Our bodies don’t naturally produce bone-building vitamin D. Exposure to the sun’s ultraviolet rays, however, generates this essential hormone. Now consider the conundrum of prehistoric humans.
As they trekked farther and farther north into colder climates, they were less likely to step out of their caves. It was too cold. That meant less sun and vitamin D, which in turn increased their risk of death.
Scientists believe they might have needed a genetic kick in the pants to get them outdoors. Evolution provided that kick in the form of endorphins.
Research shows that our skin produces endorphins when exposed to UV rays. Those endorphin molecules can cause a mild sense of euphoria. That’s because endorphins are related chemically to opioids like morphine and heroin. That also explains why sun-seeking behavior can be addictive.
So, endorphins might be nature’s way of compelling humans to get out into the sun so their bodies can produce vitamin D.
Massachusetts General Hospital researchers have now found that vitamin D deficiency might also make us more susceptible to opioid addiction. It’s believed that it’s somehow tied to that endorphin response. In experiments, a paucity of vitamin D made mice more likely to crave morphine. And the drug worked better at pain relief in the vitamin D-deficient mice.
Scientists also looked at patient records and found those with modestly low levels of vitamin D were 50 percent more likely to use opioids and those with a severe deficiency were 90 percent more likely.
Investigators say this suggests opioid addiction could be treated using inexpensive vitamin supplements.
That’s another good reason to make sure your body gets plenty of vitamin D.