The Effect of Vitamin D Supplementation on Circadian Rhythm Parameters
Alternative Title
Abstract
Circadian rhythms are the physical, behavioral, and physiological changes an organism experiences over a 24-hour cycle. These rhythms are essential to health, as previous research shows that disrupted rhythms are related to the development of pathologic conditions such as cancer, diabetes, and cardiovascular disease. It’s possible to reset or strengthen rhythms with factors called entrainment factors, including daylight, exercise, and dietary habits. Certain supplements, such as melatonin and vitamin B12 have been shown to positively affect circadian rhythms, but research on other potential supplements is limited. Vitamin D is a supplement that replaces or adds to the natural vitamin D our body produces. It has the potential to affect rhythms since it’s synthesized in response to one of our entrainment factors, daylight, and is important in the synthesis of melatonin, a hormone known to help synchronize our clocks. Therefore, this study will examine if vitamin D supplementation has an effect on circadian rhythm parameters. To determine this, 20-25 individuals will be recruited to supplement with vitamin D for four weeks.
Participants will provide a small blood sample for the measurement of plasma vitamin D, take a survey to self-report their sleep and mood, and wear an ActTrust2 (Condor Instruments) watch to collect information on the timing, period, and amplitude of circadian rhythms. Data will be collected before and after supplementation, and student’s paired t-tests will be run to determine the presence of statistically significant differences between pre- and post-supplementation measures. We predict that vitamin D supplementation will provide the subjects with improved sleep quality and circadian rhythm parameters.