Can Vitamin D deficiency contribute to opioid use? Though seemingly unrelated substances, the two interestingly mirror each other in effects and metabolism. Vitamin D deficiency can lead to weakness, pain, and depression. Both can interact with addiction receptors in the brain. For these reasons, some evolutionary thinkers argue sunlight, the primary source of Vitamin D, may have emerged as the very first addiction. In this framework, modern opioid use could mirror sun exposure, but without the benefits and regulation which Vitamin D provides. Thus, one's natural Vitamin D levels may be very important to explaining their interactions with opioids. This paper parallels previous medical and epidemiological literature attempting to demonstrate how Vitamin D mediates the strength of opioids. Using 2003--2004 U.S. NHANES prescription use, health, and demographic data for individuals aged 20 to 84, this paper measures the impact of Vitamin D deficiency on the propensity of opioid use. A control function approach is used, leveraging milk consumption to relieve endogeneity concerns in previous studies. Unlike previous findings, we do not observe any significant effect from Vitamin D levels.
