A study published recently in The Journal of Women’s Health took a look at associations between weight changes in elderly women and 25(OH)D levels.
This longitudinal study examined a prospective cohort of 4659 women over the age of 65 for associations between serum 25(OH)D levels and changes in weight. All the women had their 25(OH)D levels measured and were weighed at baseline. Measurements of weight were repeated at both year six and year ten examinations. 1054 women were randomly selected to have their 25(OH)D levels retested.
The women were divided into two groups, those with 25(OH)D levels < 30 ng/mL and those with levels > 30 ng/mL. Changes in weight were recorded and participants were characterized into one of three groups: loss, gain, or stable. They made adjustments for baseline weight, age, season, years of follow-up, and multiple other confounders.
Overall, there was no association between 25(OH)D status and weight change. However, there was a significant interaction between 25(OH)D status and weight change category. In women who gained weight, those with 25(OH)D levels > 30 ng/mL gained an average of 16.4 pounds, while those with 25(OH)D levels < 30 ng/mL gained an average of 18.5 pounds. No interactions between 25(OH)D levels and weight change were observed in the women who lost weight or remained weight stable.
These results were consistent with the authors’ predictions that higher 25(OH)D levels would be associated with less weight gain over time. In previous trials, patients with higher levels of 25(OH)D lost more weight and more fat than patients with lower 25(OH)D levels. The authors note that vitamin D receptors are present on human adipocytes and that data from epidemiologic, weight loss, animal, and in vitro studies suggest it plays a role in weight regulation. Additionally they note that vitamin D appears to influence lipogensis, lipolysis, adipogenesis, and adipocyte gene transcription in vitro.
They hypothesize that from an evolutionary perspective, the decreased sun exposure in fall and winter could serve as a signal, via reduced 25(OH)D production, to increase fat stores for the coming winter and reduction in the food supply.
In conclusion, the statistically significant association found between higher levels of 25(OH)D and less weight gain among elderly women corroborate previous findings in weight loss trials involving vitamin D. This study provides evidence for a causal role of 25(OH)D levels in weight gain. Further studies are necessary to see if the same effects are observed in men and younger populations, but it appears staving off age-related weight loss may be yet another benefit to keeping your vitamin D levels optimized.