(2)D-3 was highest in young (<50 years) non-obese men. The prevalence of vitamin D deficiency was highest in individuals with BMI >= 40, being as high as 32% among women and 46% among men. Conclusion: The 25(OH)D-3 level, as well as its seasonal variation and the prevalence of vitamin D deficiency, are all dependent on BML and age separately. The results of the study suggest that 1 in 3 women and 1 in 2 men with BMI >= 40 are vitamin D deficient.