Background: Vitamin D is an immune modulator that may play a role in thyroid related autoimmunity. Methods: We analyzed a US population based dataset to determine the relationship between serum 25-hydroxyvitamin D (25OHD) and thyroid hormones while assessing the effects of autoimmunity and BMI. Results: 25OHD did not correlate significantly with any thyroid related measure. 25OHD levels stratified by thyroid antibody status were not statistically different between antibody positive and negative groups. The mean 25OHD levels of lean, overweight, and obese groups defined by BMI were lower than those of the normal group. Only the mean thyroid stimulating hormone (TSH) value in the obese group was significantly higher than the normal group. Conclusions: We conclude that thyroid related measures and 25OHD serum levels are not related.