Adiponectin is a peptide hormone secreted by fat tissue that is associated with favorable cardio-metabolic profiles. The hormone plays a role in better outcomes in type 2 diabetes, obesity, atherosclerosis and NAFLD. That is, the higher your adiponectin, the better your health.
In July 2011, Dr. Anand Vaidya and colleagues at Harvard University analyzed two large groups of Americans to discover that the higher your vitamin D level, the higher your adiponectin. Previous studies had found the association, but the Harvard group was able to correct for all known potential confounders and still found a strong positive relationship.
Vaidya A, Williams JS, Forman JP. The Independent Association Between 25-Hydroxyvitamin D and Adiponectin and Its Relation With BMI in Two Large Cohorts: The NHS and the HPFS. Obesity (Silver Spring). 2011 Jul 14. doi: 10.1038/oby.2011.210. [Epub ahead of print]
This was a cross-sectional study, so their study can’t tell us if vitamin D is increasing adiponectin, if adiponectin is increasing vitamin D, or if a third unidentified factor is increasing both. However, I’d bet the ranch that future controlled trials will find that adequate doses of vitamin D (around 10,000 IU/day as the subjects will be obese) will increase adiponectin levels.
If you are obese, remember that 5,000 IU/day is probably not an adequate dose of vitamin D, at least for the first year or two. Sometimes very obese patients need 10,000 IU/day just to obtain vitamin D levels of 40-60 ng/ml. People on such a dosage need to have vitamin D levels checked twice a year to be sure that their vitamin D levels do not precipitously raise on such a dose.
I also bet that obese people supplementing with 10,000 IU/day will notice a slow but steady reduction in their weight. If that has been your experience, or if such supplementation has had no effect on your weight, I’d like to hear from you. I can’t promise that I will reply to all responses, but I’d much like to try.