Fascinating new research led by scientists from Massachusetts General Hospital has found a strong link between opioid addiction and vitamin D deficiency. The research indicates subjects with low vitamin D levels may experience heightened euphoric effects from opioids, making them more susceptible to addiction.
Back in 2007 an intriguing study found when ultraviolet light hit the skin it triggered the production of a hormone called beta-endorphin. This endogenous hormone is known to stimulate opioid receptors and is responsible for, among other things, the high one feels following exercise.
While it may seem counter-intuitive for an organism to evolve a mechanism that rewards exposure to cancer-causing UV radiation, the researchers hypothesize this alteration may have helped our ancient ancestors move out of caves during cold times and maintain consistent sun exposure. UV light of course is vital for vitamin D production, so in order to maintain good health and bone strength this specific adaptation helped reward those exposed to the sun.
Initially the discovery helped offer insights into those individuals seemingly addicted to tanning beds. If UV light triggered natural endorphins then it was unsurprising some people would become addicted to sunbathing or artificial UV exposure. But in this new study the researchers set out to investigate whether vitamin D deficiency could play a role in opioid addiction, perhaps by making a person more sensitive to the effects of opioids.
“Our goal in this study was to understand the relationship between vitamin D signaling in the body and UV-seeking and opioid-seeking behaviors,” explains lead author Lajos Kemény.
The first step was to investigate the effect of morphine on mice deficient in vitamin D. One experiment found vitamin-D-deficient mice exposed to frequent doses of morphine exhibited greater drug-seeking and addictive behaviors compared to mice with healthy levels of vitamin D. Low vitamin D levels in the animals also correlated with heightened affective responses to opioids and greater withdrawal symptoms when the drug was withheld.
The researchers then looked to human health records to see if the associations detected in animal studies held up in the real-world. A correlation was indeed found, revealing those with low vitamin D levels were more likely to use opioids. And analyzing records from patients with a diagnosed opioid use disorder (OUD) found they were more likely to suffer from vitamin D deficiency compared to the normal population.
David Fisher, a researcher who has for years been investigating the link between low vitamin D, UV light and natural endorphins, says some of the animal findings from this new study point to a novel pathway for future researchers. Could vitamin D supplementation reduce the risk of addiction in patients prescribed opiates or help amplify the effectiveness of current opioid addiction treatments?
"When we corrected vitamin D levels in the deficient mice, their opioid responses reversed and returned to normal," notes Fisher. "Our results suggests that we may have an opportunity in the public health arena to influence the opioid epidemic.”
A lot more work is needed to directly test some of these therapeutic hypotheses but the implications of these preliminary findings are certainly compelling. Fisher and his team argue the toll of the current opioid epidemic demands timely clinical research investigating these potential new approaches.
“Our results imply that [vitamin-D]-deficient individuals may be at risk for developing tolerance and physiologic opioid dependence more rapidly, experiencing more significant withdrawal, and experiencing greater reward from opioid exposure,” the researchers conclude in the new study. “[Vitamin D] supplementation might have a preventative benefit by decreasing opioid reward and possibly diminishing the risk of OUD.”
The new study was published in the journal Science Advances.
Source: MGH