The relationship between weight change history and 25(OH)D concentrations in adults

Background: although obesity has been consistently associated with lower 25-OH hydroxyvitamin D-25(OH)D-levels, little is known about the effect of weight change on said 25(OH)D levels. Methods: the present analysis was based on data from the National Health and Nutrition Examination Survey. Percent weight changes were calculated from participant-reported maximum lifetime weight and weight in the past year and 10 years ago. Subsequently, general linear models adjusted for potential confounders were assembled to examine 25(OH)D concentrations across percent weight change categories. Results: a total of 6,237 participants with a mean age of 57.5 (SE, 0.2) years comprised the study sample. After adjustment for potential confounders, subjects who have gained weight ≥ 5 % in the past year and 10 years before had on average 4.5 and 5.1 nmol/L lower 25(OH)D levels than those with a stable weight, respectively. Moreover, this association persisted even among participants with adequate vitamin D intake. Notably, subjects who lost weight > 5 % from their maximum reported weight had significantly higher 25(OH)D levels than those who did not. Conclusion: subjects with a stable weight and those who lost weight ≥ 5% from their maximum reported lifetime weight had significantly higher 25(OH)D concentrations than those who did not. Thus, maintaining a healthy weight over time may be an effective strategy to reach optimal serum 25(OH)D levels.